{ "instance": { "kop-10q_20200331.htm": { "axisCustom": 0, "axisStandard": 30, "contextCount": 240, "dts": { "calculationLink": { "local": [ "kop-20200331_cal.xml" ] }, "definitionLink": { "local": [ "kop-20200331_def.xml" ], "remote": [ "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-eedm-def-2019-01-31.xml", "http://xbrl.fasb.org/srt/2019/elts/srt-eedm1-def-2019-01-31.xml" ] }, "inline": { "local": [ "kop-10q_20200331.htm" ] }, "labelLink": { "local": [ "kop-20200331_lab.xml" ], "remote": [ "http://xbrl.fasb.org/srt/2019/elts/srt-doc-2019-01-31.xml", "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-doc-2019-01-31.xml", "https://xbrl.sec.gov/dei/2019/dei-doc-2019-01-31.xml" ] }, "presentationLink": { "local": [ "kop-20200331_pre.xml" ] }, "referenceLink": { "remote": [ "https://xbrl.sec.gov/dei/2019/dei-ref-2019-01-31.xml", "http://xbrl.fasb.org/srt/2019/elts/srt-ref-2019-01-31.xml", "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-ref-2019-01-31.xml" ] }, "schema": { "local": [ "kop-20200331.xsd" ], "remote": [ "http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd", "http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd", "http://www.xbrl.org/2003/xl-2003-12-31.xsd", "http://www.xbrl.org/2003/xlink-2003-12-31.xsd", "http://www.xbrl.org/2005/xbrldt-2005.xsd", "https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd", "http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd", "https://xbrl.sec.gov/currency/2019/currency-2019-01-31.xsd", "https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd", "http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd", "https://xbrl.sec.gov/exch/2019/exch-2019-01-31.xsd", "http://www.xbrl.org/lrr/arcrole/factExplanatory-2009-12-16.xsd", "http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd", "http://www.xbrl.org/lrr/role/net-2009-12-16.xsd", "https://xbrl.sec.gov/naics/2017/naics-2017-01-31.xsd", "https://xbrl.sec.gov/sic/2011/sic-2011-01-31.xsd", "http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd", "http://www.xbrl.org/2006/ref-2006-02-27.xsd", "http://xbrl.fasb.org/srt/2019/elts/srt-types-2019-01-31.xsd", "http://xbrl.fasb.org/srt/2019/elts/srt-roles-2019-01-31.xsd", "https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd", "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd", "http://xbrl.fasb.org/us-gaap/2019/elts/us-roles-2019-01-31.xsd", "http://xbrl.fasb.org/us-gaap/2019/elts/us-types-2019-01-31.xsd", "http://www.xbrl.org/lrr/role/deprecated-2009-12-16.xsd", "http://www.xbrl.org/lrr/role/reference-2009-12-16.xsd", "http://xbrl.fasb.org/us-gaap/2019/elts/us-parts-codification-2019-01-31.xsd" ] } }, "elementCount": 605, "entityCount": 1, "hidden": { "http://fasb.org/us-gaap/2019-01-31": 14, "http://www.koppers.com/20200331": 12, "http://xbrl.sec.gov/dei/2019-01-31": 7, "total": 33 }, "keyCustom": 36, "keyStandard": 402, "memberCustom": 45, "memberStandard": 48, "nsprefix": "kop", "nsuri": "http://www.koppers.com/20200331", "report": { "R1": { "firstAnchor": { "ancestors": [ "p", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "dei:DocumentType", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "document", "isDefault": "true", "longName": "100000 - Document - Document and Entity Information", "role": "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation", "shortName": "Document and Entity Information", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "p", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "dei:DocumentType", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R10": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "kop:DiscontinuedOperationsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100090 - Disclosure - Discontinued Operations", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperations", "shortName": "Discontinued Operations", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "kop:DiscontinuedOperationsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R11": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:FairValueMeasurementInputsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100100 - Disclosure - Fair Value Measurements", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurements", "shortName": "Fair Value Measurements", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:FairValueMeasurementInputsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R12": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:StockholdersEquityNoteDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100110 - Disclosure - Comprehensive Income and Equity", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquity", "shortName": "Comprehensive Income and Equity", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:StockholdersEquityNoteDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R13": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:EarningsPerShareTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100120 - Disclosure - Earnings per Common Share", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShare", "shortName": "Earnings per Common Share", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:EarningsPerShareTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R14": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100130 - Disclosure - Stock-based Compensation", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensation", "shortName": "Stock-based Compensation", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R15": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:SegmentReportingDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100140 - Disclosure - Segment Information", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformation", "shortName": "Segment Information", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:SegmentReportingDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R16": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:IncomeTaxDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100150 - Disclosure - Income Taxes", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxes", "shortName": "Income Taxes", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:IncomeTaxDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R17": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:InventoryDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100160 - Disclosure - Inventories", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventories", "shortName": "Inventories", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:InventoryDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R18": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100170 - Disclosure - Property, Plant and Equipment", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipment", "shortName": "Property, Plant and Equipment", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R19": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100180 - Disclosure - Pensions and Post-Retirement Benefit Plans", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlans", "shortName": "Pensions and Post-Retirement Benefit Plans", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R2": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "statement", "isDefault": "false", "longName": "100010 - Statement - Condensed Consolidated Statement of Operations and Comprehensive Income (Unaudited)", "role": "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited", "shortName": "Condensed Consolidated Statement of Operations and Comprehensive Income (Unaudited)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "lang": null, "name": "us-gaap:CostOfGoodsAndServicesSold", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R20": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:DebtDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100190 - Disclosure - Debt", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebt", "shortName": "Debt", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:DebtDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R21": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:AssetRetirementObligationDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100200 - Disclosure - Asset Retirement Obligations", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligations", "shortName": "Asset Retirement Obligations", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:AssetRetirementObligationDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R22": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:LeasesOfLesseeDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100210 - Disclosure - Leases", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeases", "shortName": "Leases", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:LeasesOfLesseeDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R23": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100220 - Disclosure - Derivative Financial Instruments", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstruments", "shortName": "Derivative Financial Instruments", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R24": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100230 - Disclosure - Commitments and Contingent Liabilities", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilities", "shortName": "Commitments and Contingent Liabilities", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R25": { "firstAnchor": { "ancestors": [ "us-gaap:NewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100240 - Disclosure - New Accounting Pronouncements (Policies)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureNewAccountingPronouncementsPolicies", "shortName": "New Accounting Pronouncements (Policies)", "subGroupType": "policies", "uniqueAnchor": { "ancestors": [ "us-gaap:NewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R26": { "firstAnchor": { "ancestors": [ "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfRestructuringReserveByTypeOfCostTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100250 - Disclosure - Plant Closures and Divestitures (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresTables", "shortName": "Plant Closures and Divestitures (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfRestructuringReserveByTypeOfCostTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R27": { "firstAnchor": { "ancestors": [ "kop:DiscontinuedOperationsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "srt:ScheduleOfCondensedIncomeStatementTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100260 - Disclosure - Discontinued Operations (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsTables", "shortName": "Discontinued Operations (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "kop:DiscontinuedOperationsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "srt:ScheduleOfCondensedIncomeStatementTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R28": { "firstAnchor": { "ancestors": [ "us-gaap:FairValueMeasurementInputsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:FairValueByBalanceSheetGroupingTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100270 - Disclosure - Fair Value Measurements (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsTables", "shortName": "Fair Value Measurements (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "us-gaap:FairValueMeasurementInputsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:FairValueByBalanceSheetGroupingTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R29": { "firstAnchor": { "ancestors": [ "us-gaap:StockholdersEquityNoteDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfComprehensiveIncomeLossTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100280 - Disclosure - Comprehensive Income and Equity (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityTables", "shortName": "Comprehensive Income and Equity (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "us-gaap:StockholdersEquityNoteDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfComprehensiveIncomeLossTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R3": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "statement", "isDefault": "false", "longName": "100020 - Statement - Condensed Consolidated Statement of Operations and Comprehensive Income (Unaudited) (Parenthetical)", "role": "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnauditedParenthetical", "shortName": "Condensed Consolidated Statement of Operations and Comprehensive Income (Unaudited) (Parenthetical)", "subGroupType": "parenthetical", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R30": { "firstAnchor": { "ancestors": [ "us-gaap:EarningsPerShareTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100290 - Disclosure - Earnings per Common Share (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareTables", "shortName": "Earnings per Common Share (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "us-gaap:EarningsPerShareTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R31": { "firstAnchor": { "ancestors": [ "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100300 - Disclosure - Stock-based Compensation (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables", "shortName": "Stock-based Compensation (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R32": { "firstAnchor": { "ancestors": [ "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ReconciliationOfRevenueFromSegmentsToConsolidatedTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100310 - Disclosure - Segment Information (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationTables", "shortName": "Segment Information (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ReconciliationOfRevenueFromSegmentsToConsolidatedTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R33": { "firstAnchor": { "ancestors": [ "p", "us-gaap:IncomeTaxDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100320 - Disclosure - Income Taxes (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesTables", "shortName": "Income Taxes (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "p", "us-gaap:IncomeTaxDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R34": { "firstAnchor": { "ancestors": [ "us-gaap:InventoryDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfInventoryCurrentTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100330 - Disclosure - Inventories (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesTables", "shortName": "Inventories (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "us-gaap:InventoryDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfInventoryCurrentTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R35": { "firstAnchor": { "ancestors": [ "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:PropertyPlantAndEquipmentTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100340 - Disclosure - Property, Plant and Equipment (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentTables", "shortName": "Property, Plant and Equipment (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:PropertyPlantAndEquipmentTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R36": { "firstAnchor": { "ancestors": [ "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100350 - Disclosure - Pensions and Post-Retirement Benefit Plans (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansTables", "shortName": "Pensions and Post-Retirement Benefit Plans (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R37": { "firstAnchor": { "ancestors": [ "us-gaap:DebtDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfDebtInstrumentsTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100360 - Disclosure - Debt (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtTables", "shortName": "Debt (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "us-gaap:DebtDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfDebtInstrumentsTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R38": { "firstAnchor": { "ancestors": [ "p", "us-gaap:AssetRetirementObligationDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfChangeInAssetRetirementObligationTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100370 - Disclosure - Asset Retirement Obligations (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligationsTables", "shortName": "Asset Retirement Obligations (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "p", "us-gaap:AssetRetirementObligationDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfChangeInAssetRetirementObligationTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R39": { "firstAnchor": { "ancestors": [ "us-gaap:LeasesOfLesseeDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100380 - Disclosure - Leases (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesTables", "shortName": "Leases (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "us-gaap:LeasesOfLesseeDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R4": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:CashAndCashEquivalentsAtCarryingValue", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "statement", "isDefault": "false", "longName": "100030 - Statement - Condensed Consolidated Balance Sheet", "role": "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet", "shortName": "Condensed Consolidated Balance Sheet", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "lang": null, "name": "us-gaap:AccountsReceivableNetCurrent", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R40": { "firstAnchor": { "ancestors": [ "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100390 - Disclosure - Derivative Financial Instruments (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsTables", "shortName": "Derivative Financial Instruments (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R41": { "firstAnchor": { "ancestors": [ "span", "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100400 - Disclosure - Commitments and Contingent Liabilities (Tables)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesTables", "shortName": "Commitments and Contingent Liabilities (Tables)", "subGroupType": "tables", "uniqueAnchor": { "ancestors": [ "span", "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R42": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_srtStatementGeographicalAxis_countryCN_us-gaapDisposalGroupClassificationAxis_us-gaapDiscontinuedOperationsDisposedOfByMeansOtherThanSaleMember_us-gaapIncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_kopCarbonMaterialsAndChemicalsMember_20160331", "decimals": "INF", "first": true, "lang": null, "name": "kop:PercentageOfOwnershipInterest", "reportCount": 1, "unique": true, "unitRef": "U_xbrlipure", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100410 - Disclosure - Plant Closures and Divestitures - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail", "shortName": "Plant Closures and Divestitures - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_srtStatementGeographicalAxis_countryCN_us-gaapDisposalGroupClassificationAxis_us-gaapDiscontinuedOperationsDisposedOfByMeansOtherThanSaleMember_us-gaapIncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_kopCarbonMaterialsAndChemicalsMember_20160331", "decimals": "INF", "first": true, "lang": null, "name": "kop:PercentageOfOwnershipInterest", "reportCount": 1, "unique": true, "unitRef": "U_xbrlipure", "xsiNil": "false" } }, "R43": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfRestructuringReserveByTypeOfCostTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20191231", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:RestructuringReserve", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100420 - Disclosure - Plant Closures and Divestitures - Summary of Restructuring Activities and Related Reserves (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail", "shortName": "Plant Closures and Divestitures - Summary of Restructuring Activities and Related Reserves (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfRestructuringReserveByTypeOfCostTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20181231", "decimals": "-5", "lang": null, "name": "us-gaap:RestructuringReserve", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R44": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "srt:ScheduleOfCondensedCashFlowStatementTableTextBlock", "kop:DiscontinuedOperationsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:NetCashProvidedByUsedInDiscontinuedOperations", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100430 - Disclosure - Discontinued Operations - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "shortName": "Discontinued Operations - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "kop:DiscontinuedOperationsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-6", "lang": null, "name": "us-gaap:AssetImpairmentCharges", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R45": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "srt:ScheduleOfCondensedIncomeStatementTableTextBlock", "kop:DiscontinuedOperationsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100440 - Disclosure - Discontinued Operations - Schedule of Net Sales and Operating Loss Profit from Discontinued Operations (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetSalesAndOperatingLossProfitFromDiscontinuedOperationsDetail", "shortName": "Discontinued Operations - Schedule of Net Sales and Operating Loss Profit from Discontinued Operations (Detail)", "subGroupType": "details", "uniqueAnchor": null }, "R46": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "srt:ScheduleOfCondensedCashFlowStatementTableTextBlock", "kop:DiscontinuedOperationsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100450 - Disclosure - Discontinued Operations - Schedule of Net cash Inflows and Outflows From Discontinued Operations (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail", "shortName": "Discontinued Operations - Schedule of Net cash Inflows and Outflows From Discontinued Operations (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "srt:ScheduleOfCondensedCashFlowStatementTableTextBlock", "kop:DiscontinuedOperationsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R47": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "srt:ScheduleOfCondensedBalanceSheetTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100460 - Disclosure - Discontinued Operations - Schedule of Carrying Amount of Assets and Liabilities by Major Class Classified as Held for Sale (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail", "shortName": "Discontinued Operations - Schedule of Carrying Amount of Assets and Liabilities by Major Class Classified as Held for Sale (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "srt:ScheduleOfCondensedBalanceSheetTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R48": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:FairValueByBalanceSheetGroupingTextBlock", "us-gaap:FairValueMeasurementInputsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFairValueByMeasurementBasisAxis_us-gaapEstimateOfFairValueFairValueDisclosureMember_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:CashAndCashEquivalentsFairValueDisclosure", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100470 - Disclosure - Fair Value Measurements - Schedule of Company's Financial Instruments (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail", "shortName": "Fair Value Measurements - Schedule of Company's Financial Instruments (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:FairValueByBalanceSheetGroupingTextBlock", "us-gaap:FairValueMeasurementInputsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFairValueByMeasurementBasisAxis_us-gaapEstimateOfFairValueFairValueDisclosureMember_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:CashAndCashEquivalentsFairValueDisclosure", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R49": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:ProfitLoss", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100480 - Disclosure - Comprehensive Income and Equity - Schedule of Comprehensive Income (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail", "shortName": "Comprehensive Income and Equity - Schedule of Comprehensive Income (Detail)", "subGroupType": "details", "uniqueAnchor": null }, "R5": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "statement", "isDefault": "false", "longName": "100040 - Statement - Condensed Consolidated Balance Sheet (Parenthetical)", "role": "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetParenthetical", "shortName": "Condensed Consolidated Balance Sheet (Parenthetical)", "subGroupType": "parenthetical", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R50": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfComprehensiveIncomeLossTableTextBlock", "us-gaap:StockholdersEquityNoteDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100490 - Disclosure - Comprehensive Income and Equity - Schedule of Comprehensive Income (Parenthetical) (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeParentheticalDetail", "shortName": "Comprehensive Income and Equity - Schedule of Comprehensive Income (Parenthetical) (Detail)", "subGroupType": "parenthetical", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfComprehensiveIncomeLossTableTextBlock", "us-gaap:StockholdersEquityNoteDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R51": { "firstAnchor": { "ancestors": [ "p", "us-gaap:StockholdersEquityNoteDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100500 - Disclosure - Comprehensive Income and Equity - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityAdditionalInformationDetail", "shortName": "Comprehensive Income and Equity - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "us-gaap:StockholdersEquityNoteDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R52": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20191231", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100510 - Disclosure - Comprehensive Income and Equity - Schedule of Change in Equity (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail", "shortName": "Comprehensive Income and Equity - Schedule of Change in Equity (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20181231", "decimals": "-5", "lang": null, "name": "us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R53": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:NetIncomeLoss", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100520 - Disclosure - Earnings per Common Share - Schedule of Computation of Basic and Diluted Earnings per Common Share (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail", "shortName": "Earnings per Common Share - Schedule of Computation of Basic and Diluted Earnings per Common Share (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock", "us-gaap:EarningsPerShareTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "lang": null, "name": "us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R54": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNonvestedShareActivityTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "INF", "first": true, "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber", "reportCount": 1, "unitRef": "U_xbrlishares", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100530 - Disclosure - Stock-based Compensation - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "shortName": "Stock-based Compensation - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "span", "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20190331", "decimals": "-5", "lang": null, "name": "us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R55": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapAwardDateAxis_kopMarchTwoThousandTwentyGrantMember_20200331", "decimals": "2", "first": true, "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice", "reportCount": 1, "unitRef": "U_iso4217USD_xbrlishares", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100540 - Disclosure - Stock-based Compensation - Performance Award Fair Value Assumptions (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "shortName": "Stock-based Compensation - Performance Award Fair Value Assumptions (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapAwardDateAxis_kopMarchTwoThousandTwentyGrantMember_us-gaapAwardTypeAxis_us-gaapPerformanceSharesMember_20200331", "decimals": "INF", "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD_xbrlishares", "xsiNil": "false" } }, "R56": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNonvestedShareActivityTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "INF", "first": true, "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber", "reportCount": 1, "unitRef": "U_xbrlishares", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100550 - Disclosure - Stock-based Compensation - Summary of Performance Stock Units (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail", "shortName": "Stock-based Compensation - Summary of Performance Stock Units (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_srtRangeAxis_srtMinimumMember_us-gaapAwardDateAxis_kopTwoThousandEighteenThroughTwoThousandTwentyMember_us-gaapAwardTypeAxis_us-gaapPerformanceSharesMember_20200331", "decimals": "INF", "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber", "reportCount": 1, "unique": true, "unitRef": "U_xbrlishares", "xsiNil": "false" } }, "R57": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNonvestedShareActivityTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20191231", "decimals": "INF", "first": true, "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber", "reportCount": 1, "unitRef": "U_xbrlishares", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100560 - Disclosure - Stock-based Compensation - Summary of Status and Activity of Non-Vested Stock Units (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail", "shortName": "Stock-based Compensation - Summary of Status and Activity of Non-Vested Stock Units (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNonvestedShareActivityTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "INF", "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod", "reportCount": 1, "unique": true, "unitRef": "U_xbrlishares", "xsiNil": "false" } }, "R58": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapAwardDateAxis_kopMarchTwoThousandTwentyGrantMember_20200331", "decimals": "2", "first": true, "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice", "reportCount": 1, "unitRef": "U_iso4217USD_xbrlishares", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100570 - Disclosure - Stock-based Compensation - Stock Options Fair Value Assumptions (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail", "shortName": "Stock-based Compensation - Stock Options Fair Value Assumptions (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapAwardDateAxis_kopMarchTwoThousandSeventeenGrantMember_20200331", "decimals": "2", "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD_xbrlishares", "xsiNil": "false" } }, "R59": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20191231", "decimals": "INF", "first": true, "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber", "reportCount": 1, "unique": true, "unitRef": "U_xbrlishares", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100580 - Disclosure - Stock-based Compensation - Summary of Status and Activity of Stock Options (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail", "shortName": "Stock-based Compensation - Summary of Status and Activity of Stock Options (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20191231", "decimals": "INF", "first": true, "lang": null, "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber", "reportCount": 1, "unique": true, "unitRef": "U_xbrlishares", "xsiNil": "false" } }, "R6": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:ProfitLoss", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "statement", "isDefault": "false", "longName": "100050 - Statement - Condensed Consolidated Statement of Cash Flows (Unaudited)", "role": "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited", "shortName": "Condensed Consolidated Statement of Cash Flows (Unaudited)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "lang": null, "name": "kop:DepreciationAndAmortization1", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R60": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100590 - Disclosure - Stock-based Compensation - Schedule of Stock-Based Compensation Expense Recognized (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail", "shortName": "Stock-based Compensation - Schedule of Stock-Based Compensation Expense Recognized (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R61": { "firstAnchor": { "ancestors": [ "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "INF", "first": true, "lang": null, "name": "us-gaap:NumberOfReportableSegments", "reportCount": 1, "unique": true, "unitRef": "U_kopSegment", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100600 - Disclosure - Segment Information - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail", "shortName": "Segment Information - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "INF", "first": true, "lang": null, "name": "us-gaap:NumberOfReportableSegments", "reportCount": 1, "unique": true, "unitRef": "U_kopSegment", "xsiNil": "false" } }, "R62": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100610 - Disclosure - Segment Information - Summary of Results of Segment Operations (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "shortName": "Segment Information - Summary of Results of Segment Operations (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_srtConsolidationItemsAxis_us-gaapOperatingSegmentsMember_us-gaapStatementBusinessSegmentsAxis_kopRailroadAndUtilityProductsAndServicesMember_20200101_20200331", "decimals": "-5", "lang": null, "name": "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R63": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "srt:ScheduleOfCondensedIncomeStatementTableTextBlock", "kop:DiscontinuedOperationsDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100620 - Disclosure - Segment Information - Summary of Results of Segment Operations (Parenthetical) (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsParentheticalDetail", "shortName": "Segment Information - Summary of Results of Segment Operations (Parenthetical) (Detail)", "subGroupType": "parenthetical", "uniqueAnchor": { "ancestors": [ "us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization", "link:footnote", "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "lang": "en-US", "name": "us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R64": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100630 - Disclosure - Segment Information - Schedule of Segment Revenues for Significant Product Lines (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail", "shortName": "Segment Information - Schedule of Segment Revenues for Significant Product Lines (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_srtProductOrServiceAxis_kopRailroadTreatedProductsMember_us-gaapStatementBusinessSegmentsAxis_kopRailroadAndUtilityProductsAndServicesMember_20200101_20200331", "decimals": "-5", "lang": null, "name": "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R65": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:Assets", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100640 - Disclosure - Segment Information - Summary of Tangible and Intangible Assets by Segments (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail", "shortName": "Segment Information - Summary of Tangible and Intangible Assets by Segments (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_srtConsolidationItemsAxis_us-gaapOperatingSegmentsMember_us-gaapStatementBusinessSegmentsAxis_kopRailroadAndUtilityProductsAndServicesMember_20200331", "decimals": "-5", "lang": null, "name": "us-gaap:Assets", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R66": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "srt:ScheduleOfCondensedBalanceSheetTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperation", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100650 - Disclosure - Segment Information - Summary of Tangible and Intangible Assets by Segments ((Parenthetical)) (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail", "shortName": "Segment Information - Summary of Tangible and Intangible Assets by Segments ((Parenthetical)) (Detail)", "subGroupType": "parenthetical", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "link:footnote", "us-gaap:ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapDisposalGroupClassificationAxis_us-gaapDiscontinuedOperationsHeldforsaleMember_us-gaapStatementBusinessSegmentsAxis_kopCarbonMaterialsAndChemicalsMember_20200331", "decimals": "-5", "lang": "en-US", "name": "us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperation", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R67": { "firstAnchor": { "ancestors": [ "p", "us-gaap:IncomeTaxDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "3", "first": true, "lang": null, "name": "us-gaap:EffectiveIncomeTaxRateContinuingOperations", "reportCount": 1, "unitRef": "U_xbrlipure", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100660 - Disclosure - Income Taxes - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail", "shortName": "Income Taxes - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "span", "p", "us-gaap:IncomeTaxDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "2", "lang": null, "name": "kop:PercentageOfAllowableBusinessInterestExpenseDeductionFromAdjustedTaxableIncome", "reportCount": 1, "unique": true, "unitRef": "U_xbrlipure", "xsiNil": "false" } }, "R68": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "us-gaap:IncomeTaxDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "INF", "first": true, "lang": null, "name": "us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate", "reportCount": 1, "unique": true, "unitRef": "U_xbrlipure", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100670 - Disclosure - Income Taxes - Summary of Income Taxes Reconciled with Federal Statutory Rate (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail", "shortName": "Income Taxes - Summary of Income Taxes Reconciled with Federal Statutory Rate (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "us-gaap:IncomeTaxDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "INF", "first": true, "lang": null, "name": "us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate", "reportCount": 1, "unique": true, "unitRef": "U_xbrlipure", "xsiNil": "false" } }, "R69": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfInventoryCurrentTableTextBlock", "us-gaap:InventoryDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:InventoryRawMaterials", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100680 - Disclosure - Inventories - Components of Net Inventories (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail", "shortName": "Inventories - Components of Net Inventories (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfInventoryCurrentTableTextBlock", "us-gaap:InventoryDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:InventoryRawMaterials", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R7": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100060 - Disclosure - Basis of Presentation", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureBasisOfPresentation", "shortName": "Basis of Presentation", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R70": { "firstAnchor": { "ancestors": [ "link:footnote", "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfInventoryCurrentTableTextBlock", "us-gaap:InventoryDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_srtScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_kopKoppersJiangsuCarbonChemicalCompanyLimitedMember_20200331", "decimals": "-5", "first": true, "lang": "en-US", "name": "kop:AssetsHeldForSaleDiscontinuedOperations", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100690 - Disclosure - Inventories - Components of Net Inventories (Parenthetical) (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesParentheticalDetail", "shortName": "Inventories - Components of Net Inventories (Parenthetical) (Detail)", "subGroupType": "parenthetical", "uniqueAnchor": { "ancestors": [ "link:footnote", "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfInventoryCurrentTableTextBlock", "us-gaap:InventoryDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_srtScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_kopKoppersJiangsuCarbonChemicalCompanyLimitedMember_20200331", "decimals": "-5", "first": true, "lang": "en-US", "name": "kop:AssetsHeldForSaleDiscontinuedOperations", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R71": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:PropertyPlantAndEquipmentTextBlock", "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:PropertyPlantAndEquipmentGross", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100700 - Disclosure - Property, Plant and Equipment - Property, Plant and Equipment (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail", "shortName": "Property, Plant and Equipment - Property, Plant and Equipment (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:PropertyPlantAndEquipmentTextBlock", "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:PropertyPlantAndEquipmentGross", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R72": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "srt:ScheduleOfCondensedBalanceSheetTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperation", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100710 - Disclosure - Property, Plant and Equipment - Property, Plant and Equipment (Parenthetical) (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentParentheticalDetail", "shortName": "Property, Plant and Equipment - Property, Plant and Equipment (Parenthetical) (Detail)", "subGroupType": "parenthetical", "uniqueAnchor": { "ancestors": [ "link:footnote", "p", "td", "tr", "table", "div", "us-gaap:PropertyPlantAndEquipmentTextBlock", "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_srtScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_kopKoppersJiangsuCarbonChemicalCompanyLimitedMember_20200331", "decimals": "-5", "lang": "en-US", "name": "us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperation", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R73": { "firstAnchor": { "ancestors": [ "span", "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "INF", "first": true, "lang": null, "name": "kop:NumberOfNonQualifiedDefinedBenefitPensionPlans", "reportCount": 1, "unique": true, "unitRef": "U_kopPlan", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100720 - Disclosure - Pensions and Post-Retirement Benefit Plans - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansAdditionalInformationDetail", "shortName": "Pensions and Post-Retirement Benefit Plans - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "span", "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "INF", "first": true, "lang": null, "name": "kop:NumberOfNonQualifiedDefinedBenefitPensionPlans", "reportCount": 1, "unique": true, "unitRef": "U_kopPlan", "xsiNil": "false" } }, "R74": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DefinedBenefitPlanServiceCost", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100730 - Disclosure - Pensions and Post-Retirement Benefit Plans - Components of Net Periodic Benefit Cost for Pension Plans (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail", "shortName": "Pensions and Post-Retirement Benefit Plans - Components of Net Periodic Benefit Cost for Pension Plans (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DefinedBenefitPlanServiceCost", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R75": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfDebtInstrumentsTextBlock", "us-gaap:DebtDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:LongTermDebt", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100740 - Disclosure - Debt - Schedule of Long-Term Debt Instruments (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail", "shortName": "Debt - Schedule of Long-Term Debt Instruments (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfDebtInstrumentsTextBlock", "us-gaap:DebtDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:LongTermDebt", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R76": { "firstAnchor": { "ancestors": [ "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapDebtInstrumentAxis_kopSeniorSecuredCreditFacilitiesMember_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:LettersOfCreditOutstandingAmount", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100750 - Disclosure - Debt - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "shortName": "Debt - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapDebtInstrumentAxis_kopSeniorSecuredCreditFacilitiesMember_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:LettersOfCreditOutstandingAmount", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R77": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "us-gaap:AssetRetirementObligationDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20191231", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:AssetRetirementObligation", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100760 - Disclosure - Asset Retirement Obligations - Schedule of Changes in Carrying Values of Asset Retirement Obligations (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligationsScheduleOfChangesInCarryingValuesOfAssetRetirementObligationsDetail", "shortName": "Asset Retirement Obligations - Schedule of Changes in Carrying Values of Asset Retirement Obligations (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "us-gaap:AssetRetirementObligationDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20181231", "decimals": "-5", "lang": null, "name": "us-gaap:AssetRetirementObligation", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R78": { "firstAnchor": { "ancestors": [ "p", "us-gaap:LeasesOfLesseeDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:OperatingLeaseCost", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100770 - Disclosure - Leases - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesAdditionalInformationDetail", "shortName": "Leases - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "us-gaap:LeasesOfLesseeDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:OperatingLeaseCost", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R79": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100780 - Disclosure - Leases - Summary of Amount and Timing of Cash Flows From Operating Leases (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail", "shortName": "Leases - Summary of Amount and Timing of Cash Flows From Operating Leases (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R8": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:NewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100070 - Disclosure - New Accounting Pronouncements", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureNewAccountingPronouncements", "shortName": "New Accounting Pronouncements", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:NewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R80": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:OperatingLeaseRightOfUseAsset", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100800 - Disclosure - Leases - Schedule of Supplemental Consolidated Balance Sheet Information Related to Leases (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail", "shortName": "Leases - Schedule of Supplemental Consolidated Balance Sheet Information Related to Leases (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "kop:LeasesSupplementalConsolidatedBalanceSheetInformationTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20190331", "decimals": "-5", "lang": null, "name": "us-gaap:OperatingLeaseRightOfUseAsset", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R81": { "firstAnchor": { "ancestors": [ "p", "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:MaximumLengthOfTimeHedgedInCashFlowHedge1", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100810 - Disclosure - Derivative Financial Instruments - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsAdditionalInformationDetail", "shortName": "Derivative Financial Instruments - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:MaximumLengthOfTimeHedgedInCashFlowHedge1", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R82": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFinancialInstrumentAxis_us-gaapSwapMember_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DerivativeLiabilityNotionalAmount", "reportCount": 1, "unique": true, "unitRef": "U_iso4217GBP", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100820 - Disclosure - Derivative Financial Instruments - Schedule of Outstanding Copper Swap Contracts (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail", "shortName": "Derivative Financial Instruments - Schedule of Outstanding Copper Swap Contracts (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFinancialInstrumentAxis_us-gaapSwapMember_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DerivativeLiabilityNotionalAmount", "reportCount": 1, "unique": true, "unitRef": "U_iso4217GBP", "xsiNil": "false" } }, "R83": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFinancialInstrumentAxis_us-gaapSwapMember_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DerivativeFairValueOfDerivativeNet", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100830 - Disclosure - Derivative Financial Instruments - Schedule of Fair Value of Outstanding Copper Swap Contracts Recorded in Balance Sheet (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "shortName": "Derivative Financial Instruments - Schedule of Fair Value of Outstanding Copper Swap Contracts Recorded in Balance Sheet (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFinancialInstrumentAxis_us-gaapSwapMember_20200101_20200331", "decimals": "-5", "lang": null, "name": "us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R84": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFinancialInstrumentAxis_kopHedgesMember_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100840 - Disclosure - Derivative Financial Instruments - Schedule of (Loss) Gain from Contract Not Designated as Hedges (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfLossGainFromContractNotDesignatedAsHedgesDetail", "shortName": "Derivative Financial Instruments - Schedule of (Loss) Gain from Contract Not Designated as Hedges (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFinancialInstrumentAxis_kopHedgesMember_20200101_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R85": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFinancialInstrumentAxis_us-gaapForwardContractsMember_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100850 - Disclosure - Derivative Financial Instruments - Schedule of Fair Value of Outstanding Foreign Currency Forward Contracts (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail", "shortName": "Derivative Financial Instruments - Schedule of Fair Value of Outstanding Foreign Currency Forward Contracts (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "us-gaap:ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_us-gaapFinancialInstrumentAxis_us-gaapForwardContractsMember_20200331", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R86": { "firstAnchor": null, "groupType": "disclosure", "isDefault": "false", "longName": "100860 - Disclosure - Derivative Financial Instruments - Summary of Net Currency Units Outstanding (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsSummaryOfNetCurrencyUnitsOutstandingDetail", "shortName": "Derivative Financial Instruments - Summary of Net Currency Units Outstanding (Detail)", "subGroupType": "details", "uniqueAnchor": null }, "R87": { "firstAnchor": { "ancestors": [ "span", "p", "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "INF", "first": true, "lang": null, "name": "kop:LossContingencyNumberOfStatesNewClaimsFiled", "reportCount": 1, "unique": true, "unitRef": "U_kopState", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100870 - Disclosure - Commitments and Contingent Liabilities - Additional Information (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail", "shortName": "Commitments and Contingent Liabilities - Additional Information (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "span", "p", "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "INF", "first": true, "lang": null, "name": "kop:LossContingencyNumberOfStatesNewClaimsFiled", "reportCount": 1, "unique": true, "unitRef": "U_kopState", "xsiNil": "false" } }, "R88": { "firstAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20191231", "decimals": "-5", "first": true, "lang": null, "name": "us-gaap:AccrualForEnvironmentalLossContingencies", "reportCount": 1, "unitRef": "U_iso4217USD", "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100880 - Disclosure - Commitments and Contingent Liabilities - Changes in Accrued Liability for Environmental Matters (Detail)", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesChangesInAccruedLiabilityForEnvironmentalMattersDetail", "shortName": "Commitments and Contingent Liabilities - Changes in Accrued Liability for Environmental Matters (Detail)", "subGroupType": "details", "uniqueAnchor": { "ancestors": [ "p", "td", "tr", "table", "div", "ix:continuation", "ix:continuation", "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": "-5", "lang": null, "name": "us-gaap:AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses", "reportCount": 1, "unique": true, "unitRef": "U_iso4217USD", "xsiNil": "false" } }, "R9": { "firstAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "100080 - Disclosure - Plant Closures and Divestitures", "role": "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestitures", "shortName": "Plant Closures and Divestitures", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "body", "html" ], "baseRef": "kop-10q_20200331.htm", "contextRef": "C_0001315257_20200101_20200331", "decimals": null, "first": true, "lang": "en-US", "name": "us-gaap:DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } } }, "segmentCount": 95, "tag": { "country_AU": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "AUSTRALIA", "terseLabel": "Australia [Member]" } } }, "localname": "AU", "nsuri": "http://xbrl.sec.gov/country/2017-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "country_CN": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "CHINA", "terseLabel": "China [Member]" } } }, "localname": "CN", "nsuri": "http://xbrl.sec.gov/country/2017-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "country_US": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "UNITED STATES", "terseLabel": "United States [Member]" } } }, "localname": "US", "nsuri": "http://xbrl.sec.gov/country/2017-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "dei_AmendmentFlag": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.", "label": "Amendment Flag", "terseLabel": "Amendment Flag" } } }, "localname": "AmendmentFlag", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "booleanItemType" }, "dei_CityAreaCode": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Area code of city", "label": "City Area Code", "terseLabel": "City Area Code" } } }, "localname": "CityAreaCode", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "normalizedStringItemType" }, "dei_CoverAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Cover page.", "label": "Cover [Abstract]" } } }, "localname": "CoverAbstract", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "xbrltype": "stringItemType" }, "dei_CurrentFiscalYearEndDate": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "End date of current fiscal year in the format --MM-DD.", "label": "Current Fiscal Year End Date", "terseLabel": "Current Fiscal Year End Date" } } }, "localname": "CurrentFiscalYearEndDate", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "gMonthDayItemType" }, "dei_DocumentFiscalPeriodFocus": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Fiscal period values are FY, Q1, Q2, and Q3. 1st, 2nd and 3rd quarter 10-Q or 10-QT statements have value Q1, Q2, and Q3 respectively, with 10-K, 10-KT or other fiscal year statements having FY.", "label": "Document Fiscal Period Focus", "terseLabel": "Document Fiscal Period Focus" } } }, "localname": "DocumentFiscalPeriodFocus", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "fiscalPeriodItemType" }, "dei_DocumentFiscalYearFocus": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "This is focus fiscal year of the document report in CCYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006.", "label": "Document Fiscal Year Focus", "terseLabel": "Document Fiscal Year Focus" } } }, "localname": "DocumentFiscalYearFocus", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "gYearItemType" }, "dei_DocumentPeriodEndDate": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.", "label": "Document Period End Date", "terseLabel": "Document Period End Date" } } }, "localname": "DocumentPeriodEndDate", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "dateItemType" }, "dei_DocumentQuarterlyReport": { "auth_ref": [ "r449" ], "lang": { "en-US": { "role": { "documentation": "Boolean flag that is true only for a form used as an quarterly report.", "label": "Document Quarterly Report", "terseLabel": "Document Quarterly Report" } } }, "localname": "DocumentQuarterlyReport", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "booleanItemType" }, "dei_DocumentTransitionReport": { "auth_ref": [ "r450" ], "lang": { "en-US": { "role": { "documentation": "Boolean flag that is true only for a form used as a transition report.", "label": "Document Transition Report", "terseLabel": "Document Transition Report" } } }, "localname": "DocumentTransitionReport", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "booleanItemType" }, "dei_DocumentType": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.", "label": "Document Type", "terseLabel": "Document Type" } } }, "localname": "DocumentType", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "submissionTypeItemType" }, "dei_EntityAddressAddressLine1": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Address Line 1 such as Attn, Building Name, Street Name", "label": "Entity Address Address Line1", "terseLabel": "Entity Address, Address Line One" } } }, "localname": "EntityAddressAddressLine1", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "normalizedStringItemType" }, "dei_EntityAddressCityOrTown": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Name of the City or Town", "label": "Entity Address City Or Town", "terseLabel": "Entity Address, City or Town" } } }, "localname": "EntityAddressCityOrTown", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "normalizedStringItemType" }, "dei_EntityAddressPostalZipCode": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Code for the postal or zip code", "label": "Entity Address Postal Zip Code", "terseLabel": "Entity Address, Postal Zip Code" } } }, "localname": "EntityAddressPostalZipCode", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "normalizedStringItemType" }, "dei_EntityAddressStateOrProvince": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Name of the state or province.", "label": "Entity Address State Or Province", "terseLabel": "Entity Address, State or Province" } } }, "localname": "EntityAddressStateOrProvince", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "stateOrProvinceItemType" }, "dei_EntityCentralIndexKey": { "auth_ref": [ "r451" ], "lang": { "en-US": { "role": { "documentation": "A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.", "label": "Entity Central Index Key", "terseLabel": "Entity Central Index Key" } } }, "localname": "EntityCentralIndexKey", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "centralIndexKeyItemType" }, "dei_EntityCommonStockSharesOutstanding": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report. Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument.", "label": "Entity Common Stock Shares Outstanding", "terseLabel": "Entity Common Stock, Shares Outstanding" } } }, "localname": "EntityCommonStockSharesOutstanding", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "sharesItemType" }, "dei_EntityCurrentReportingStatus": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Indicate 'Yes' or 'No' whether registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. This information should be based on the registrant's current or most recent filing containing the related disclosure.", "label": "Entity Current Reporting Status", "terseLabel": "Entity Current Reporting Status" } } }, "localname": "EntityCurrentReportingStatus", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "yesNoItemType" }, "dei_EntityDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "All the names of the entities being reported upon in a document. Any legal structure used to conduct activities or to hold assets. Some examples of such structures are corporations, partnerships, limited liability companies, grantor trusts, and other trusts. This item does not include business and geographical segments which are included in the geographical or business segments domains.", "label": "Entity [Domain]", "terseLabel": "Entity" } } }, "localname": "EntityDomain", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "dei_EntityEmergingGrowthCompany": { "auth_ref": [ "r451" ], "lang": { "en-US": { "role": { "documentation": "Indicate if registrant meets the emerging growth company criteria.", "label": "Entity Emerging Growth Company", "terseLabel": "Entity Emerging Growth Company" } } }, "localname": "EntityEmergingGrowthCompany", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "booleanItemType" }, "dei_EntityFileNumber": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.", "label": "Entity File Number", "terseLabel": "Entity File Number" } } }, "localname": "EntityFileNumber", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "fileNumberItemType" }, "dei_EntityFilerCategory": { "auth_ref": [ "r451" ], "lang": { "en-US": { "role": { "documentation": "Indicate whether the registrant is one of the following: Large Accelerated Filer, Accelerated Filer, Non-accelerated Filer. Definitions of these categories are stated in Rule 12b-2 of the Exchange Act. This information should be based on the registrant's current or most recent filing containing the related disclosure.", "label": "Entity Filer Category", "terseLabel": "Entity Filer Category" } } }, "localname": "EntityFilerCategory", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "filerCategoryItemType" }, "dei_EntityIncorporationStateCountryCode": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Two-character EDGAR code representing the state or country of incorporation.", "label": "Entity Incorporation State Country Code", "terseLabel": "Entity Incorporation, State or Country Code" } } }, "localname": "EntityIncorporationStateCountryCode", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "edgarStateCountryItemType" }, "dei_EntityInteractiveDataCurrent": { "auth_ref": [ "r452" ], "lang": { "en-US": { "role": { "documentation": "Boolean flag that is true when the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).", "label": "Entity Interactive Data Current", "terseLabel": "Entity Interactive Data Current" } } }, "localname": "EntityInteractiveDataCurrent", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "yesNoItemType" }, "dei_EntityRegistrantName": { "auth_ref": [ "r451" ], "lang": { "en-US": { "role": { "documentation": "The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.", "label": "Entity Registrant Name", "terseLabel": "Entity Registrant Name" } } }, "localname": "EntityRegistrantName", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "normalizedStringItemType" }, "dei_EntityShellCompany": { "auth_ref": [ "r451" ], "lang": { "en-US": { "role": { "documentation": "Boolean flag that is true when the registrant is a shell company as defined in Rule 12b-2 of the Exchange Act.", "label": "Entity Shell Company", "terseLabel": "Entity Shell Company" } } }, "localname": "EntityShellCompany", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "booleanItemType" }, "dei_EntitySmallBusiness": { "auth_ref": [ "r451" ], "lang": { "en-US": { "role": { "documentation": "Indicates that the company is a Smaller Reporting Company (SRC).", "label": "Entity Small Business", "terseLabel": "Entity Small Business" } } }, "localname": "EntitySmallBusiness", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "booleanItemType" }, "dei_EntityTaxIdentificationNumber": { "auth_ref": [ "r451" ], "lang": { "en-US": { "role": { "documentation": "The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.", "label": "Entity Tax Identification Number", "terseLabel": "Entity Tax Identification Number" } } }, "localname": "EntityTaxIdentificationNumber", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "employerIdItemType" }, "dei_LegalEntityAxis": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "The set of legal entities associated with a report.", "label": "Legal Entity [Axis]", "terseLabel": "Legal Entity" } } }, "localname": "LegalEntityAxis", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "dei_LocalPhoneNumber": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Local phone number for entity.", "label": "Local Phone Number", "terseLabel": "Local Phone Number" } } }, "localname": "LocalPhoneNumber", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "normalizedStringItemType" }, "dei_Security12bTitle": { "auth_ref": [ "r447" ], "lang": { "en-US": { "role": { "documentation": "Title of a 12(b) registered security.", "label": "Security12b Title", "terseLabel": "Title of 12(b) Security" } } }, "localname": "Security12bTitle", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "securityTitleItemType" }, "dei_SecurityExchangeName": { "auth_ref": [ "r448" ], "lang": { "en-US": { "role": { "documentation": "Name of the Exchange on which a security is registered.", "label": "Security Exchange Name", "terseLabel": "Security Exchange Name" } } }, "localname": "SecurityExchangeName", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "edgarExchangeCodeItemType" }, "dei_TradingSymbol": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Trading symbol of an instrument as listed on an exchange.", "label": "Trading Symbol", "terseLabel": "Trading Symbol" } } }, "localname": "TradingSymbol", "nsuri": "http://xbrl.sec.gov/dei/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation" ], "xbrltype": "tradingSymbolItemType" }, "kop_AccruedLiabilitiesCaptionMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Primary financial statement caption encompassing accrued liabilities.", "label": "Accrued Liabilities Caption [Member]", "terseLabel": "Accrued Liabilities [Member]" } } }, "localname": "AccruedLiabilitiesCaptionMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail" ], "xbrltype": "domainItemType" }, "kop_AggregateDivestitureCost": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Aggregate divestiture cost.", "label": "Aggregate Divestiture Cost", "terseLabel": "Aggregate disvestiture cost" } } }, "localname": "AggregateDivestitureCost", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "kop_AssetsHeldForSaleDiscontinuedOperations": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Assets held for sale discontinued operations.", "label": "Assets Held For Sale Discontinued Operations", "terseLabel": "Discontinued operations assets held for sale" } } }, "localname": "AssetsHeldForSaleDiscontinuedOperations", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesParentheticalDetail" ], "xbrltype": "monetaryItemType" }, "kop_BeazerEastMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Beazer east.", "label": "Beazer East [Member]", "terseLabel": "Beazer East [Member]" } } }, "localname": "BeazerEastMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_CarbonMaterialsAndChemicalsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Carbon materials and chemicals.", "label": "Carbon Materials And Chemicals [Member]", "terseLabel": "Carbon Materials and Chemicals [Member]" } } }, "localname": "CarbonMaterialsAndChemicalsMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail" ], "xbrltype": "domainItemType" }, "kop_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Cash paid for amounts included in measurement of lease liabilities.", "label": "Cash Paid For Amounts Included In Measurement Of Lease Liabilities [Abstract]", "terseLabel": "Cash paid for amounts included in the measurement of lease liabilities:" } } }, "localname": "CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "stringItemType" }, "kop_ChangeInDerivativeLiability": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10160.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Change in derivative liability", "label": "Change In Derivative Liability", "negatedLabel": "Change in derivative liability" } } }, "localname": "ChangeInDerivativeLiability", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "kop_CoalTarPitchCasesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Coal tar pitch cases.", "label": "Coal Tar Pitch Cases [Member]", "terseLabel": "Coal Tar Pitch Cases [Member]" } } }, "localname": "CoalTarPitchCasesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_CommittedLoanFacilityAgreementsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Committed loan facility agreements.", "label": "Committed Loan Facility Agreements [Member]", "terseLabel": "Committed Loan Facility Agreements [Member]" } } }, "localname": "CommittedLoanFacilityAgreementsMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "kop_CompensatoryDamagesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Compensatory damages.", "label": "Compensatory Damages [Member]", "terseLabel": "Compensatory Damages [Member]" } } }, "localname": "CompensatoryDamagesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_CostsChargedAgainstAssets": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Costs charged against assets", "label": "Costs Charged Against Assets", "negatedLabel": "Cost charged against assets" } } }, "localname": "CostsChargedAgainstAssets", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "monetaryItemType" }, "kop_CostsOfParticipatingInPotentiallyResponsiblePartiesGroup": { "auth_ref": [], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Costs of participating in potentially responsible parties group.", "label": "Costs Of Participating In Potentially Responsible Parties Group", "terseLabel": "Costs of participating in PRP group" } } }, "localname": "CostsOfParticipatingInPotentiallyResponsiblePartiesGroup", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "kop_CreosoteAndDistillatesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Creosote and distillates.", "label": "Creosote And Distillates [Member]", "terseLabel": "Creosote and Distillates [Member]" } } }, "localname": "CreosoteAndDistillatesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "kop_DebtMaturityDate": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Debt, maturity date.", "label": "Debt Maturity Date", "terseLabel": "Debt, Maturity" } } }, "localname": "DebtMaturityDate", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "gYearItemType" }, "kop_DepreciationAndAmortization1": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10150.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Depreciation and amortization1.", "label": "Depreciation And Amortization1", "verboseLabel": "Depreciation and amortization" } } }, "localname": "DepreciationAndAmortization1", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "kop_DerivativeNetCurrencyUnitsOutstanding": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Derivative net currency units outstanding.", "label": "Derivative Net Currency Units Outstanding", "terseLabel": "Net currency units outstanding" } } }, "localname": "DerivativeNetCurrencyUnitsOutstanding", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsSummaryOfNetCurrencyUnitsOutstandingDetail" ], "xbrltype": "monetaryItemType" }, "kop_DiscontinuedOperationsDisclosureTextBlock": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Discontinued operations.", "label": "Discontinued Operations Disclosure [Text Block]", "terseLabel": "Discontinued Operations" } } }, "localname": "DiscontinuedOperationsDisclosureTextBlock", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperations" ], "xbrltype": "textBlockItemType" }, "kop_DiscreteIncomeTaxExpenseBenefit": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Discrete income tax expense benefit.", "label": "Discrete Income Tax Expense Benefit", "negatedLabel": "Net tax benefit included in income taxes, discrete items", "terseLabel": "Net tax benefit included in income taxes, discrete items" } } }, "localname": "DiscreteIncomeTaxExpenseBenefit", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "kop_DisposalGroupIncludingDiscontinuedOperationDeferredTaxLiabilitiesCurrent1": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10090.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Disposal group including discontinued operation deferred tax liabilities current.", "label": "Disposal Group Including Discontinued Operation Deferred Tax Liabilities Current1", "terseLabel": "Deferred tax liabilities" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationDeferredTaxLiabilitiesCurrent1", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "kop_DisposalGroupIncludingDiscontinuedOperationIncomeTaxReceivable": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10180.0, "parentTag": "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Disposal group including discontinued operation income tax receivable.", "label": "Disposal Group Including Discontinued Operation Income Tax Receivable", "terseLabel": "Income tax receivable" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationIncomeTaxReceivable", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "kop_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilitiesCurrent": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10080.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Disposal group including discontinued operation operating lease liabilities current.", "label": "Disposal Group Including Discontinued Operation Operating Lease Liabilities Current", "terseLabel": "Current operating lease liabilities" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilitiesCurrent", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "kop_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilitiesNoncurrent": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10040.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Disposal group including discontinued operation operating lease liabilities noncurrent.", "label": "Disposal Group Including Discontinued Operation Operating Lease Liabilities Noncurrent", "terseLabel": "Operating lease liabilities" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilitiesNoncurrent", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "kop_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseRightOfUseAssetsCurrent": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10210.0, "parentTag": "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Disposal group including discontinued operation operating lease right of use assets current.", "label": "Disposal Group Including Discontinued Operation Operating Lease Right Of Use Assets Current", "terseLabel": "Operating lease right-of-use assets" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationOperatingLeaseRightOfUseAssetsCurrent", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "kop_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseRightOfUseAssetsNoncurrent": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10140.0, "parentTag": "us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Disposal group including discontinued operation operating lease right of use assets noncurrent.", "label": "Disposal Group Including Discontinued Operation Operating Lease Right Of Use Assets Noncurrent", "terseLabel": "Operating lease right-of-use assets" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationOperatingLeaseRightOfUseAssetsNoncurrent", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "kop_EffectOfExchangeRateOnCashAndCashEquivalentDiscontinuedOperations": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail": { "order": 10040.0, "parentTag": "us-gaap_NetCashProvidedByUsedInDiscontinuedOperations", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.", "label": "Effect Of Exchange Rate On Cash And Cash Equivalent Discontinued Operations", "terseLabel": "Effect of exchange rate changes on cash" } } }, "localname": "EffectOfExchangeRateOnCashAndCashEquivalentDiscontinuedOperations", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail" ], "xbrltype": "monetaryItemType" }, "kop_EffectiveIncomeTaxRateReconciliationGlobalIntangibleLowTaxedIncomeInclusionNetOfForeignTaxCredit": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail": { "order": 10040.0, "parentTag": "us-gaap_EffectiveIncomeTaxRateContinuingOperations", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Effective income tax rate reconciliation global intangible low-taxed income inclusion net of foreign tax credit.", "label": "Effective Income Tax Rate Reconciliation Global Intangible Low Taxed Income Inclusion Net Of Foreign Tax Credit", "terseLabel": "GILTI inclusion, net of foreign tax credits" } } }, "localname": "EffectiveIncomeTaxRateReconciliationGlobalIntangibleLowTaxedIncomeInclusionNetOfForeignTaxCredit", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail" ], "xbrltype": "percentItemType" }, "kop_EmployeeMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Employee.", "label": "Employee [Member]", "terseLabel": "Employee [Member]" } } }, "localname": "EmployeeMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_EnvironmentProtectionAuthorityMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Environment Protection Authority Member.", "label": "Environment Protection Authority [Member]", "terseLabel": "Environment Protection Authority [Member]" } } }, "localname": "EnvironmentProtectionAuthorityMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_EnvironmentalRemedialSiteMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Environmental remedial site.", "label": "Environmental Remedial Site [Member]", "terseLabel": "Environment Protection Authority [Member]" } } }, "localname": "EnvironmentalRemedialSiteMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_EnvironmentalRemedialSiteTwoMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Environmental remedial site two.", "label": "Environmental Remedial Site Two [Member]", "terseLabel": "Portland Harbor and Newark Bay CERCLA sites [Member]" } } }, "localname": "EnvironmentalRemedialSiteTwoMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_ExpectedPeriodForSalesAdjustment": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Expected period for sales adjustment", "label": "Expected Period For Sales Adjustment", "terseLabel": "Expected period for sales adjustment" } } }, "localname": "ExpectedPeriodForSalesAdjustment", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail" ], "xbrltype": "durationItemType" }, "kop_GrantsInMarchTwoThousandFifteenAndThereafterMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Grants in march two thousand fifteen and thereafter.", "label": "Grants In March Two Thousand Fifteen And Thereafter [Member]", "terseLabel": "Grants in March 2015 and Thereafter [Member]" } } }, "localname": "GrantsInMarchTwoThousandFifteenAndThereafterMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_HedgesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Derivatives listed as hedges.", "label": "Hedges [Member]", "terseLabel": "Hedges [Member]" } } }, "localname": "HedgesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfLossGainFromContractNotDesignatedAsHedgesDetail" ], "xbrltype": "domainItemType" }, "kop_IncomeTaxExpensePercentageOfPreTaxIncomeLoss": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Income tax expense percentage of pre tax income (loss).", "label": "Income Tax Expense Percentage Of Pre Tax Income Loss", "terseLabel": "Income taxes as a percentage of pretax income" } } }, "localname": "IncomeTaxExpensePercentageOfPreTaxIncomeLoss", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail" ], "xbrltype": "percentItemType" }, "kop_IncreaseDecreaseInCashAndCashEquivalentsOfDiscontinuedOperationsHeldForSale": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10050.0, "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Change in cash and cash equivalents of discontinued operations held for sale.", "label": "Increase Decrease In Cash And Cash Equivalents Of Discontinued Operations Held For Sale", "terseLabel": "Change in cash and cash equivalents of discontinued operations held for sale" } } }, "localname": "IncreaseDecreaseInCashAndCashEquivalentsOfDiscontinuedOperationsHeldForSale", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "kop_KSALimitedPartnershipMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "KSA limited partnership.", "label": "K S A Limited Partnership [Member]", "terseLabel": "KSA Limited Partnership [Member]" } } }, "localname": "KSALimitedPartnershipMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_KoppersJiangsuCarbonChemicalCompanyLimitedMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Koppers (Jiangsu) carbon chemical company limited.", "label": "Koppers Jiangsu Carbon Chemical Company Limited [Member]", "terseLabel": "Koppers (Jiangsu) Carbon Chemical Company Limited [Member]" } } }, "localname": "KoppersJiangsuCarbonChemicalCompanyLimitedMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesParentheticalDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentParentheticalDetail" ], "xbrltype": "domainItemType" }, "kop_LeasesSupplementalConsolidatedBalanceSheetInformationTableTextBlock": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Leases, supplemental consolidated balance sheet information.", "label": "Leases Supplemental Consolidated Balance Sheet Information Table [Text Block]", "terseLabel": "Schedule of Supplemental Consolidated Balance Sheet Information Related to Leases" } } }, "localname": "LeasesSupplementalConsolidatedBalanceSheetInformationTableTextBlock", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesTables" ], "xbrltype": "textBlockItemType" }, "kop_LossContingencyNumberOfStatesNewClaimsFiled": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Loss contingency number of states new claims filed.", "label": "Loss Contingency Number Of States New Claims Filed", "terseLabel": "Number of states with new claims filed" } } }, "localname": "LossContingencyNumberOfStatesNewClaimsFiled", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "integerItemType" }, "kop_MarchTwoThousandEighteenGrantMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "March two thousand eighteen grant.", "label": "March Two Thousand Eighteen Grant [Member]", "terseLabel": "March 2018 Grant [Member]" } } }, "localname": "MarchTwoThousandEighteenGrantMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "domainItemType" }, "kop_MarchTwoThousandNineteenGrantMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "March two thousand nineteen grant.", "label": "March Two Thousand Nineteen Grant [Member]", "terseLabel": "March 2019 Grant [Member]" } } }, "localname": "MarchTwoThousandNineteenGrantMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "domainItemType" }, "kop_MarchTwoThousandSeventeenGrantMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "March two thousand seventeen grant.", "label": "March Two Thousand Seventeen Grant [Member]", "terseLabel": "March 2017 Grant [Member]" } } }, "localname": "MarchTwoThousandSeventeenGrantMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "domainItemType" }, "kop_MarchTwoThousandTwentyGrantMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "March two thousand twenty grant member.", "label": "March Two Thousand Twenty Grant [Member]", "terseLabel": "March 2020 Grant [Member]" } } }, "localname": "MarchTwoThousandTwentyGrantMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "domainItemType" }, "kop_MayTwoThousandEighteenGrantMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "May two thousand eighteen grant.", "label": "May Two Thousand Eighteen Grant [Member]", "terseLabel": "May 2018 Grant [Member]" } } }, "localname": "MayTwoThousandEighteenGrantMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail" ], "xbrltype": "domainItemType" }, "kop_NapthaleneMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Napthalene.", "label": "Napthalene [Member]", "terseLabel": "Naphthalene [Member]" } } }, "localname": "NapthaleneMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "kop_NetCashProvidedByUsedInDivestitureOfBusinessesAndProductiveAssets": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10130.0, "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Net cash provided by used in divestiture of businesses and productive assets.", "label": "Net Cash Provided By Used In Divestiture Of Businesses And Productive Assets", "terseLabel": "Net cash provided by divestitures and asset sales" } } }, "localname": "NetCashProvidedByUsedInDivestitureOfBusinessesAndProductiveAssets", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "kop_NetPresentValueOfSelectedRemedyEstimation": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Net present value of selected remedy estimation.", "label": "Net Present Value Of Selected Remedy Estimation", "terseLabel": "Net present value of selected remedy estimation" } } }, "localname": "NetPresentValueOfSelectedRemedyEstimation", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "kop_NewSouthWalesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "New South Wales Member", "label": "New South Wales [Member]", "terseLabel": "New South Wales [Member]" } } }, "localname": "NewSouthWalesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_NumberOfAcquiredPlantSitesWithRecordedEnvironmentalRemediationLiability": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "The number of acquired plant sites where environmental remediation liabilities have been recorded for soil and groundwater contamination which occurred prior to acquisition.", "label": "Number Of Acquired Plant Sites With Recorded Environmental Remediation Liability", "terseLabel": "Number of plant sites" } } }, "localname": "NumberOfAcquiredPlantSitesWithRecordedEnvironmentalRemediationLiability", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "integerItemType" }, "kop_NumberOfNonQualifiedDefinedBenefitPensionPlans": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Number of non qualified defined benefit pension plans.", "label": "Number Of Non Qualified Defined Benefit Pension Plans", "terseLabel": "Number of domestic non-qualified defined benefit plans" } } }, "localname": "NumberOfNonQualifiedDefinedBenefitPensionPlans", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansAdditionalInformationDetail" ], "xbrltype": "integerItemType" }, "kop_NumberOfPotentiallyResponsibleParties": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Number of potentially responsible parties.", "label": "Number Of Potentially Responsible Parties", "terseLabel": "Number of potential responsible parties" } } }, "localname": "NumberOfPotentiallyResponsibleParties", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "integerItemType" }, "kop_NumberOfSitesListedOnNationalPrioritiesList": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Number of sites listed on national priorities list.", "label": "Number Of Sites Listed On National Priorities List", "terseLabel": "Sites listed on National Priorities List" } } }, "localname": "NumberOfSitesListedOnNationalPrioritiesList", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "integerItemType" }, "kop_OtherComprehensiveIncomeLossDueToChangeInAccountingStandard": { "auth_ref": [], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Other comprehensive income loss due to change in Accounting standard.", "label": "Other Comprehensive Income Loss Due To Change In Accounting Standard", "terseLabel": "Change in accounting standard" } } }, "localname": "OtherComprehensiveIncomeLossDueToChangeInAccountingStandard", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "monetaryItemType" }, "kop_OtherLoansMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Other loans.", "label": "Other Loans [Member]", "terseLabel": "Other Loans [Member]" } } }, "localname": "OtherLoansMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "kop_OtherProductsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Other products.", "label": "Other Products [Member]", "terseLabel": "Other Products [Member]" } } }, "localname": "OtherProductsMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "kop_PercentageOfAllowableBusinessInterestExpenseDeductionFromAdjustedTaxableIncome": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Percentage of allowable business interest expense deduction from adjusted taxable income.", "label": "Percentage Of Allowable Business Interest Expense Deduction From Adjusted Taxable Income", "terseLabel": "Percentage of allowable business interest expense deduction from adjusted taxable income" } } }, "localname": "PercentageOfAllowableBusinessInterestExpenseDeductionFromAdjustedTaxableIncome", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail" ], "xbrltype": "percentItemType" }, "kop_PercentageOfOwnershipInterest": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Percentage of ownership interest.", "label": "Percentage Of Ownership Interest", "terseLabel": "Percentage of operations in Tangshan, China owned by the company" } } }, "localname": "PercentageOfOwnershipInterest", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "percentItemType" }, "kop_PerformanceChemicalsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Performance chemicals.", "label": "Performance Chemicals [Member]", "terseLabel": "Performance Chemicals [Member]" } } }, "localname": "PerformanceChemicalsMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail" ], "xbrltype": "domainItemType" }, "kop_PhthalicAnhydrideAndOtherChemicalsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Phthalic anhydride and other chemicals.", "label": "Phthalic Anhydride And Other Chemicals [Member]", "terseLabel": "Phthalic Anhydride and Other Chemicals [Member]" } } }, "localname": "PhthalicAnhydrideAndOtherChemicalsMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "kop_PitchAndRelatedProductsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Pitch and related products.", "label": "Pitch And Related Products [Member]", "terseLabel": "Pitch and Related Products [Member]" } } }, "localname": "PitchAndRelatedProductsMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "kop_PunitiveDamagesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Punitive damages.", "label": "Punitive Damages [Member]", "terseLabel": "Punitive Damages [Member]" } } }, "localname": "PunitiveDamagesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_RailJointsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Rail joints.", "label": "Rail Joints [Member]", "terseLabel": "Rail Joints [Member]" } } }, "localname": "RailJointsMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "kop_RailroadAndUtilityProductsAndServicesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Railroad and utility products and services.", "label": "Railroad And Utility Products And Services [Member]", "terseLabel": "Railroad and Utility Products and Services [Member]" } } }, "localname": "RailroadAndUtilityProductsAndServicesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail" ], "xbrltype": "domainItemType" }, "kop_RailroadInfrastructureServicesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Railroad infrastructure services.", "label": "Railroad Infrastructure Services [Member]", "terseLabel": "Railroad Infrastructure Services [Member]" } } }, "localname": "RailroadInfrastructureServicesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "kop_RailroadTreatedProductsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Railroad treated products.", "label": "Railroad Treated Products [Member]", "terseLabel": "Railroad Treated Products [Member]" } } }, "localname": "RailroadTreatedProductsMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "kop_RestructuringReserveAccrual": { "auth_ref": [], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Restructuring reserve accrual.", "label": "Restructuring Reserve Accrual", "terseLabel": "Accrual" } } }, "localname": "RestructuringReserveAccrual", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "monetaryItemType" }, "kop_SalariedAndHourlyEmployeesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Salaried and hourly employees.", "label": "Salaried And Hourly Employees [Member]", "terseLabel": "Salaried and Hourly Employees [Member]" } } }, "localname": "SalariedAndHourlyEmployeesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_SeniorSecuredCreditFacilitiesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Senior secured credit facilities.", "label": "Senior Secured Credit Facilities [Member]", "terseLabel": "Senior Secured Credit Facilities [Member]" } } }, "localname": "SeniorSecuredCreditFacilitiesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "kop_SeniorSecuredRevolvingCreditFacilityMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Senior Secured Revolving Credit Facility", "label": "Senior Secured Revolving Credit Facility [Member]", "terseLabel": "Senior Secured Revolving Credit Facility [Member]" } } }, "localname": "SeniorSecuredRevolvingCreditFacilityMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsToBeVestedIfPerformanceCriteriaNotAchieved": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Share based compensation arrangement by share based payment award equity instruments other than options to be vested if performance criteria not achieved.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options To Be Vested If Performance Criteria Not Achieved", "terseLabel": "Vesting performance stock units if minimum performance criteria are not achieved" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsToBeVestedIfPerformanceCriteriaNotAchieved", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "sharesItemType" }, "kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsLookBackPeriod": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Share based compensation arrangement by share based payment award fair value assumptions look back period.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Look Back Period", "terseLabel": "Look-back period in years" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsLookBackPeriod", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail" ], "xbrltype": "durationItemType" }, "kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfTargetAwardParticipantsEarn": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Share based compensation arrangement by share based payment award percentage of target award the participants earn.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Percentage Of Target Award Participants Earn", "terseLabel": "Percentage of target award earned by participants" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfTargetAwardParticipantsEarn", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "percentItemType" }, "kop_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosuresAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Share-based compensation arrangement by share-based payment award, options outstanding, weighted average exercise price, and additional disclosures.", "label": "Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Exercise Price And Additional Disclosures [Abstract]" } } }, "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosuresAbstract", "nsuri": "http://www.koppers.com/20200331", "xbrltype": "stringItemType" }, "kop_SixPercentSeniorNotesDueTwoThousandTwentyFiveMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Six percent senior notes due two thousand twenty five.", "label": "Six Percent Senior Notes Due Two Thousand Twenty Five [Member]", "terseLabel": "6.00 percent Senior Notes due 2025 [Member]" } } }, "localname": "SixPercentSeniorNotesDueTwoThousandTwentyFiveMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "kop_TangshanKoppersKailuanCarbonChemicalCompanyLimitedMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Tangshan Koppers Kailuan Carbon Chemical Company Limited.", "label": "Tangshan Koppers Kailuan Carbon Chemical Company Limited [Member]", "terseLabel": "Tangshan Koppers Kailuan Carbon Chemical Company Limited [Member]" } } }, "localname": "TangshanKoppersKailuanCarbonChemicalCompanyLimitedMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_TermLoanMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Term loan.", "label": "Term Loan [Member]", "terseLabel": "Term Loan [Member]" } } }, "localname": "TermLoanMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "kop_TwoThousandEighteenThroughTwoThousandTwentyMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Two thousand eighteen through two thousand twenty.", "label": "Two Thousand Eighteen Through Two Thousand Twenty [Member]", "terseLabel": "2018 - 2020 [Member]" } } }, "localname": "TwoThousandEighteenThroughTwoThousandTwentyMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "domainItemType" }, "kop_TwoThousandNineteenThroughTwoThousandTwentyOneMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Two thousand nineteen through two thousand twenty one.", "label": "Two Thousand Nineteen Through Two Thousand Twenty One [Member]", "terseLabel": "2019 - 2021 [Member]" } } }, "localname": "TwoThousandNineteenThroughTwoThousandTwentyOneMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "domainItemType" }, "kop_TwoThousandSeventeenThroughTwoThousandNineteenMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Two thousand seventeen through two thousand nineteen.", "label": "Two Thousand Seventeen Through Two Thousand Nineteen [Member]", "terseLabel": "2017 - 2019 [Member]" } } }, "localname": "TwoThousandSeventeenThroughTwoThousandNineteenMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_TwoThousandTwentyThroughTwoThousandTwentyTwoMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Two thousand twenty through two thousand twenty two member.", "label": "Two Thousand Twenty Through Two Thousand Twenty Two [Member]", "terseLabel": "2020 - 2022 [Member]" } } }, "localname": "TwoThousandTwentyThroughTwoThousandTwentyTwoMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "domainItemType" }, "kop_UndiscountedCostOfSelectedRemedyEstimation": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Undiscounted cost of selected remedy estimation.", "label": "Undiscounted Cost Of Selected Remedy Estimation", "terseLabel": "Undiscounted cost of selected remedy estimation" } } }, "localname": "UndiscountedCostOfSelectedRemedyEstimation", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "kop_UtilityAndIndustrialProductsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Utility and industrial products.", "label": "Utility And Industrial Products [Member]", "terseLabel": "Utility and Industrial Products [Member]" } } }, "localname": "UtilityAndIndustrialProductsMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "kop_UtilityPolesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Utility poles.", "label": "Utility Poles [Member]", "terseLabel": "Utility Poles [Member]" } } }, "localname": "UtilityPolesMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "kop_WoodPreservativeProductMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Wood preservative product.", "label": "Wood Preservative Product [Member]", "terseLabel": "Wood Preservative Products [Member]" } } }, "localname": "WoodPreservativeProductMember", "nsuri": "http://www.koppers.com/20200331", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "srt_ConsolidationItemsAxis": { "auth_ref": [ "r144", "r153" ], "lang": { "en-US": { "role": { "documentation": "Information by components, eliminations, non-segment corporate-level activity and reconciling items used in consolidating a parent entity and its subsidiaries or its operating segments.", "label": "Consolidation Items [Axis]", "terseLabel": "Consolidation Items" } } }, "localname": "ConsolidationItemsAxis", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail" ], "xbrltype": "stringItemType" }, "srt_ConsolidationItemsDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Components, elimination, non-segment corporate-level activity and reconciling items used in consolidating a parent entity and its subsidiaries or its operating segments.", "label": "Consolidation Items [Domain]", "terseLabel": "Consolidation Items" } } }, "localname": "ConsolidationItemsDomain", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail" ], "xbrltype": "domainItemType" }, "srt_CounterpartyNameAxis": { "auth_ref": [ "r71", "r119", "r457" ], "lang": { "en-US": { "role": { "documentation": "Information by name of counterparty. A counterparty is the other party that participates in a financial transaction. Examples include, but not limited to, the name of the financial institution.", "label": "Counterparty Name [Axis]", "terseLabel": "Counterparty Name" } } }, "localname": "CounterpartyNameAxis", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "srt_DirectorMember": { "auth_ref": [ "r159" ], "lang": { "en-US": { "role": { "documentation": "Person serving on board of directors.", "label": "Director [Member]", "terseLabel": "Board of Directors [Member]" } } }, "localname": "DirectorMember", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "srt_EquityMethodInvesteeNameDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Name of investment, including named security. Excludes consolidated entity.", "label": "Equity Method Investee Name [Domain]", "terseLabel": "Investment, Name" } } }, "localname": "EquityMethodInvesteeNameDomain", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesParentheticalDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentParentheticalDetail" ], "xbrltype": "domainItemType" }, "srt_ExecutiveOfficerMember": { "auth_ref": [ "r159" ], "lang": { "en-US": { "role": { "documentation": "Person with designation of executive officer.", "label": "Executive Officer [Member]", "terseLabel": "Executive Officer [Member]" } } }, "localname": "ExecutiveOfficerMember", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "srt_LitigationCaseAxis": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Information by type of judicial proceeding, alternative dispute resolution or claim.", "label": "Litigation Case [Axis]", "terseLabel": "Litigation Case" } } }, "localname": "LitigationCaseAxis", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "srt_LitigationCaseTypeDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Judicial proceeding, alternative dispute resolution or claim. For example, but not limited to, name of case, category of litigation, or other differentiating information.", "label": "Litigation Case Type [Domain]", "terseLabel": "Litigation Case" } } }, "localname": "LitigationCaseTypeDomain", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "srt_MaximumMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Upper limit of the provided range.", "label": "Maximum [Member]", "terseLabel": "Maximum [Member]" } } }, "localname": "MaximumMember", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "domainItemType" }, "srt_MinimumMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Lower limit of the provided range.", "label": "Minimum [Member]", "terseLabel": "Minimum [Member]" } } }, "localname": "MinimumMember", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "domainItemType" }, "srt_ProductOrServiceAxis": { "auth_ref": [ "r156", "r252", "r254", "r442", "r443" ], "lang": { "en-US": { "role": { "documentation": "Information by product and service, or group of similar products and similar services.", "label": "Product Or Service [Axis]", "terseLabel": "Product and Service" } } }, "localname": "ProductOrServiceAxis", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "stringItemType" }, "srt_ProductsAndServicesDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Product or service, or a group of similar products or similar services.", "label": "Products And Services [Domain]", "terseLabel": "Product and Service" } } }, "localname": "ProductsAndServicesDomain", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "domainItemType" }, "srt_RangeAxis": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Information by statistical measurement. Includes, but is not limited to, minimum, maximum, weighted average, arithmetic average, and median.", "label": "Range [Axis]", "terseLabel": "Statistical Measurement" } } }, "localname": "RangeAxis", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "stringItemType" }, "srt_RangeMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Statistical measurement. Includes, but is not limited to, minimum, maximum, weighted average, arithmetic average, and median.", "label": "Range [Member]", "terseLabel": "Statistical Measurement" } } }, "localname": "RangeMember", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "domainItemType" }, "srt_RepurchaseAgreementCounterpartyNameDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Named other party that participates in a financial transaction. Examples include, but not limited to, the name of the financial institution.", "label": "Repurchase Agreement Counterparty Name [Domain]", "terseLabel": "Counterparty Name" } } }, "localname": "RepurchaseAgreementCounterpartyNameDomain", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "srt_ScenarioForecastMember": { "auth_ref": [ "r453" ], "lang": { "en-US": { "role": { "documentation": "Information reported for future period.", "label": "Scenario Forecast [Member]", "terseLabel": "Scenario, Forecast [Member]" } } }, "localname": "ScenarioForecastMember", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "srt_ScenarioUnspecifiedDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Scenario reported, distinguishing information from actual fact. Includes, but is not limited to, pro forma and forecast. Excludes actual facts.", "label": "Scenario Unspecified [Domain]", "terseLabel": "Scenario" } } }, "localname": "ScenarioUnspecifiedDomain", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "srt_ScheduleOfCondensedBalanceSheetTableTextBlock": { "auth_ref": [ "r456" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of condensed balance sheet, including, but not limited to, balance sheets of consolidated entities and consolidation eliminations.", "label": "Schedule Of Condensed Balance Sheet Table [Text Block]", "terseLabel": "Schedule of Carrying Amount of Assets and Liabilities by Major Class Classified as Held for Sale" } } }, "localname": "ScheduleOfCondensedBalanceSheetTableTextBlock", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsTables" ], "xbrltype": "textBlockItemType" }, "srt_ScheduleOfCondensedCashFlowStatementTableTextBlock": { "auth_ref": [ "r456" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of condensed cash flow statement, including, but not limited to, cash flow statements of consolidated entities and consolidation eliminations.", "label": "Schedule Of Condensed Cash Flow Statement Table [Text Block]", "terseLabel": "Schedule of Net cash Inflows and Outflows From Discontinued Operations" } } }, "localname": "ScheduleOfCondensedCashFlowStatementTableTextBlock", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsTables" ], "xbrltype": "textBlockItemType" }, "srt_ScheduleOfCondensedIncomeStatementTableTextBlock": { "auth_ref": [ "r456" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of condensed income statement, including, but not limited to, income statements of consolidated entities and consolidation eliminations.", "label": "Schedule Of Condensed Income Statement Table [Text Block]", "terseLabel": "Schedule of Net Sales and Operating (Loss) Profit from Discontinued Operations" } } }, "localname": "ScheduleOfCondensedIncomeStatementTableTextBlock", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsTables" ], "xbrltype": "textBlockItemType" }, "srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis": { "auth_ref": [ "r164" ], "lang": { "en-US": { "role": { "documentation": "Information by name of investment, including named security. Excludes consolidated entity.", "label": "Schedule Of Equity Method Investment Equity Method Investee Name [Axis]", "terseLabel": "Investment, Name" } } }, "localname": "ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesParentheticalDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentParentheticalDetail" ], "xbrltype": "stringItemType" }, "srt_SegmentGeographicalDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Geographical area.", "label": "Segment Geographical [Domain]", "terseLabel": "Geographical" } } }, "localname": "SegmentGeographicalDomain", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "srt_StatementGeographicalAxis": { "auth_ref": [ "r157", "r252", "r255", "r444", "r445", "r446", "r454", "r455" ], "lang": { "en-US": { "role": { "documentation": "Information by geographical components.", "label": "Statement Geographical [Axis]", "terseLabel": "Geographical" } } }, "localname": "StatementGeographicalAxis", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "srt_StatementScenarioAxis": { "auth_ref": [ "r221", "r409" ], "lang": { "en-US": { "role": { "documentation": "Information by scenario reported, distinguishing information from actual fact. Includes, but is not limited to, pro forma and forecast. Excludes actual facts.", "label": "Statement Scenario [Axis]", "terseLabel": "Scenario" } } }, "localname": "StatementScenarioAxis", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "srt_TitleOfIndividualAxis": { "auth_ref": [ "r159", "r408" ], "lang": { "en-US": { "role": { "documentation": "Information by title of individual or nature of relationship to individual or group of individuals.", "label": "Title Of Individual [Axis]", "terseLabel": "Title of Individual" } } }, "localname": "TitleOfIndividualAxis", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "srt_TitleOfIndividualWithRelationshipToEntityDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Title of individual, or nature of relationship to individual or group of individuals.", "label": "Title Of Individual With Relationship To Entity [Domain]", "terseLabel": "Title of Individual" } } }, "localname": "TitleOfIndividualWithRelationshipToEntityDomain", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "srt_WeightedAverageMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Average of a range of values, calculated with consideration of proportional relevance.", "label": "Weighted Average [Member]", "terseLabel": "Target Shares [Member]" } } }, "localname": "WeightedAverageMember", "nsuri": "http://fasb.org/srt/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "domainItemType" }, "stpr_OR": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "OREGON", "terseLabel": "Oregon [Member]" } } }, "localname": "OR", "nsuri": "http://xbrl.sec.gov/stpr/2018-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "stpr_PA": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "PENNSYLVANIA", "terseLabel": "Pennsylvania [Member]" } } }, "localname": "PA", "nsuri": "http://xbrl.sec.gov/stpr/2018-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "stpr_TN": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "TENNESSEE", "terseLabel": "Tennessee [Member]" } } }, "localname": "TN", "nsuri": "http://xbrl.sec.gov/stpr/2018-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "us-gaap_AccountingChangesAndErrorCorrectionsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Accounting Changes And Error Corrections [Abstract]" } } }, "localname": "AccountingChangesAndErrorCorrectionsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_AccountsPayableCurrent": { "auth_ref": [ "r48" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10190.0, "parentTag": "us-gaap_LiabilitiesCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).", "label": "Accounts Payable Current", "terseLabel": "Accounts payable" } } }, "localname": "AccountsPayableCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccountsReceivableNetCurrent": { "auth_ref": [ "r21", "r34", "r160", "r161", "r253" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10330.0, "parentTag": "us-gaap_AssetsCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.", "label": "Accounts Receivable Net Current", "terseLabel": "Accounts receivable, net of allowance of $2.4 and $2.6" } } }, "localname": "AccountsReceivableNetCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccrualForEnvironmentalLossContingencies": { "auth_ref": [ "r207", "r219", "r220" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Total costs accrued as of the balance sheet date for environmental loss contingencies.", "label": "Accrual For Environmental Loss Contingencies", "periodEndLabel": "Balance at end of period", "periodStartLabel": "Balance at beginning of year", "terseLabel": "Environmental remediation and regulation liability" } } }, "localname": "AccrualForEnvironmentalLossContingencies", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesChangesInAccruedLiabilityForEnvironmentalMattersDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses": { "auth_ref": [ "r230" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of expense for newly incurred environmental loss contingencies. Includes, but is not limited to, remediation expense and interest accretion.", "label": "Accrual For Environmental Loss Contingencies Charges To Expense For New Losses", "verboseLabel": "Expense" } } }, "localname": "AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesChangesInAccruedLiabilityForEnvironmentalMattersDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccrualForEnvironmentalLossContingenciesForeignCurrencyTranslationGainLoss": { "auth_ref": [ "r230" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of foreign currency translation gain (loss) which decreases (increases) the accrual for environmental loss contingencies.", "label": "Accrual For Environmental Loss Contingencies Foreign Currency Translation Gain Loss", "terseLabel": "Currency translation" } } }, "localname": "AccrualForEnvironmentalLossContingenciesForeignCurrencyTranslationGainLoss", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesChangesInAccruedLiabilityForEnvironmentalMattersDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForRevisionInEstimates": { "auth_ref": [ "r230" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of expense (reversal of expense) which increases (decreases) the accrual for environmental loss contingencies from revisions in estimates to existing obligations. Excludes changes related to business acquisitions, divestitures, or currency movement.", "label": "Accrual For Environmental Loss Contingencies Increase Decrease For Revision In Estimates", "terseLabel": "Reversal of reserves" } } }, "localname": "AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForRevisionInEstimates", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesChangesInAccruedLiabilityForEnvironmentalMattersDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccrualForEnvironmentalLossContingenciesPayments1": { "auth_ref": [ "r110", "r229" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of cash outflow to settle environmental loss contingencies.", "label": "Accrual For Environmental Loss Contingencies Payments1", "negatedLabel": "Cash expenditures" } } }, "localname": "AccrualForEnvironmentalLossContingenciesPayments1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesChangesInAccruedLiabilityForEnvironmentalMattersDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccruedEnvironmentalLossContingenciesCurrent": { "auth_ref": [ "r24", "r52", "r201", "r207", "r220" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable in twelve months or in the next operating cycle if longer.", "label": "Accrued Environmental Loss Contingencies Current", "terseLabel": "Accrued liability for environmental matters, current" } } }, "localname": "AccruedEnvironmentalLossContingenciesCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccruedLiabilitiesCurrent": { "auth_ref": [ "r52" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10200.0, "parentTag": "us-gaap_LiabilitiesCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).", "label": "Accrued Liabilities Current", "terseLabel": "Accrued liabilities" } } }, "localname": "AccruedLiabilitiesCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment": { "auth_ref": [ "r46", "r188" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail": { "order": 10020.0, "parentTag": "us-gaap_PropertyPlantAndEquipmentNet", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.", "label": "Accumulated Depreciation Depletion And Amortization Property Plant And Equipment", "terseLabel": "Less accumulated depreciation" } } }, "localname": "AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Accumulated Other Comprehensive Income Loss [Line Items]", "terseLabel": "Accumulated Other Comprehensive Income (Loss) [Line Items]" } } }, "localname": "AccumulatedOtherComprehensiveIncomeLossLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "stringItemType" }, "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax": { "auth_ref": [ "r77", "r79", "r80" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10100.0, "parentTag": "us-gaap_StockholdersEquity", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.", "label": "Accumulated Other Comprehensive Income Loss Net Of Tax", "terseLabel": "Accumulated other comprehensive loss" } } }, "localname": "AccumulatedOtherComprehensiveIncomeLossNetOfTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_AccumulatedOtherComprehensiveIncomeLossTable": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Disclosure of information about components of accumulated other comprehensive income (loss).", "label": "Accumulated Other Comprehensive Income Loss [Table]", "terseLabel": "Accumulated Other Comprehensive Income Loss [Table]" } } }, "localname": "AccumulatedOtherComprehensiveIncomeLossTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "stringItemType" }, "us-gaap_AccumulatedOtherComprehensiveIncomeMember": { "auth_ref": [ "r76", "r80", "r83", "r343" ], "lang": { "en-US": { "role": { "documentation": "Accumulated increase (decrease) in equity from transactions and other events and circumstances from non-owner sources, attributable to the parent. Excludes net income (loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners.", "label": "Accumulated Other Comprehensive Income [Member]", "terseLabel": "Accumulated Other Comprehensive (Loss) [Member]" } } }, "localname": "AccumulatedOtherComprehensiveIncomeMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "domainItemType" }, "us-gaap_AdditionalPaidInCapitalCommonStock": { "auth_ref": [ "r35" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10080.0, "parentTag": "us-gaap_StockholdersEquity", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Value received from shareholders in common stock-related transactions that are in excess of par value or stated value and amounts received from other stock-related transactions. Includes only common stock transactions (excludes preferred stock transactions). May be called contributed capital, capital in excess of par, capital surplus, or paid-in capital.", "label": "Additional Paid In Capital Common Stock", "terseLabel": "Additional paid-in capital" } } }, "localname": "AdditionalPaidInCapitalCommonStock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_AdditionalPaidInCapitalMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders.", "label": "Additional Paid In Capital [Member]", "terseLabel": "Additional Paid-in Capital [Member]" } } }, "localname": "AdditionalPaidInCapitalMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "domainItemType" }, "us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract]", "terseLabel": "Adjustments to reconcile net cash (used in) provided by operating activities:" } } }, "localname": "AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_AllOtherSegmentsMember": { "auth_ref": [ "r137", "r138", "r139", "r140", "r141", "r142" ], "lang": { "en-US": { "role": { "documentation": "Operating segments classified as other. Excludes intersegment elimination and reconciling items.", "label": "All Other Segments [Member]", "terseLabel": "All Other [Member]" } } }, "localname": "AllOtherSegmentsMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_AllocatedShareBasedCompensationExpense": { "auth_ref": [ "r280", "r308", "r312" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.", "label": "Allocated Share Based Compensation Expense", "terseLabel": "Stock-based compensation expense" } } }, "localname": "AllocatedShareBasedCompensationExpense", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount, after tax, of expense for award under share-based payment arrangement.", "label": "Allocated Share Based Compensation Expense Net Of Tax", "terseLabel": "Decrease in net income attributable to Koppers" } } }, "localname": "AllocatedShareBasedCompensationExpenseNetOfTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent": { "auth_ref": [ "r40", "r162", "r166" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of allowance for credit loss on accounts receivable, classified as current.", "label": "Allowance For Doubtful Accounts Receivable Current", "terseLabel": "Accounts receivable, allowance" } } }, "localname": "AllowanceForDoubtfulAccountsReceivableCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetParenthetical" ], "xbrltype": "monetaryItemType" }, "us-gaap_AmortizationOfDebtDiscountPremium": { "auth_ref": [ "r100", "r115", "r391" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10180.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.", "label": "Amortization Of Debt Discount Premium", "terseLabel": "Non-cash interest expense" } } }, "localname": "AmortizationOfDebtDiscountPremium", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_AmortizationOfFinancingCosts": { "auth_ref": [ "r95", "r115", "r393" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of amortization expense attributable to debt issuance costs.", "label": "Amortization Of Financing Costs", "terseLabel": "Quarterly amortization" } } }, "localname": "AmortizationOfFinancingCosts", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount": { "auth_ref": [ "r133" ], "lang": { "en-US": { "role": { "documentation": "Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.", "label": "Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount", "terseLabel": "Antidilutive securities excluded from computation of diluted earnings per common share" } } }, "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_AssetImpairmentCharges": { "auth_ref": [ "r115", "r184" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.", "label": "Asset Impairment Charges", "terseLabel": "Impairment charge" } } }, "localname": "AssetImpairmentCharges", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AssetRetirementObligation": { "auth_ref": [ "r196" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.", "label": "Asset Retirement Obligation", "periodEndLabel": "Balance at end of period", "periodStartLabel": "Asset retirement obligation at beginning of year" } } }, "localname": "AssetRetirementObligation", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligationsScheduleOfChangesInCarryingValuesOfAssetRetirementObligationsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AssetRetirementObligationAccretionExpense": { "auth_ref": [ "r195", "r197" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.", "label": "Asset Retirement Obligation Accretion Expense", "terseLabel": "Accretion expense" } } }, "localname": "AssetRetirementObligationAccretionExpense", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligationsScheduleOfChangesInCarryingValuesOfAssetRetirementObligationsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AssetRetirementObligationCashPaidToSettle": { "auth_ref": [ "r109" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of cash paid during the period to settle an asset retirement obligation. Amounts paid to settle an asset retirement obligation are generally included in the operating section of the Statement of Cash Flows.", "label": "Asset Retirement Obligation Cash Paid To Settle", "negatedLabel": "Cash expenditures" } } }, "localname": "AssetRetirementObligationCashPaidToSettle", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligationsScheduleOfChangesInCarryingValuesOfAssetRetirementObligationsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AssetRetirementObligationDisclosureAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Asset Retirement Obligation Disclosure [Abstract]" } } }, "localname": "AssetRetirementObligationDisclosureAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_AssetRetirementObligationDisclosureTextBlock": { "auth_ref": [ "r199" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for an asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.", "label": "Asset Retirement Obligation Disclosure [Text Block]", "terseLabel": "Asset Retirement Obligations" } } }, "localname": "AssetRetirementObligationDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligations" ], "xbrltype": "textBlockItemType" }, "us-gaap_AssetRetirementObligationForeignCurrencyTranslationGainLoss": { "auth_ref": [ "r196" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of foreign currency translation gain (loss) which decreases (increases) asset retirement obligations.", "label": "Asset Retirement Obligation Foreign Currency Translation Gain Loss", "terseLabel": "Currency translation" } } }, "localname": "AssetRetirementObligationForeignCurrencyTranslationGainLoss", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligationsScheduleOfChangesInCarryingValuesOfAssetRetirementObligationsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AssetRetirementObligationRevisionOfEstimate": { "auth_ref": [ "r194", "r198" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.", "label": "Asset Retirement Obligation Revision Of Estimate", "terseLabel": "Revision in estimated cash flows" } } }, "localname": "AssetRetirementObligationRevisionOfEstimate", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligationsScheduleOfChangesInCarryingValuesOfAssetRetirementObligationsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_Assets": { "auth_ref": [ "r147", "r412", "r429" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.", "label": "Assets", "terseLabel": "Assets", "totalLabel": "Total assets" } } }, "localname": "Assets", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_AssetsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Assets [Abstract]", "terseLabel": "Assets" } } }, "localname": "AssetsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "stringItemType" }, "us-gaap_AssetsCurrent": { "auth_ref": [ "r22", "r23", "r70" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10240.0, "parentTag": "us-gaap_Assets", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.", "label": "Assets Current", "totalLabel": "Total current assets" } } }, "localname": "AssetsCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation": { "auth_ref": [ "r0", "r1", "r14", "r15", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as assets attributable to disposal group held for sale or disposed of.", "label": "Assets Of Disposal Group Including Discontinued Operation", "terseLabel": "Assets of discontinued operations held for sale", "totalLabel": "Total assets held for sale", "verboseLabel": "Fair value" } } }, "localname": "AssetsOfDisposalGroupIncludingDiscontinuedOperation", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentParentheticalDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Assets Of Disposal Group Including Discontinued Operation [Abstract]", "terseLabel": "Assets" } } }, "localname": "AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "stringItemType" }, "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent": { "auth_ref": [ "r0", "r1", "r14", "r15", "r185", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10110.0, "parentTag": "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10360.0, "parentTag": "us-gaap_AssetsCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as assets attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer.", "label": "Assets Of Disposal Group Including Discontinued Operation Current", "terseLabel": "Assets of discontinued operations held for sale", "totalLabel": "Total current assets held for sale" } } }, "localname": "AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_AwardDateAxis": { "auth_ref": [ "r282", "r310" ], "lang": { "en-US": { "role": { "documentation": "Information by date or year award under share-based payment arrangement is granted.", "label": "Award Date [Axis]", "terseLabel": "Award Date" } } }, "localname": "AwardDateAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_AwardDateDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Date or year award under share-based payment arrangement is granted.", "label": "Award Date [Domain]", "terseLabel": "Award Date" } } }, "localname": "AwardDateDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_AwardTypeAxis": { "auth_ref": [ "r282", "r310" ], "lang": { "en-US": { "role": { "documentation": "Information by type of award under share-based payment arrangement.", "label": "Award Type [Axis]", "terseLabel": "Award Type" } } }, "localname": "AwardTypeAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "stringItemType" }, "us-gaap_BalanceSheetLocationAxis": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Information by location on balance sheet (statement of financial position).", "label": "Balance Sheet Location [Axis]", "terseLabel": "Balance Sheet Location" } } }, "localname": "BalanceSheetLocationAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_BalanceSheetLocationDomain": { "auth_ref": [ "r360", "r363" ], "lang": { "en-US": { "role": { "documentation": "Location in the balance sheet (statement of financial position).", "label": "Balance Sheet Location [Domain]", "terseLabel": "Balance Sheet Location" } } }, "localname": "BalanceSheetLocationDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_BuildingMember": { "auth_ref": [ "r187" ], "lang": { "en-US": { "role": { "documentation": "Facility held for productive use including, but not limited to, office, production, storage and distribution facilities.", "label": "Building [Member]", "terseLabel": "Buildings [Member]" } } }, "localname": "BuildingMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail" ], "xbrltype": "domainItemType" }, "us-gaap_BusinessAcquisitionAcquireeDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Identification of the acquiree in a material business combination (or series of individually immaterial business combinations), which may include the name or other type of identification of the acquiree.", "label": "Business Acquisition Acquiree [Domain]", "terseLabel": "Business Acquisition, Acquiree" } } }, "localname": "BusinessAcquisitionAcquireeDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "us-gaap_BusinessAcquisitionAxis": { "auth_ref": [ "r332", "r333" ], "lang": { "en-US": { "role": { "documentation": "Information by business combination or series of individually immaterial business combinations.", "label": "Business Acquisition [Axis]", "terseLabel": "Business Acquisition" } } }, "localname": "BusinessAcquisitionAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_CarryingReportedAmountFairValueDisclosureMember": { "auth_ref": [ "r385", "r386" ], "lang": { "en-US": { "role": { "documentation": "Measured as reported on the statement of financial position (balance sheet).", "label": "Carrying Reported Amount Fair Value Disclosure [Member]", "terseLabel": "Carrying Value [Member]" } } }, "localname": "CarryingReportedAmountFairValueDisclosureMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_CashAndCashEquivalentsAtCarryingValue": { "auth_ref": [ "r19", "r44", "r117" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10320.0, "parentTag": "us-gaap_AssetsCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.", "label": "Cash And Cash Equivalents At Carrying Value", "periodEndLabel": "Cash and cash equivalents at end of period", "periodStartLabel": "Cash and cash equivalents at beginning of period", "terseLabel": "Cash and cash equivalents" } } }, "localname": "CashAndCashEquivalentsAtCarryingValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_CashAndCashEquivalentsFairValueDisclosure": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.", "label": "Cash And Cash Equivalents Fair Value Disclosure", "terseLabel": "Cash and cash equivalents, including restricted cash" } } }, "localname": "CashAndCashEquivalentsFairValueDisclosure", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect": { "auth_ref": [ "r112", "r387" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of increase (decrease) in cash, cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; including effect from exchange rate change. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.", "label": "Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect", "totalLabel": "Net increase (decrease) in cash and cash equivalents" } } }, "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_CashFlowHedgingMember": { "auth_ref": [ "r356" ], "lang": { "en-US": { "role": { "documentation": "Hedge of the exposure to variability in the cash flows of a recognized asset or liability, or of a forecasted transaction, that is attributable to a particular risk.", "label": "Cash Flow Hedging [Member]", "terseLabel": "Cash Flow Hedging [Member]" } } }, "localname": "CashFlowHedgingMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Cash Flow Noncash Investing And Financing Activities Disclosure [Abstract]", "terseLabel": "Supplemental disclosure of non-cash investing and financing activities:" } } }, "localname": "CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations": { "auth_ref": [ "r112" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail": { "order": 10030.0, "parentTag": "us-gaap_NetCashProvidedByUsedInDiscontinuedOperations", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of cash inflow (outflow) of financing activities of discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.", "label": "Cash Provided By Used In Financing Activities Discontinued Operations", "terseLabel": "Net cash used in financing activities" } } }, "localname": "CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations": { "auth_ref": [ "r13", "r112" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail": { "order": 10020.0, "parentTag": "us-gaap_NetCashProvidedByUsedInDiscontinuedOperations", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of cash inflow (outflow) of investing activities of discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.", "label": "Cash Provided By Used In Investing Activities Discontinued Operations", "terseLabel": "Net cash used in investing activities" } } }, "localname": "CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations": { "auth_ref": [ "r13", "r112" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail": { "order": 10010.0, "parentTag": "us-gaap_NetCashProvidedByUsedInDiscontinuedOperations", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of cash inflow (outflow) of operating activities of discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.", "label": "Cash Provided By Used In Operating Activities Discontinued Operations", "terseLabel": "Net cash (used in) provided by operating activities" } } }, "localname": "CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_CommitmentsAndContingencies": { "auth_ref": [ "r59", "r220", "r418", "r435" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10020.0, "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Represents the caption on the face of the balance sheet to indicate that the entity has entered into (1) purchase or supply arrangements that will require expending a portion of its resources to meet the terms thereof, and (2) is exposed to potential losses or, less frequently, gains, arising from (a) possible claims against a company's resources due to future performance under contract terms, and (b) possible losses or likely gains from uncertainties that will ultimately be resolved when one or more future events that are deemed likely to occur do occur or fail to occur.", "label": "Commitments And Contingencies", "terseLabel": "Commitments and contingent liabilities (Note 18)" } } }, "localname": "CommitmentsAndContingencies", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_CommitmentsAndContingenciesDisclosureAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Commitments And Contingencies Disclosure [Abstract]" } } }, "localname": "CommitmentsAndContingenciesDisclosureAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_CommitmentsAndContingenciesDisclosureTextBlock": { "auth_ref": [ "r218", "r231" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for commitments and contingencies.", "label": "Commitments And Contingencies Disclosure [Text Block]", "terseLabel": "Commitments and Contingent Liabilities" } } }, "localname": "CommitmentsAndContingenciesDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilities" ], "xbrltype": "textBlockItemType" }, "us-gaap_CommonStockMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Stock that is subordinate to all other stock of the issuer.", "label": "Common Stock [Member]", "terseLabel": "Common Stock [Member]" } } }, "localname": "CommonStockMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "domainItemType" }, "us-gaap_CommonStockParOrStatedValuePerShare": { "auth_ref": [ "r33" ], "lang": { "en-US": { "role": { "documentation": "Face amount or stated value per share of common stock.", "label": "Common Stock Par Or Stated Value Per Share", "terseLabel": "Common stock, par value" } } }, "localname": "CommonStockParOrStatedValuePerShare", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetParenthetical" ], "xbrltype": "perShareItemType" }, "us-gaap_CommonStockSharesAuthorized": { "auth_ref": [ "r33" ], "lang": { "en-US": { "role": { "documentation": "The maximum number of common shares permitted to be issued by an entity's charter and bylaws.", "label": "Common Stock Shares Authorized", "terseLabel": "Common Stock, shares authorized" } } }, "localname": "CommonStockSharesAuthorized", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetParenthetical" ], "xbrltype": "sharesItemType" }, "us-gaap_CommonStockSharesIssued": { "auth_ref": [ "r33" ], "lang": { "en-US": { "role": { "documentation": "Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.", "label": "Common Stock Shares Issued", "terseLabel": "Common Stock, shares issued" } } }, "localname": "CommonStockSharesIssued", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetParenthetical" ], "xbrltype": "sharesItemType" }, "us-gaap_CommonStockValue": { "auth_ref": [ "r33" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10070.0, "parentTag": "us-gaap_StockholdersEquity", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.", "label": "Common Stock Value", "terseLabel": "Common Stock, $0.01 par value per share; 80,000,000 shares authorized; 23,556,317 and 23,321,087 shares issued" } } }, "localname": "CommonStockValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_CompensationAndRetirementDisclosureAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Compensation And Retirement Disclosure [Abstract]" } } }, "localname": "CompensationAndRetirementDisclosureAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_ComprehensiveIncomeNetOfTax": { "auth_ref": [ "r85", "r87", "r88" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.", "label": "Comprehensive Income Net Of Tax", "totalLabel": "Comprehensive (loss) income attributable to Koppers" } } }, "localname": "ComprehensiveIncomeNetOfTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest": { "auth_ref": [ "r85", "r87", "r338", "r339", "r346" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10020.0, "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income (loss) and other comprehensive income (loss), attributable to noncontrolling interests. Excludes changes in equity resulting from investments by owners and distributions to owners.", "label": "Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest", "terseLabel": "Comprehensive (loss) income attributable to noncontrolling interests" } } }, "localname": "ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest": { "auth_ref": [ "r85", "r87", "r337", "r346" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail": { "order": null, "parentTag": null, "root": true, "weight": null }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10010.0, "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.", "label": "Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest", "terseLabel": "Comprehensive (loss) income", "totalLabel": "Total comprehensive (loss) income" } } }, "localname": "ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_ContractWithCustomerAssetNetCurrent": { "auth_ref": [ "r249", "r250", "r253" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.", "label": "Contract With Customer Asset Net Current", "terseLabel": "Contract with customer, asset, net, current" } } }, "localname": "ContractWithCustomerAssetNetCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_CorporateNonSegmentMember": { "auth_ref": [ "r155" ], "lang": { "en-US": { "role": { "documentation": "Corporate headquarters or functional department that may not earn revenues or may earn revenues that are only incidental to the activities of the entity and is not considered an operating segment.", "label": "Corporate Non Segment [Member]", "terseLabel": "Corporate, Non-Segment [Member]" } } }, "localname": "CorporateNonSegmentMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_CostOfGoodsAndServicesSold": { "auth_ref": [ "r97" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10150.0, "parentTag": "us-gaap_OperatingIncomeLoss", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.", "label": "Cost Of Goods And Services Sold", "terseLabel": "Cost of sales" } } }, "localname": "CostOfGoodsAndServicesSold", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_CreditFacilityAxis": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Information by type of credit facility. Credit facilities provide capital to borrowers without the need to structure a loan for each borrowing.", "label": "Credit Facility [Axis]", "terseLabel": "Credit Facility" } } }, "localname": "CreditFacilityAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_CreditFacilityDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Type of credit facility. Credit facilities provide capital to borrowers without the need to structure a loan for each borrowing.", "label": "Credit Facility [Domain]", "terseLabel": "Credit Facility" } } }, "localname": "CreditFacilityDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_DebtDisclosureAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Debt Disclosure [Abstract]" } } }, "localname": "DebtDisclosureAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_DebtDisclosureTextBlock": { "auth_ref": [ "r239" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.", "label": "Debt Disclosure [Text Block]", "terseLabel": "Debt" } } }, "localname": "DebtDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebt" ], "xbrltype": "textBlockItemType" }, "us-gaap_DebtInstrumentAxis": { "auth_ref": [ "r28", "r29", "r30", "r413", "r414", "r428" ], "lang": { "en-US": { "role": { "documentation": "Information by type of debt instrument, including, but not limited to, draws against credit facilities.", "label": "Debt Instrument [Axis]", "terseLabel": "Debt Instrument" } } }, "localname": "DebtInstrumentAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DebtInstrumentDescriptionOfVariableRateBasis": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.", "label": "Debt Instrument Description Of Variable Rate Basis", "terseLabel": "Revolving credit facility, variable interest rate basis" } } }, "localname": "DebtInstrumentDescriptionOfVariableRateBasis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DebtInstrumentFairValue": { "auth_ref": [ "r384" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.", "label": "Debt Instrument Fair Value", "terseLabel": "Total debt" } } }, "localname": "DebtInstrumentFairValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DebtInstrumentLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Debt Instrument [Line Items]", "terseLabel": "Debt Instrument [Line Items]" } } }, "localname": "DebtInstrumentLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DebtInstrumentMaturityDate": { "auth_ref": [ "r54", "r380" ], "lang": { "en-US": { "role": { "documentation": "Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.", "label": "Debt Instrument Maturity Date", "terseLabel": "Debt maturity date" } } }, "localname": "DebtInstrumentMaturityDate", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "dateItemType" }, "us-gaap_DebtInstrumentNameDomain": { "auth_ref": [ "r57" ], "lang": { "en-US": { "role": { "documentation": "The name for the particular debt instrument or borrowing that distinguishes it from other debt instruments or borrowings, including draws against credit facilities.", "label": "Debt Instrument Name [Domain]", "terseLabel": "Debt Instrument, Name" } } }, "localname": "DebtInstrumentNameDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_DebtInstrumentPaymentTerms": { "auth_ref": [ "r55", "r425" ], "lang": { "en-US": { "role": { "documentation": "Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.", "label": "Debt Instrument Payment Terms", "terseLabel": "Senior notes, payment terms" } } }, "localname": "DebtInstrumentPaymentTerms", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DebtInstrumentRedemptionPricePercentage": { "auth_ref": [ "r426" ], "lang": { "en-US": { "role": { "documentation": "Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.", "label": "Debt Instrument Redemption Price Percentage", "terseLabel": "Debt instrument, redemption price percentage" } } }, "localname": "DebtInstrumentRedemptionPricePercentage", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "percentItemType" }, "us-gaap_DebtInstrumentTable": { "auth_ref": [ "r57", "r120", "r241", "r242", "r243", "r244", "r391", "r392", "r394", "r427" ], "lang": { "en-US": { "role": { "documentation": "A table or schedule providing information pertaining to long-term debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the company, if longer.", "label": "Debt Instrument [Table]", "terseLabel": "Debt Instrument [Table]" } } }, "localname": "DebtInstrumentTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet": { "auth_ref": [ "r237", "r393" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail": { "order": 10980.0, "parentTag": "us-gaap_LongTermDebt", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of unamortized debt discount (premium) and debt issuance costs.", "label": "Debt Instrument Unamortized Discount Premium And Debt Issuance Costs Net", "negatedLabel": "Less unamortized debt issuance costs" } } }, "localname": "DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount": { "auth_ref": [ "r56" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.", "label": "Debt Instrument Unused Borrowing Capacity Amount", "terseLabel": "Debt instrument, unused borrowing capacity" } } }, "localname": "DebtInstrumentUnusedBorrowingCapacityAmount", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DebtWeightedAverageInterestRate": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Weighted average interest rate of debt outstanding.", "label": "Debt Weighted Average Interest Rate", "terseLabel": "Debt, Weighted Average Interest Rate" } } }, "localname": "DebtWeightedAverageInterestRate", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "percentItemType" }, "us-gaap_DeferredIncomeTaxesAndTaxCredits": { "auth_ref": [ "r116" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10190.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of deferred income tax expense (benefit) and income tax credits.", "label": "Deferred Income Taxes And Tax Credits", "terseLabel": "Deferred income taxes" } } }, "localname": "DeferredIncomeTaxesAndTaxCredits", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_DeferredTaxAssetsNetNoncurrent": { "auth_ref": [ "r316", "r317", "r318", "r319", "r326" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10290.0, "parentTag": "us-gaap_Assets", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards classified as noncurrent.", "label": "Deferred Tax Assets Net Noncurrent", "terseLabel": "Deferred tax assets" } } }, "localname": "DeferredTaxAssetsNetNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_DeferredTaxLiabilitiesGrossNoncurrent": { "auth_ref": [ "r316", "r327" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10150.0, "parentTag": "us-gaap_Liabilities", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Gross amount of noncurrent deferred tax liabilities, which result from applying the applicable tax rate to taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax.", "label": "Deferred Tax Liabilities Gross Noncurrent", "terseLabel": "Deferred tax liabilities" } } }, "localname": "DeferredTaxLiabilitiesGrossNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses": { "auth_ref": [ "r265", "r275", "r276" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail": { "order": 10040.0, "parentTag": "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.", "label": "Defined Benefit Plan Amortization Of Gains Losses", "negatedLabel": "Amortization of net loss" } } }, "localname": "DefinedBenefitPlanAmortizationOfGainsLosses", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DefinedBenefitPlanDisclosureLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Defined Benefit Plan Disclosure [Line Items]", "terseLabel": "Defined Benefit Plan Disclosure [Line Items]" } } }, "localname": "DefinedBenefitPlanDisclosureLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets": { "auth_ref": [ "r264", "r274", "r276" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail": { "order": 10030.0, "parentTag": "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.", "label": "Defined Benefit Plan Expected Return On Plan Assets", "negatedLabel": "Expected return on plan assets" } } }, "localname": "DefinedBenefitPlanExpectedReturnOnPlanAssets", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DefinedBenefitPlanInterestCost": { "auth_ref": [ "r259", "r263", "r273", "r276" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail": { "order": 10020.0, "parentTag": "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of cost recognized for passage of time related to defined benefit plan.", "label": "Defined Benefit Plan Interest Cost", "terseLabel": "Interest cost" } } }, "localname": "DefinedBenefitPlanInterestCost", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost": { "auth_ref": [ "r261", "r271", "r276" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of net periodic benefit cost (credit) for defined benefit plan.", "label": "Defined Benefit Plan Net Periodic Benefit Cost", "totalLabel": "Net periodic benefit cost" } } }, "localname": "DefinedBenefitPlanNetPeriodicBenefitCost", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DefinedBenefitPlanServiceCost": { "auth_ref": [ "r258", "r262", "r272", "r276" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail": { "order": 10010.0, "parentTag": "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.", "label": "Defined Benefit Plan Service Cost", "terseLabel": "Service cost" } } }, "localname": "DefinedBenefitPlanServiceCost", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DefinedContributionPlanCostRecognized": { "auth_ref": [ "r277" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of cost for defined contribution plan.", "label": "Defined Contribution Plan Cost Recognized", "terseLabel": "Defined contribution plan expense" } } }, "localname": "DefinedContributionPlanCostRecognized", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansComponentsOfNetPeriodicBenefitCostForPensionPlansDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DepreciationAndAmortization": { "auth_ref": [ "r115", "r186" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10160.0, "parentTag": "us-gaap_OperatingIncomeLoss", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.", "label": "Depreciation And Amortization", "terseLabel": "Depreciation and amortization expense", "verboseLabel": "Depreciation and amortization" } } }, "localname": "DepreciationAndAmortization", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_DerivativeFairValueOfDerivativeNet": { "auth_ref": [ "r384" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Fair value of the assets less the liabilities of a derivative or group of derivatives.", "label": "Derivative Fair Value Of Derivative Net", "terseLabel": "Net Fair Value - (Liability) Asset", "verboseLabel": "Net Fair Value - (Liability) Asset" } } }, "localname": "DerivativeFairValueOfDerivativeNet", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Derivative Instruments And Hedging Activities Disclosure [Abstract]" } } }, "localname": "DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock": { "auth_ref": [ "r378" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.", "label": "Derivative Instruments And Hedging Activities Disclosure [Text Block]", "terseLabel": "Derivative Financial Instruments" } } }, "localname": "DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstruments" ], "xbrltype": "textBlockItemType" }, "us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis": { "auth_ref": [ "r357", "r361", "r367" ], "lang": { "en-US": { "role": { "documentation": "Information by type of hedging relationship.", "label": "Derivative Instruments Gain Loss By Hedging Relationship [Axis]", "terseLabel": "Hedging Relationship" } } }, "localname": "DerivativeInstrumentsGainLossByHedgingRelationshipAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Estimated period for the anticipated transfer of gain (loss), net, from accumulated other comprehensive income into earnings, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.", "label": "Derivative Instruments Gain Loss Reclassification From Accumulated O C I To Income Estimate Of Time To Transfer1", "terseLabel": "Unrealized losses, reclassification period" } } }, "localname": "DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsAdditionalInformationDetail" ], "xbrltype": "durationItemType" }, "us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred": { "auth_ref": [ "r377" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.", "label": "Derivative Instruments Gain Loss Reclassification From Accumulated O C I To Income Estimated Net Amount To Be Transferred", "negatedLabel": "Unrealized losses, net of tax benefit, expected to be reclassified from other comprehensive income into earnings" } } }, "localname": "DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet": { "auth_ref": [ "r366", "r368" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.", "label": "Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net", "terseLabel": "(Loss) gain from contracts not designated as hedges" } } }, "localname": "DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfLossGainFromContractNotDesignatedAsHedgesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DerivativeLiabilityNotionalAmount": { "auth_ref": [ "r352", "r353", "r355" ], "lang": { "en-US": { "role": { "documentation": "Nominal or face amount used to calculate payments on the derivative liability.", "label": "Derivative Liability Notional Amount", "terseLabel": "Copper Swap Contracts Units Outstanding" } } }, "localname": "DerivativeLiabilityNotionalAmount", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DerivativeLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Derivative [Line Items]", "terseLabel": "Derivative [Line Items]" } } }, "localname": "DerivativeLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfLossGainFromContractNotDesignatedAsHedgesDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DerivativeTable": { "auth_ref": [ "r122", "r351", "r354", "r355", "r357", "r359", "r364", "r367", "r371", "r372", "r374" ], "lang": { "en-US": { "role": { "documentation": "Schedule that describes and identifies a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.", "label": "Derivative [Table]", "terseLabel": "Derivative [Table]" } } }, "localname": "DerivativeTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfLossGainFromContractNotDesignatedAsHedgesDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DerivativesFairValueLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Derivatives Fair Value [Line Items]", "terseLabel": "Derivatives Fair Value [Line Items]" } } }, "localname": "DerivativesFairValueLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DesignatedAsHedgingInstrumentMember": { "auth_ref": [ "r357" ], "lang": { "en-US": { "role": { "documentation": "Derivative instrument designated as hedging instrument under Generally Accepted Accounting Principles (GAAP).", "label": "Designated As Hedging Instrument [Member]", "terseLabel": "Designated as Hedging Instrument [Member]" } } }, "localname": "DesignatedAsHedgingInstrumentMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock": { "auth_ref": [ "r313" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for share-based payment arrangement.", "label": "Disclosure Of Compensation Related Costs Share Based Payments [Text Block]", "terseLabel": "Stock-based Compensation" } } }, "localname": "DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensation" ], "xbrltype": "textBlockItemType" }, "us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]" } } }, "localname": "DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax": { "auth_ref": [ "r5", "r7", "r9", "r16" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of gain (loss) not previously recognized resulting from the disposal of a discontinued operation.", "label": "Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax", "terseLabel": "Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax" } } }, "localname": "DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation": { "auth_ref": [ "r6", "r7", "r8", "r9", "r11", "r16", "r320", "r330" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.", "label": "Discontinued Operation Tax Effect Of Discontinued Operation", "negatedLabel": "(Loss) income from discontinued operations, tax benefit (expense)" } } }, "localname": "DiscontinuedOperationTaxEffectOfDiscontinuedOperation", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnauditedParenthetical" ], "xbrltype": "monetaryItemType" }, "us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Discontinued Operations And Disposal Groups [Abstract]" } } }, "localname": "DiscontinuedOperationsAndDisposalGroupsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_DiscontinuedOperationsDisposedOfByMeansOtherThanSaleMember": { "auth_ref": [ "r3" ], "lang": { "en-US": { "role": { "documentation": "Component or group of components disposed of by means other than sale and representing a strategic shift that has or will have a major effect on operations and financial results.", "label": "Discontinued Operations Disposed Of By Means Other Than Sale [Member]", "terseLabel": "Discontinued Operations Disposed Of By Means Other Than Sale [Member]" } } }, "localname": "DiscontinuedOperationsDisposedOfByMeansOtherThanSaleMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "us-gaap_DiscontinuedOperationsHeldforsaleMember": { "auth_ref": [ "r2", "r4", "r15" ], "lang": { "en-US": { "role": { "documentation": "Component or group of components classified as held-for-sale and representing a strategic shift that has or will have a major effect on operations and financial results. Includes a business or nonprofit activity on acquisition classified as held-for-sale.", "label": "Discontinued Operations Heldforsale [Member]", "terseLabel": "Discontinued Operations, Held-for-sale [Member]" } } }, "localname": "DiscontinuedOperationsHeldforsaleMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail" ], "xbrltype": "domainItemType" }, "us-gaap_DisposalGroupClassificationAxis": { "auth_ref": [ "r15" ], "lang": { "en-US": { "role": { "documentation": "Information by disposal group classification.", "label": "Disposal Group Classification [Axis]", "terseLabel": "Disposal Group Classification" } } }, "localname": "DisposalGroupClassificationAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail" ], "xbrltype": "stringItemType" }, "us-gaap_DisposalGroupClassificationDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Component or group of components disposed of, including but not limited to, disposal group held-for-sale or disposed of by sale, disposed of by means other than sale, and discontinued operations.", "label": "Disposal Group Classification [Domain]", "terseLabel": "Disposal Group Classification" } } }, "localname": "DisposalGroupClassificationDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail" ], "xbrltype": "domainItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet": { "auth_ref": [ "r0", "r1", "r14", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10170.0, "parentTag": "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as accounts, notes and loans receivable attributable to disposal group held for sale or disposed of.", "label": "Disposal Group Including Discontinued Operation Accounts Notes And Loans Receivable Net", "terseLabel": "Accounts receivable" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent": { "auth_ref": [ "r0", "r1", "r14", "r185", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10060.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount classified as accounts payable attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Accounts Payable Current", "terseLabel": "Accounts payable" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent": { "auth_ref": [ "r0", "r1", "r14", "r185", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10070.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount classified as accrued liabilities attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Accrued Liabilities Current", "terseLabel": "Accrued liabilities" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent": { "auth_ref": [ "r0", "r1", "r14", "r15", "r183", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10120.0, "parentTag": "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10300.0, "parentTag": "us-gaap_Assets", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as assets attributable to disposal group held for sale or disposed of, expected to be disposed of after one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Assets Noncurrent", "terseLabel": "Non-current assets of discontinued operations held for sale", "totalLabel": "Total non-current assets held for sale" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents": { "auth_ref": [ "r0", "r1", "r14", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10160.0, "parentTag": "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as cash and cash equivalents attributable to disposal group held for sale or disposed of.", "label": "Disposal Group Including Discontinued Operation Cash And Cash Equivalents", "terseLabel": "Cash and cash equivalents" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold": { "auth_ref": [ "r12" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of costs of goods sold attributable to disposal group, including, but not limited to, discontinued operation.", "label": "Disposal Group Including Discontinued Operation Costs Of Goods Sold", "terseLabel": "Disposal Group, Including Discontinued Operation, Costs of Goods Sold" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredTaxLiabilities": { "auth_ref": [ "r0", "r1", "r14", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10030.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount classified as deferred tax liabilities attributable to disposal group held for sale or disposed of.", "label": "Disposal Group Including Discontinued Operation Deferred Tax Liabilities", "terseLabel": "Deferred tax liabilities" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationDeferredTaxLiabilities", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization": { "auth_ref": [ "r12" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of depreciation and amortization expense attributable to disposal group, including, but not limited to, discontinued operation.", "label": "Disposal Group Including Discontinued Operation Depreciation And Amortization", "terseLabel": "Depreciation and amortization expense" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsParentheticalDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationInventoryCurrent": { "auth_ref": [ "r0", "r1", "r14", "r185", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10190.0, "parentTag": "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as inventory attributable to disposal group, expected to be disposed of within one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Inventory Current", "terseLabel": "Inventories, net" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationInventoryCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss": { "auth_ref": [ "r12" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of operating income (loss) attributable to disposal group, including, but not limited to, discontinued operation.", "label": "Disposal Group Including Discontinued Operation Operating Income Loss", "terseLabel": "Operating (loss) profit" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetSalesAndOperatingLossProfitFromDiscontinuedOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsParentheticalDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets": { "auth_ref": [ "r0", "r1", "r14", "r185", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10220.0, "parentTag": "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as other assets attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Other Current Assets", "terseLabel": "Other current assets" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherCurrentLiabilities": { "auth_ref": [ "r0", "r1", "r14", "r185", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10100.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount classified as other liabilities attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Other Current Liabilities", "terseLabel": "Other current liabilities" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationOtherCurrentLiabilities", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets": { "auth_ref": [ "r0", "r1", "r14", "r183", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10150.0, "parentTag": "us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as other assets attributable to disposal group held for sale or disposed of, expected to be disposed of after one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Other Noncurrent Assets", "terseLabel": "Other assets" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities": { "auth_ref": [ "r0", "r1", "r14", "r183", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10050.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount classified as other liabilities attributable to disposal group held for sale or disposed of, expected to be disposed of beyond one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Other Noncurrent Liabilities", "terseLabel": "Other long-term liabilities" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent": { "auth_ref": [ "r0", "r1", "r14", "r185", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10200.0, "parentTag": "us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as property, plant and equipment attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Property Plant And Equipment Current", "terseLabel": "Property, plant and equipment, net" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent": { "auth_ref": [ "r0", "r1", "r14", "r183", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10130.0, "parentTag": "us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount classified as property, plant and equipment attributable to disposal group held for sale or disposed of, expected to be disposed of after one year or the normal operating cycle, if longer.", "label": "Disposal Group Including Discontinued Operation Property Plant And Equipment Noncurrent", "terseLabel": "Property, plant and equipment, net" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue": { "auth_ref": [ "r12" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of revenue attributable to disposal group, including, but not limited to, discontinued operation.", "label": "Disposal Group Including Discontinued Operation Revenue", "terseLabel": "Net sales" } } }, "localname": "DisposalGroupIncludingDiscontinuedOperationRevenue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetSalesAndOperatingLossProfitFromDiscontinuedOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsParentheticalDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock": { "auth_ref": [ "r17", "r193" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.", "label": "Disposal Groups Including Discontinued Operations Disclosure [Text Block]", "terseLabel": "Plant Closures and Divestitures" } } }, "localname": "DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestitures" ], "xbrltype": "textBlockItemType" }, "us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Name of disposal group.", "label": "Disposal Groups Including Discontinued Operations Name [Domain]", "terseLabel": "Disposal Group Name" } } }, "localname": "DisposalGroupsIncludingDiscontinuedOperationsNameDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "us-gaap_EarningsPerShareAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Earnings Per Share [Abstract]", "terseLabel": "Earnings (loss) per common share attributable to Koppers common shareholders:" } } }, "localname": "EarningsPerShareAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_EarningsPerShareBasic": { "auth_ref": [ "r94", "r124", "r128", "r130", "r131", "r132", "r135", "r423", "r440" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": null, "parentTag": null, "root": true, "weight": null } }, "lang": { "en-US": { "role": { "documentation": "The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.", "label": "Earnings Per Share Basic", "totalLabel": "(Loss) earnings per basic common share" } } }, "localname": "EarningsPerShareBasic", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "perShareItemType" }, "us-gaap_EarningsPerShareBasicAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Earnings Per Share Basic [Abstract]", "terseLabel": "Basic -" } } }, "localname": "EarningsPerShareBasicAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_EarningsPerShareBasicAndDilutedAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Earnings Per Share Basic And Diluted [Abstract]", "terseLabel": "Earnings per common share \u2013 continuing operations:" } } }, "localname": "EarningsPerShareBasicAndDilutedAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail" ], "xbrltype": "stringItemType" }, "us-gaap_EarningsPerShareDiluted": { "auth_ref": [ "r94", "r124", "r128", "r130", "r131", "r132", "r135", "r423", "r440" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": null, "parentTag": null, "root": true, "weight": null } }, "lang": { "en-US": { "role": { "documentation": "The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.", "label": "Earnings Per Share Diluted", "totalLabel": "(Loss) earnings per diluted common share" } } }, "localname": "EarningsPerShareDiluted", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "perShareItemType" }, "us-gaap_EarningsPerShareDilutedAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Earnings Per Share Diluted [Abstract]", "terseLabel": "Diluted -" } } }, "localname": "EarningsPerShareDilutedAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_EarningsPerShareDilutedOtherDisclosuresAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Earnings Per Share Diluted Other Disclosures [Abstract]", "terseLabel": "Other data:" } } }, "localname": "EarningsPerShareDilutedOtherDisclosuresAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail" ], "xbrltype": "stringItemType" }, "us-gaap_EarningsPerShareTextBlock": { "auth_ref": [ "r136" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for earnings per share.", "label": "Earnings Per Share [Text Block]", "terseLabel": "Earnings per Common Share" } } }, "localname": "EarningsPerShareTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShare" ], "xbrltype": "textBlockItemType" }, "us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents": { "auth_ref": [ "r387" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10040.0, "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of increase (decrease) from the effect of exchange rate changes on cash and cash equivalent balances held in foreign currencies.", "label": "Effect Of Exchange Rate On Cash And Cash Equivalents", "terseLabel": "Effect of exchange rate changes on cash" } } }, "localname": "EffectOfExchangeRateOnCashAndCashEquivalents", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_EffectiveIncomeTaxRateContinuingOperations": { "auth_ref": [ "r121", "r321", "r322" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail": { "order": null, "parentTag": null, "root": true, "weight": null } }, "lang": { "en-US": { "role": { "documentation": "Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.", "label": "Effective Income Tax Rate Continuing Operations", "terseLabel": "Estimated annual effective income tax rate", "totalLabel": "Estimated annual effective income tax rate" } } }, "localname": "EffectiveIncomeTaxRateContinuingOperations", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail" ], "xbrltype": "percentItemType" }, "us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate": { "auth_ref": [ "r321", "r322", "r328" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail": { "order": 10010.0, "parentTag": "us-gaap_EffectiveIncomeTaxRateContinuingOperations", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Percentage of domestic federal statutory tax rate applicable to pretax income (loss).", "label": "Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate", "terseLabel": "Federal income tax rate" } } }, "localname": "EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail" ], "xbrltype": "percentItemType" }, "us-gaap_EffectiveIncomeTaxRateReconciliationDeductions": { "auth_ref": [ "r321", "r322", "r328" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail": { "order": 10070.0, "parentTag": "us-gaap_EffectiveIncomeTaxRateContinuingOperations", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deductions. Including, but not limited to, extraterritorial income exclusion deduction, qualified production activity deduction, dividend deduction, deduction for dividend paid to employee stock ownership plan, Medicare prescription drug benefit subsidy deduction, and other deductions.", "label": "Effective Income Tax Rate Reconciliation Deductions", "terseLabel": "Interest expense deduction limitation" } } }, "localname": "EffectiveIncomeTaxRateReconciliationDeductions", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail" ], "xbrltype": "percentItemType" }, "us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential": { "auth_ref": [ "r321", "r322", "r328" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail": { "order": 10020.0, "parentTag": "us-gaap_EffectiveIncomeTaxRateContinuingOperations", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile.", "label": "Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential", "terseLabel": "Foreign earnings taxed at different rates" } } }, "localname": "EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail" ], "xbrltype": "percentItemType" }, "us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense": { "auth_ref": [ "r321", "r322", "r328" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail": { "order": 10030.0, "parentTag": "us-gaap_EffectiveIncomeTaxRateContinuingOperations", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible expenses.", "label": "Effective Income Tax Rate Reconciliation Nondeductible Expense", "terseLabel": "Nondeductible expenses" } } }, "localname": "EffectiveIncomeTaxRateReconciliationNondeductibleExpense", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail" ], "xbrltype": "percentItemType" }, "us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments": { "auth_ref": [ "r321", "r322", "r328" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail": { "order": 10080.0, "parentTag": "us-gaap_EffectiveIncomeTaxRateContinuingOperations", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments.", "label": "Effective Income Tax Rate Reconciliation Other Adjustments", "terseLabel": "Other" } } }, "localname": "EffectiveIncomeTaxRateReconciliationOtherAdjustments", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail" ], "xbrltype": "percentItemType" }, "us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes": { "auth_ref": [ "r321", "r322", "r328" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail": { "order": 10050.0, "parentTag": "us-gaap_EffectiveIncomeTaxRateContinuingOperations", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).", "label": "Effective Income Tax Rate Reconciliation State And Local Income Taxes", "terseLabel": "State income taxes, net of federal tax benefit" } } }, "localname": "EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail" ], "xbrltype": "percentItemType" }, "us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies": { "auth_ref": [ "r321", "r322", "r328" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail": { "order": 10060.0, "parentTag": "us-gaap_EffectiveIncomeTaxRateContinuingOperations", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to income tax contingencies. Includes, but not limited to, domestic tax contingency, foreign tax contingency, state and local tax contingency, and other contingencies.", "label": "Effective Income Tax Rate Reconciliation Tax Contingencies", "terseLabel": "Change in tax contingency reserves" } } }, "localname": "EffectiveIncomeTaxRateReconciliationTaxContingencies", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxesReconciledWithFederalStatutoryRateDetail" ], "xbrltype": "percentItemType" }, "us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]", "terseLabel": "Share-based Compensation Arrangement by Share-based Payment Award [Line Items]" } } }, "localname": "EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail" ], "xbrltype": "stringItemType" }, "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized": { "auth_ref": [ "r309" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of cost not yet recognized for nonvested award under share-based payment arrangement.", "label": "Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized", "terseLabel": "Future compensation expense related to non-vested stock-based compensation arrangements" } } }, "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1": { "auth_ref": [ "r309" ], "lang": { "en-US": { "role": { "documentation": "Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.", "label": "Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1", "terseLabel": "Future compensation expense, weighted-average expected period of recognition in months" } } }, "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "durationItemType" }, "us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense": { "auth_ref": [ "r308" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of tax benefit for recognition of expense of award under share-based payment arrangement.", "label": "Employee Service Share Based Compensation Tax Benefit From Compensation Expense", "terseLabel": "Less related income tax benefit" } } }, "localname": "EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_EmployeeSeveranceMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Termination of an employee associated with exit from or disposal of business activities or restructurings pursuant to a plan.", "label": "Employee Severance [Member]", "terseLabel": "Severance and Employee Benefits [Member]" } } }, "localname": "EmployeeSeveranceMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "domainItemType" }, "us-gaap_EmployeeStockOptionMember": { "auth_ref": [ "r306" ], "lang": { "en-US": { "role": { "documentation": "Share-based payment arrangement granting right, subject to vesting and other restrictions, to purchase or sell certain number of shares at predetermined price for specified period of time.", "label": "Employee Stock Option [Member]", "terseLabel": "Employee Stock Option [Member]" } } }, "localname": "EmployeeStockOptionMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Entity Wide Information Revenue From External Customer [Line Items]", "verboseLabel": "Revenues from external customers:" } } }, "localname": "EntityWideInformationRevenueFromExternalCustomerLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_EnvironmentalRemediationSiteAxis": { "auth_ref": [ "r200", "r203", "r205", "r207", "r230" ], "lang": { "en-US": { "role": { "documentation": "Information by location or named area designated for environmental remediation.", "label": "Environmental Remediation Site [Axis]", "terseLabel": "Environmental Remediation Site" } } }, "localname": "EnvironmentalRemediationSiteAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_EnvironmentalRemediationSiteDomain": { "auth_ref": [ "r200" ], "lang": { "en-US": { "role": { "documentation": "Location or named area designated for environmental remediation.", "label": "Environmental Remediation Site [Domain]", "terseLabel": "Environmental Remediation Site" } } }, "localname": "EnvironmentalRemediationSiteDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "us-gaap_EquityAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Equity [Abstract]" } } }, "localname": "EquityAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_EquityComponentDomain": { "auth_ref": [ "r240" ], "lang": { "en-US": { "role": { "documentation": "Components of equity are the parts of the total Equity balance including that which is allocated to common, preferred, treasury stock, retained earnings, etc.", "label": "Equity Component [Domain]", "terseLabel": "Equity Component" } } }, "localname": "EquityComponentDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "domainItemType" }, "us-gaap_EquityMethodInvestmentOwnershipPercentage": { "auth_ref": [ "r164" ], "lang": { "en-US": { "role": { "documentation": "The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.", "label": "Equity Method Investment Ownership Percentage", "terseLabel": "Ownership percentage" } } }, "localname": "EquityMethodInvestmentOwnershipPercentage", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "percentItemType" }, "us-gaap_EstimateOfFairValueFairValueDisclosureMember": { "auth_ref": [ "r384" ], "lang": { "en-US": { "role": { "documentation": "Measured as an estimate of fair value.", "label": "Estimate Of Fair Value Fair Value Disclosure [Member]", "terseLabel": "Fair Value [Member]" } } }, "localname": "EstimateOfFairValueFairValueDisclosureMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_FacilityClosingMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Closing of a facility associated with exit from or disposal of business activities or restructurings pursuant to a plan.", "label": "Facility Closing [Member]", "terseLabel": "Asset Retirement [Member]" } } }, "localname": "FacilityClosingMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "domainItemType" }, "us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]", "terseLabel": "Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]" } } }, "localname": "FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_FairValueByBalanceSheetGroupingTable": { "auth_ref": [ "r379", "r385", "r386" ], "lang": { "en-US": { "role": { "documentation": "Disclosure of information about the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.", "label": "Fair Value By Balance Sheet Grouping [Table]", "terseLabel": "Fair Value By Balance Sheet Grouping [Table]" } } }, "localname": "FairValueByBalanceSheetGroupingTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_FairValueByBalanceSheetGroupingTextBlock": { "auth_ref": [ "r379", "r385" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.", "label": "Fair Value By Balance Sheet Grouping [Text Block]", "terseLabel": "Schedule of Company's Financial Instruments" } } }, "localname": "FairValueByBalanceSheetGroupingTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_FairValueByMeasurementBasisAxis": { "auth_ref": [ "r379", "r381" ], "lang": { "en-US": { "role": { "documentation": "Information by measurement basis.", "label": "Fair Value By Measurement Basis [Axis]", "terseLabel": "Measurement Basis" } } }, "localname": "FairValueByMeasurementBasisAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_FairValueDisclosureItemAmountsDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Measurement basis, for example, but not limited to, reported value, fair value, portion at fair value, portion at other than fair value.", "label": "Fair Value Disclosure Item Amounts [Domain]", "terseLabel": "Fair Value Measurement" } } }, "localname": "FairValueDisclosureItemAmountsDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_FairValueDisclosuresAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Fair Value Disclosures [Abstract]" } } }, "localname": "FairValueDisclosuresAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_FairValueMeasurementInputsDisclosureTextBlock": { "auth_ref": [ "r382" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure of the fair value measurement of assets and liabilities, which includes financial instruments measured at fair value that are classified in shareholders' equity, which may be measured on a recurring or nonrecurring basis.", "label": "Fair Value Measurement Inputs Disclosure [Text Block]", "terseLabel": "Fair Value Measurements" } } }, "localname": "FairValueMeasurementInputsDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurements" ], "xbrltype": "textBlockItemType" }, "us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable": { "auth_ref": [ "r360", "r364", "r373" ], "lang": { "en-US": { "role": { "documentation": "Schedule that discloses the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position.", "label": "Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table]", "terseLabel": "Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table]" } } }, "localname": "FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_FinancialInstrumentAxis": { "auth_ref": [ "r167", "r168", "r169", "r170", "r171", "r172", "r173", "r174", "r175" ], "lang": { "en-US": { "role": { "documentation": "Information by type of financial instrument.", "label": "Financial Instrument [Axis]", "terseLabel": "Financial Instrument" } } }, "localname": "FinancialInstrumentAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfLossGainFromContractNotDesignatedAsHedgesDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Financial Instruments Financial Assets Balance Sheet Groupings [Abstract]", "terseLabel": "Financial assets:" } } }, "localname": "FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]", "terseLabel": "Financial liabilities:" } } }, "localname": "FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_FiniteLivedIntangibleAssetsNet": { "auth_ref": [ "r182" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10280.0, "parentTag": "us-gaap_Assets", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.", "label": "Finite Lived Intangible Assets Net", "terseLabel": "Intangible assets, net" } } }, "localname": "FiniteLivedIntangibleAssetsNet", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue": { "auth_ref": [ "r362" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Fair value as of the balance sheet date of all foreign currency derivative assets not designated as hedging instruments.", "label": "Foreign Currency Derivative Instruments Not Designated As Hedging Instruments Asset At Fair Value", "terseLabel": "Not designated gross derivative assets" } } }, "localname": "ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet": { "auth_ref": [ "r350" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Fair value as of the balance sheet date of all foreign currency derivatives not designated as hedging instruments.", "label": "Foreign Currency Derivative Instruments Not Designated As Hedging Instruments At Fair Value Net", "terseLabel": "Not designated net fair value - net liability" } } }, "localname": "ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue": { "auth_ref": [ "r362" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Fair value as of the balance sheet date of all foreign currency derivative liabilities not designated as hedging instruments.", "label": "Foreign Currency Derivative Instruments Not Designated As Hedging Instruments Liability At Fair Value", "negatedLabel": "Not designated gross derivative liability" } } }, "localname": "ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_ForwardContractsMember": { "auth_ref": [ "r369" ], "lang": { "en-US": { "role": { "documentation": "Contracts negotiated between two parties to purchase and sell a specific quantity of a financial instrument, foreign currency, or commodity at a price specified at origination of the contract, with delivery and settlement at a specified future date.", "label": "Forward Contracts [Member]", "terseLabel": "Forward Contracts [Member]" } } }, "localname": "ForwardContractsMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_Goodwill": { "auth_ref": [ "r179", "r180" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10270.0, "parentTag": "us-gaap_Assets", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.", "label": "Goodwill", "terseLabel": "Goodwill" } } }, "localname": "Goodwill", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_HedgingDesignationAxis": { "auth_ref": [ "r357", "r370" ], "lang": { "en-US": { "role": { "documentation": "Information by designation of purpose of derivative instrument.", "label": "Hedging Designation [Axis]", "terseLabel": "Hedging Designation" } } }, "localname": "HedgingDesignationAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_HedgingDesignationDomain": { "auth_ref": [ "r357" ], "lang": { "en-US": { "role": { "documentation": "Designation of purpose of derivative instrument.", "label": "Hedging Designation [Domain]", "terseLabel": "Hedging Designation" } } }, "localname": "HedgingDesignationDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_HedgingRelationshipDomain": { "auth_ref": [ "r357" ], "lang": { "en-US": { "role": { "documentation": "Nature or intent of a hedge.", "label": "Hedging Relationship [Domain]", "terseLabel": "Hedging Relationship" } } }, "localname": "HedgingRelationshipDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_IncomeLossFromContinuingOperations": { "auth_ref": [ "r96", "r116", "r132", "r336" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail": { "order": 10050.0, "parentTag": "us-gaap_NetIncomeLoss", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of income (loss) from continuing operations attributable to the parent.", "label": "Income Loss From Continuing Operations", "terseLabel": "Income from continuing operations attributable to Koppers" } } }, "localname": "IncomeLossFromContinuingOperations", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest": { "auth_ref": [ "r91", "r124", "r411", "r420", "r441" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10120.0, "parentTag": "us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.", "label": "Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest", "terseLabel": "Income from continuing operations before income taxes" } } }, "localname": "IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest": { "auth_ref": [ "r337" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10090.0, "parentTag": "us-gaap_ProfitLoss", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of income (loss) from continuing operations including portion attributable to the noncontrolling interest.", "label": "Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest", "totalLabel": "Income from continuing operations" } } }, "localname": "IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncomeLossFromContinuingOperationsPerBasicShare": { "auth_ref": [ "r89", "r94", "r128", "r130", "r131", "r419", "r421", "r423", "r437" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10050.0, "parentTag": "us-gaap_EarningsPerShareBasic", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.", "label": "Income Loss From Continuing Operations Per Basic Share", "terseLabel": "Continuing operations", "verboseLabel": "Basic earnings per common share" } } }, "localname": "IncomeLossFromContinuingOperationsPerBasicShare", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "perShareItemType" }, "us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare": { "auth_ref": [ "r89", "r94", "r128", "r130", "r131", "r132", "r423", "r437", "r440" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10030.0, "parentTag": "us-gaap_EarningsPerShareDiluted", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.", "label": "Income Loss From Continuing Operations Per Diluted Share", "terseLabel": "Continuing operations", "verboseLabel": "Diluted earnings per common share" } } }, "localname": "IncomeLossFromContinuingOperationsPerDilutedShare", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "perShareItemType" }, "us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax": { "auth_ref": [ "r5", "r6", "r7", "r8", "r9", "r16", "r94", "r438" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10100.0, "parentTag": "us-gaap_ProfitLoss", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.", "label": "Income Loss From Discontinued Operations Net Of Tax", "terseLabel": "(Loss) income from discontinued operations, net of tax benefit (expense) of $0.8 and $(1.1)" } } }, "localname": "IncomeLossFromDiscontinuedOperationsNetOfTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToNoncontrollingInterest": { "auth_ref": [ "r5", "r6", "r7", "r8", "r9", "r11", "r16", "r334", "r337" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail": { "order": 10040.0, "parentTag": "us-gaap_NetIncomeLoss", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of income (loss) from a discontinued operation attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.", "label": "Income Loss From Discontinued Operations Net Of Tax Attributable To Noncontrolling Interest", "negatedLabel": "Non-controlling loss (income) from discontinued operations" } } }, "localname": "IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToNoncontrollingInterest", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity": { "auth_ref": [ "r5", "r6", "r7", "r8", "r9", "r11", "r16", "r337" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail": { "order": 10030.0, "parentTag": "us-gaap_NetIncomeLoss", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of income (loss) from a discontinued operation attributable to the parent. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.", "label": "Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity", "terseLabel": "(Loss) income from discontinued operations" } } }, "localname": "IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare": { "auth_ref": [ "r92", "r94", "r129", "r130", "r131", "r423", "r438", "r440" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10060.0, "parentTag": "us-gaap_EarningsPerShareBasic", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Per basic share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation.", "label": "Income Loss From Discontinued Operations Net Of Tax Per Basic Share", "terseLabel": "Discontinued operations" } } }, "localname": "IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "perShareItemType" }, "us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare": { "auth_ref": [ "r129", "r130", "r131", "r347" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10040.0, "parentTag": "us-gaap_EarningsPerShareDiluted", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Per diluted share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation.", "label": "Income Loss From Discontinued Operations Net Of Tax Per Diluted Share", "terseLabel": "Discontinued operations" } } }, "localname": "IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "perShareItemType" }, "us-gaap_IncomeStatementAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Income Statement [Abstract]" } } }, "localname": "IncomeStatementAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Information by name of disposal group.", "label": "Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Axis]", "terseLabel": "Disposal Group Name" } } }, "localname": "IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_IncomeStatementLocationAxis": { "auth_ref": [ "r190" ], "lang": { "en-US": { "role": { "documentation": "Information by location in the income statement.", "label": "Income Statement Location [Axis]", "terseLabel": "Income Statement Location" } } }, "localname": "IncomeStatementLocationAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail" ], "xbrltype": "stringItemType" }, "us-gaap_IncomeStatementLocationDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Location in the income statement.", "label": "Income Statement Location [Domain]", "terseLabel": "Income Statement Location" } } }, "localname": "IncomeStatementLocationDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail" ], "xbrltype": "domainItemType" }, "us-gaap_IncomeTaxDisclosureAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Income Tax Disclosure [Abstract]" } } }, "localname": "IncomeTaxDisclosureAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_IncomeTaxDisclosureTextBlock": { "auth_ref": [ "r331" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.", "label": "Income Tax Disclosure [Text Block]", "terseLabel": "Income Taxes" } } }, "localname": "IncomeTaxDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxes" ], "xbrltype": "textBlockItemType" }, "us-gaap_IncomeTaxExpenseBenefit": { "auth_ref": [ "r118", "r146", "r329" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10130.0, "parentTag": "us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.", "label": "Income Tax Expense Benefit", "terseLabel": "Income tax provision" } } }, "localname": "IncomeTaxExpenseBenefit", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance": { "auth_ref": [ "r315", "r321", "r322" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.", "label": "Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance", "terseLabel": "Effective income tax rate reconciliation, change in deferred tax assets valuation allowance, amount" } } }, "localname": "IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncomeTaxReconciliationPriorYearIncomeTaxes": { "auth_ref": [ "r321", "r322" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to revisions of previously reported income tax expense (benefit).", "label": "Income Tax Reconciliation Prior Year Income Taxes", "terseLabel": "Effective income tax rate reconciliation, prior year income taxes, amount" } } }, "localname": "IncomeTaxReconciliationPriorYearIncomeTaxes", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncomeTaxesReceivable": { "auth_ref": [ "r62", "r417", "r436" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10340.0, "parentTag": "us-gaap_AssetsCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Carrying amount due within one year of the balance sheet date (or one operating cycle, if longer) from tax authorities as of the balance sheet date representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes.", "label": "Income Taxes Receivable", "terseLabel": "Income tax receivable" } } }, "localname": "IncomeTaxesReceivable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncreaseDecreaseInAccountsPayable": { "auth_ref": [ "r114" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10250.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The increase (decrease) during the reporting period in the aggregate amount of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.", "label": "Increase Decrease In Accounts Payable", "terseLabel": "Accounts payable" } } }, "localname": "IncreaseDecreaseInAccountsPayable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncreaseDecreaseInAccountsReceivable": { "auth_ref": [ "r114" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10230.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The increase (decrease) during the reporting period in amount due within one year (or one business cycle) from customers for the credit sale of goods and services.", "label": "Increase Decrease In Accounts Receivable", "negatedLabel": "Accounts receivable" } } }, "localname": "IncreaseDecreaseInAccountsReceivable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncreaseDecreaseInAccruedLiabilities": { "auth_ref": [ "r114" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10260.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The increase (decrease) during the reporting period in the aggregate amount of expenses incurred but not yet paid.", "label": "Increase Decrease In Accrued Liabilities", "terseLabel": "Accrued liabilities" } } }, "localname": "IncreaseDecreaseInAccruedLiabilities", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncreaseDecreaseInInventories": { "auth_ref": [ "r114" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10240.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities.", "label": "Increase Decrease In Inventories", "negatedLabel": "Inventories" } } }, "localname": "IncreaseDecreaseInInventories", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncreaseDecreaseInOperatingCapitalAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Increase Decrease In Operating Capital [Abstract]", "terseLabel": "Changes in working capital:" } } }, "localname": "IncreaseDecreaseInOperatingCapitalAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet": { "auth_ref": [ "r114" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10270.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of increase (decrease) in operating assets after deduction of operating liabilities classified as other.", "label": "Increase Decrease In Other Operating Capital Net", "negatedLabel": "Other working capital" } } }, "localname": "IncreaseDecreaseInOtherOperatingCapitalNet", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IncreaseDecreaseInOtherOperatingLiabilities": { "auth_ref": [ "r114" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10210.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of increase (decrease) in operating liabilities classified as other.", "label": "Increase Decrease In Other Operating Liabilities", "terseLabel": "Change in other liabilities" } } }, "localname": "IncreaseDecreaseInOtherOperatingLiabilities", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IndemnificationGuaranteeMember": { "auth_ref": [ "r232", "r235" ], "lang": { "en-US": { "role": { "documentation": "An agreement (contract) that contingently requires the guarantor to make payments to the guaranteed party in compensation for that party's or parties' loss or injury attributable to specified events or actions, such as a patent infringement action against an entity that relied on certain representations as to ownership rights made by a software vendor.", "label": "Indemnification Guarantee [Member]", "terseLabel": "Indemnification Agreement [Member]" } } }, "localname": "IndemnificationGuaranteeMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "us-gaap_InterestExpense": { "auth_ref": [ "r90", "r145", "r390", "r393", "r424" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10110.0, "parentTag": "us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of the cost of borrowed funds accounted for as interest expense.", "label": "Interest Expense", "terseLabel": "Interest expense" } } }, "localname": "InterestExpense", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_IntersegmentEliminationMember": { "auth_ref": [ "r151" ], "lang": { "en-US": { "role": { "documentation": "Eliminating entries used in operating segment consolidation.", "label": "Intersegment Elimination [Member]", "terseLabel": "Intersegment [Member]" } } }, "localname": "IntersegmentEliminationMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_InventoryCurrentTable": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Disclosure of information about inventory expected to be sold or consumed within one year or operating cycle, if longer.", "label": "Inventory Current [Table]", "terseLabel": "Inventory Current [Table]" } } }, "localname": "InventoryCurrentTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesParentheticalDetail" ], "xbrltype": "stringItemType" }, "us-gaap_InventoryDisclosureAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Inventory Disclosure [Abstract]" } } }, "localname": "InventoryDisclosureAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_InventoryDisclosureTextBlock": { "auth_ref": [ "r178" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for inventory. Includes, but is not limited to, the basis of stating inventory, the method of determining inventory cost, the classes of inventory, and the nature of the cost elements included in inventory.", "label": "Inventory Disclosure [Text Block]", "terseLabel": "Inventories" } } }, "localname": "InventoryDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventories" ], "xbrltype": "textBlockItemType" }, "us-gaap_InventoryFinishedGoods": { "auth_ref": [ "r64" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail": { "order": 10050.0, "parentTag": "us-gaap_InventoryGross", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.", "label": "Inventory Finished Goods", "terseLabel": "Finished goods" } } }, "localname": "InventoryFinishedGoods", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_InventoryGross": { "auth_ref": [ "r67" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail": { "order": 10010.0, "parentTag": "us-gaap_InventoryNet", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.", "label": "Inventory Gross", "totalLabel": "Inventories, gross" } } }, "localname": "InventoryGross", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_InventoryLIFOReserve": { "auth_ref": [ "r68" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail": { "order": 10020.0, "parentTag": "us-gaap_InventoryNet", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount by which inventory stated at last-in first-out (LIFO) is less than (in excess of) inventory stated at other inventory cost methods.", "label": "Inventory L I F O Reserve", "terseLabel": "Less revaluation to LIFO" } } }, "localname": "InventoryLIFOReserve", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_InventoryLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Inventory [Line Items]", "terseLabel": "Inventory [Line Items]" } } }, "localname": "InventoryLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesParentheticalDetail" ], "xbrltype": "stringItemType" }, "us-gaap_InventoryNet": { "auth_ref": [ "r20", "r67", "r177" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail": { "order": null, "parentTag": null, "root": true, "weight": null }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10350.0, "parentTag": "us-gaap_AssetsCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.", "label": "Inventory Net", "terseLabel": "Inventories, net", "totalLabel": "Net" } } }, "localname": "InventoryNet", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_InventoryRawMaterials": { "auth_ref": [ "r66" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail": { "order": 10030.0, "parentTag": "us-gaap_InventoryGross", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer.", "label": "Inventory Raw Materials", "terseLabel": "Raw materials" } } }, "localname": "InventoryRawMaterials", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_InventoryWorkInProcess": { "auth_ref": [ "r65" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail": { "order": 10040.0, "parentTag": "us-gaap_InventoryGross", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.", "label": "Inventory Work In Process", "terseLabel": "Work in process" } } }, "localname": "InventoryWorkInProcess", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesComponentsOfNetInventoriesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LandMember": { "auth_ref": [ "r254" ], "lang": { "en-US": { "role": { "documentation": "Part of earth's surface not covered by water.", "label": "Land [Member]", "terseLabel": "Land [Member]" } } }, "localname": "LandMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail" ], "xbrltype": "domainItemType" }, "us-gaap_LeasesAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Leases [Abstract]" } } }, "localname": "LeasesAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_LeasesOfLesseeDisclosureTextBlock": { "auth_ref": [ "r396" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for lessee entity's leasing arrangements including, but not limited to, all of the following: (a.) The basis on which contingent rental payments are determined, (b.) The existence and terms of renewal or purchase options and escalation clauses, (c.) Restrictions imposed by lease agreements, such as those concerning dividends, additional debt, and further leasing.", "label": "Leases Of Lessee Disclosure [Text Block]", "terseLabel": "Leases" } } }, "localname": "LeasesOfLesseeDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeases" ], "xbrltype": "textBlockItemType" }, "us-gaap_LesseeOperatingLeaseDescriptionAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Lessee Operating Lease Description [Abstract]", "terseLabel": "Operating leases:" } } }, "localname": "LesseeOperatingLeaseDescriptionAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail" ], "xbrltype": "stringItemType" }, "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue": { "auth_ref": [ "r406" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail": { "order": null, "parentTag": null, "root": true, "weight": null }, "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail2": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease.", "label": "Lessee Operating Lease Liability Payments Due", "totalLabel": "Total lease payments" } } }, "localname": "LesseeOperatingLeaseLiabilityPaymentsDue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive": { "auth_ref": [ "r406" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail": { "order": 10060.0, "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease, due after fifth fiscal year following latest fiscal year.", "label": "Lessee Operating Lease Liability Payments Due After Year Five", "terseLabel": "Thereafter" } } }, "localname": "LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive": { "auth_ref": [ "r406" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail": { "order": 10050.0, "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fifth fiscal year following latest fiscal year.", "label": "Lessee Operating Lease Liability Payments Due Year Five", "terseLabel": "2024" } } }, "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearFive", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour": { "auth_ref": [ "r406" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail": { "order": 10040.0, "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fourth fiscal year following latest fiscal year.", "label": "Lessee Operating Lease Liability Payments Due Year Four", "terseLabel": "2023" } } }, "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearFour", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree": { "auth_ref": [ "r406" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail": { "order": 10030.0, "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease, due in third fiscal year following latest fiscal year.", "label": "Lessee Operating Lease Liability Payments Due Year Three", "terseLabel": "2022" } } }, "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearThree", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo": { "auth_ref": [ "r406" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail": { "order": 10020.0, "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease, due in second fiscal year following latest fiscal year.", "label": "Lessee Operating Lease Liability Payments Due Year Two", "terseLabel": "2021" } } }, "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearTwo", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear": { "auth_ref": [ "r406" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail": { "order": 10010.0, "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease having an initial or remaining lease term in excess of one year due in remainder of fiscal year following latest fiscal year.", "label": "Lessee Operating Lease Liability Payments Remainder Of Fiscal Year", "terseLabel": "2020" } } }, "localname": "LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount": { "auth_ref": [ "r406" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail2": { "order": 10010.0, "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.", "label": "Lessee Operating Lease Liability Undiscounted Excess Amount", "negatedLabel": "Less: Interest" } } }, "localname": "LesseeOperatingLeaseLiabilityUndiscountedExcessAmount", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LettersOfCreditOutstandingAmount": { "auth_ref": [], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.", "label": "Letters Of Credit Outstanding Amount", "terseLabel": "Letters of credit, amount outstanding" } } }, "localname": "LettersOfCreditOutstandingAmount", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_Liabilities": { "auth_ref": [ "r51" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10010.0, "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.", "label": "Liabilities", "totalLabel": "Total liabilities" } } }, "localname": "Liabilities", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_LiabilitiesAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Liabilities [Abstract]", "terseLabel": "Liabilities" } } }, "localname": "LiabilitiesAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "stringItemType" }, "us-gaap_LiabilitiesAndStockholdersEquity": { "auth_ref": [ "r39", "r416", "r433" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any.", "label": "Liabilities And Stockholders Equity", "totalLabel": "Total liabilities and equity" } } }, "localname": "LiabilitiesAndStockholdersEquity", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_LiabilitiesCurrent": { "auth_ref": [ "r53" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10120.0, "parentTag": "us-gaap_Liabilities", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer.", "label": "Liabilities Current", "totalLabel": "Total current liabilities" } } }, "localname": "LiabilitiesCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation": { "auth_ref": [ "r0", "r1", "r14", "r15", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount classified as liabilities attributable to disposal group held for sale or disposed of.", "label": "Liabilities Of Disposal Group Including Discontinued Operation", "totalLabel": "Total liabilities held for sale" } } }, "localname": "LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Liabilities Of Disposal Group Including Discontinued Operation [Abstract]", "terseLabel": "Liabilities" } } }, "localname": "LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail" ], "xbrltype": "stringItemType" }, "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent": { "auth_ref": [ "r0", "r1", "r14", "r15", "r185", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10010.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10230.0, "parentTag": "us-gaap_LiabilitiesCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount classified as liabilities attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer.", "label": "Liabilities Of Disposal Group Including Discontinued Operation Current", "terseLabel": "Liabilities of discontinued operations held for sale", "totalLabel": "Total current liabilities held for sale" } } }, "localname": "LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent": { "auth_ref": [ "r0", "r1", "r14", "r15", "r183", "r191" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail": { "order": 10020.0, "parentTag": "us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10170.0, "parentTag": "us-gaap_Liabilities", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount classified as liabilities attributable to disposal group held for sale or disposed of, expected to be disposed of beyond one year or the normal operating cycle, if longer.", "label": "Liabilities Of Disposal Group Including Discontinued Operation Noncurrent", "terseLabel": "Non-current liabilities of discontinued operations held for sale", "totalLabel": "Total non-current liabilities held for sale" } } }, "localname": "LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfCarryingAmountOfAssetsAndLiabilitiesByMajorClassClassifiedAsHeldForSaleDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity": { "auth_ref": [ "r49" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.", "label": "Line Of Credit Facility Maximum Borrowing Capacity", "terseLabel": "Revolving credit facility" } } }, "localname": "LineOfCreditFacilityMaximumBorrowingCapacity", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LongTermDebt": { "auth_ref": [ "r30", "r238", "r414", "r430" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.", "label": "Long Term Debt", "totalLabel": "Debt" } } }, "localname": "LongTermDebt", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LongTermDebtCurrent": { "auth_ref": [ "r50" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail": { "order": 10970.0, "parentTag": "us-gaap_LongTermDebt", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10220.0, "parentTag": "us-gaap_LiabilitiesCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.", "label": "Long Term Debt Current", "terseLabel": "Current maturities of long-term debt", "verboseLabel": "Less short-term debt and current maturities of long-term debt" } } }, "localname": "LongTermDebtCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_LongTermDebtNoncurrent": { "auth_ref": [ "r57" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail": { "order": 10990.0, "parentTag": "us-gaap_LongTermDebt", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10130.0, "parentTag": "us-gaap_Liabilities", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.", "label": "Long Term Debt Noncurrent", "terseLabel": "Long-term debt" } } }, "localname": "LongTermDebtNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_LongtermDebtTypeAxis": { "auth_ref": [ "r57" ], "lang": { "en-US": { "role": { "documentation": "Information by type of long-term debt.", "label": "Longterm Debt Type [Axis]", "terseLabel": "Long-term Debt, Type" } } }, "localname": "LongtermDebtTypeAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_LongtermDebtTypeDomain": { "auth_ref": [ "r57", "r236" ], "lang": { "en-US": { "role": { "documentation": "Type of long-term debt arrangement, such as notes, line of credit, commercial paper, asset-based financing, project financing, letter of credit financing. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the company, if longer.", "label": "Longterm Debt Type [Domain]", "terseLabel": "Long-term Debt, Type" } } }, "localname": "LongtermDebtTypeDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_LossContingenciesByNatureOfContingencyAxis": { "auth_ref": [ "r220", "r221", "r222", "r224", "r225", "r226", "r228", "r233", "r234" ], "lang": { "en-US": { "role": { "documentation": "Information by type of existing condition, situation, or set of circumstances involving uncertainty as to possible loss to an enterprise that will ultimately be resolved when one or more future events occur or fail to occur.", "label": "Loss Contingencies By Nature Of Contingency [Axis]", "terseLabel": "Loss Contingency Nature" } } }, "localname": "LossContingenciesByNatureOfContingencyAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_LossContingenciesLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Loss Contingencies [Line Items]", "terseLabel": "Loss Contingencies [Line Items]" } } }, "localname": "LossContingenciesLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_LossContingenciesTable": { "auth_ref": [ "r220", "r221", "r222", "r224", "r225", "r226", "r228", "r233", "r234" ], "lang": { "en-US": { "role": { "documentation": "Discloses the specific components (such as the nature, name, and date) of the loss contingency and gives an estimate of the possible loss or range of loss, or states that a reasonable estimate cannot be made. Excludes environmental contingencies, warranties and unconditional purchase obligations.", "label": "Loss Contingencies [Table]", "terseLabel": "Loss Contingencies [Table]" } } }, "localname": "LossContingenciesTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_LossContingencyAccrualAtCarryingValue": { "auth_ref": [ "r220" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of loss contingency liability.", "label": "Loss Contingency Accrual At Carrying Value", "terseLabel": "Reserve for legal proceedings" } } }, "localname": "LossContingencyAccrualAtCarryingValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LossContingencyDamagesSoughtValue": { "auth_ref": [ "r220", "r223", "r227" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The value (monetary amount) of the award the plaintiff seeks in the legal matter.", "label": "Loss Contingency Damages Sought Value", "terseLabel": "Compensatory damages" } } }, "localname": "LossContingencyDamagesSoughtValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_LossContingencyNatureDomain": { "auth_ref": [ "r220", "r221", "r222", "r224", "r225", "r226", "r228", "r233", "r234" ], "lang": { "en-US": { "role": { "documentation": "An existing condition, situation, or set of circumstances involving uncertainty as to possible loss to an enterprise that will ultimately be resolved when one or more future events occur or fail to occur. Resolution of the uncertainty may confirm the incurrence of a loss or impairment of an asset or the incurrence of a liability.", "label": "Loss Contingency Nature [Domain]", "terseLabel": "Loss Contingency, Nature" } } }, "localname": "LossContingencyNatureDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "us-gaap_LossContingencyNumberOfPlaintiffs": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Number of plaintiffs that have filed claims pertaining to a loss contingency.", "label": "Loss Contingency Number Of Plaintiffs", "terseLabel": "Number of plaintiffs" } } }, "localname": "LossContingencyNumberOfPlaintiffs", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "integerItemType" }, "us-gaap_LossContingencyPendingClaimsNumber": { "auth_ref": [ "r223" ], "lang": { "en-US": { "role": { "documentation": "Number of pending claims pertaining to a loss contingency.", "label": "Loss Contingency Pending Claims Number", "terseLabel": "Number of cases" } } }, "localname": "LossContingencyPendingClaimsNumber", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "integerItemType" }, "us-gaap_MachineryAndEquipmentMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment.", "label": "Machinery And Equipment [Member]", "terseLabel": "Machinery and Equipment [Member]" } } }, "localname": "MachineryAndEquipmentMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail" ], "xbrltype": "domainItemType" }, "us-gaap_MaximumLengthOfTimeHedgedInCashFlowHedge1": { "auth_ref": [ "r376" ], "lang": { "en-US": { "role": { "documentation": "Maximum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.", "label": "Maximum Length Of Time Hedged In Cash Flow Hedge1", "terseLabel": "Maximum period hedged in cash flow hedge" } } }, "localname": "MaximumLengthOfTimeHedgedInCashFlowHedge1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsAdditionalInformationDetail" ], "xbrltype": "durationItemType" }, "us-gaap_MinorityInterest": { "auth_ref": [ "r63", "r415", "r432" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10050.0, "parentTag": "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest).", "label": "Minority Interest", "terseLabel": "Noncontrolling interests" } } }, "localname": "MinorityInterest", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_NetCashProvidedByUsedInDiscontinuedOperations": { "auth_ref": [ "r112" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Increase (decrease) in cash associated with the entity's discontinued operations.", "label": "Net Cash Provided By Used In Discontinued Operations", "terseLabel": "Net Cash Provided by (Used in) Discontinued Operations", "totalLabel": "Net (decrease) increase in cash and cash equivalents" } } }, "localname": "NetCashProvidedByUsedInDiscontinuedOperations", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsScheduleOfNetCashInflowsAndOutflowsFromDiscontinuedOperationsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_NetCashProvidedByUsedInFinancingActivities": { "auth_ref": [ "r112" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10030.0, "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.", "label": "Net Cash Provided By Used In Financing Activities", "totalLabel": "Net cash provided by financing activities" } } }, "localname": "NetCashProvidedByUsedInFinancingActivities", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Net Cash Provided By Used In Financing Activities [Abstract]", "terseLabel": "Cash provided by (used in) financing activities:" } } }, "localname": "NetCashProvidedByUsedInFinancingActivitiesAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_NetCashProvidedByUsedInInvestingActivities": { "auth_ref": [ "r112" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10020.0, "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.", "label": "Net Cash Provided By Used In Investing Activities", "totalLabel": "Net cash used in investing activities" } } }, "localname": "NetCashProvidedByUsedInInvestingActivities", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Net Cash Provided By Used In Investing Activities [Abstract]", "terseLabel": "Cash (used in) provided by investing activities:" } } }, "localname": "NetCashProvidedByUsedInInvestingActivitiesAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_NetCashProvidedByUsedInOperatingActivities": { "auth_ref": [ "r112", "r113", "r116" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10010.0, "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.", "label": "Net Cash Provided By Used In Operating Activities", "totalLabel": "Net cash used in operating activities" } } }, "localname": "NetCashProvidedByUsedInOperatingActivities", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Net Cash Provided By Used In Operating Activities [Abstract]", "terseLabel": "Cash (used in) provided by operating activities:" } } }, "localname": "NetCashProvidedByUsedInOperatingActivitiesAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_NetIncomeLoss": { "auth_ref": [ "r84", "r86", "r93", "r116", "r134", "r422", "r439" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail": { "order": null, "parentTag": null, "root": true, "weight": null }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.", "label": "Net Income Loss", "totalLabel": "Net (loss) income attributable to Koppers" } } }, "localname": "NetIncomeLoss", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_NetIncomeLossAttributableToNoncontrollingInterest": { "auth_ref": [ "r84", "r86", "r341", "r345" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10080.0, "parentTag": "us-gaap_NetIncomeLoss", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of Net Income (Loss) attributable to noncontrolling interest.", "label": "Net Income Loss Attributable To Noncontrolling Interest", "terseLabel": "Net (loss) income attributable to noncontrolling interests" } } }, "localname": "NetIncomeLossAttributableToNoncontrollingInterest", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock": { "auth_ref": [ "r125" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items.", "label": "New Accounting Pronouncements And Changes In Accounting Principles [Text Block]", "terseLabel": "New Accounting Pronouncements" } } }, "localname": "NewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureNewAccountingPronouncements" ], "xbrltype": "textBlockItemType" }, "us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Disclosure of accounting policy pertaining to new accounting pronouncements that may impact the entity's financial reporting. Includes, but is not limited to, quantification of the expected or actual impact.", "label": "New Accounting Pronouncements Policy Policy [Text Block]", "terseLabel": "New Accounting Pronouncements" } } }, "localname": "NewAccountingPronouncementsPolicyPolicyTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureNewAccountingPronouncementsPolicies" ], "xbrltype": "textBlockItemType" }, "us-gaap_NoncontrollingInterestMember": { "auth_ref": [ "r334" ], "lang": { "en-US": { "role": { "documentation": "This element represents that portion of equity (net assets) in a subsidiary not attributable, directly or indirectly, to the parent. A noncontrolling interest is sometimes called a minority interest.", "label": "Noncontrolling Interest [Member]", "terseLabel": "Noncontrolling Interests [Member]" } } }, "localname": "NoncontrollingInterestMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "domainItemType" }, "us-gaap_NondesignatedMember": { "auth_ref": [ "r357" ], "lang": { "en-US": { "role": { "documentation": "Derivative instrument not designated as hedging instrument under Generally Accepted Accounting Principles (GAAP).", "label": "Nondesignated [Member]", "terseLabel": "Not Designated as Hedging Instrument" } } }, "localname": "NondesignatedMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_NonoperatingIncomeExpense": { "auth_ref": [ "r99" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).", "label": "Nonoperating Income Expense", "terseLabel": "Other income, net" } } }, "localname": "NonoperatingIncomeExpense", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_NumberOfReportableSegments": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.", "label": "Number Of Reportable Segments", "terseLabel": "Number of reportable segments" } } }, "localname": "NumberOfReportableSegments", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail" ], "xbrltype": "integerItemType" }, "us-gaap_OffsettingAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Offsetting [Abstract]" } } }, "localname": "OffsettingAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_OperatingIncomeLoss": { "auth_ref": [], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": null, "parentTag": null, "root": true, "weight": null } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The net result for the period of deducting operating expenses from operating revenues.", "label": "Operating Income Loss", "totalLabel": "Operating profit", "verboseLabel": "Operating profit (loss)" } } }, "localname": "OperatingIncomeLoss", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_OperatingLeaseCost": { "auth_ref": [ "r400", "r407" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.", "label": "Operating Lease Cost", "terseLabel": "Operating lease costs" } } }, "localname": "OperatingLeaseCost", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OperatingLeaseLiability": { "auth_ref": [ "r398" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail": { "order": null, "parentTag": null, "root": true, "weight": null }, "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail2": { "order": 10020.0, "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease.", "label": "Operating Lease Liability", "terseLabel": "Present value of lease liabilities", "totalLabel": "Total operating lease liabilities" } } }, "localname": "OperatingLeaseLiability", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesSummaryOfAmountAndTimingOfCashFlowsFromOperatingLeasesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OperatingLeaseLiabilityCurrent": { "auth_ref": [ "r398" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail": { "order": 10010.0, "parentTag": "us-gaap_OperatingLeaseLiability", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10210.0, "parentTag": "us-gaap_LiabilitiesCurrent", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.", "label": "Operating Lease Liability Current", "terseLabel": "Current operating lease liabilities" } } }, "localname": "OperatingLeaseLiabilityCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_OperatingLeaseLiabilityNoncurrent": { "auth_ref": [ "r398" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail": { "order": 10020.0, "parentTag": "us-gaap_OperatingLeaseLiability", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10160.0, "parentTag": "us-gaap_Liabilities", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.", "label": "Operating Lease Liability Noncurrent", "terseLabel": "Operating lease liabilities" } } }, "localname": "OperatingLeaseLiabilityNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_OperatingLeasePayments": { "auth_ref": [ "r399", "r402" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.", "label": "Operating Lease Payments", "terseLabel": "Operating cash outflow from operating leases" } } }, "localname": "OperatingLeasePayments", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_OperatingLeaseRightOfUseAsset": { "auth_ref": [ "r397" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10260.0, "parentTag": "us-gaap_Assets", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of lessee's right to use underlying asset under operating lease.", "label": "Operating Lease Right Of Use Asset", "terseLabel": "Operating lease right-of-use assets" } } }, "localname": "OperatingLeaseRightOfUseAsset", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent": { "auth_ref": [ "r405", "r407" ], "lang": { "en-US": { "role": { "documentation": "Weighted average discount rate for operating lease calculated at point in time.", "label": "Operating Lease Weighted Average Discount Rate Percent", "terseLabel": "Weighted average discount rate" } } }, "localname": "OperatingLeaseWeightedAverageDiscountRatePercent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail" ], "xbrltype": "percentItemType" }, "us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1": { "auth_ref": [ "r404", "r407" ], "lang": { "en-US": { "role": { "documentation": "Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.", "label": "Operating Lease Weighted Average Remaining Lease Term1", "terseLabel": "Weighted average remaining lease term, in years" } } }, "localname": "OperatingLeaseWeightedAverageRemainingLeaseTerm1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesScheduleOfSupplementalConsolidatedBalanceSheetInformationRelatedToLeasesDetail" ], "xbrltype": "durationItemType" }, "us-gaap_OperatingSegmentsMember": { "auth_ref": [ "r144", "r153" ], "lang": { "en-US": { "role": { "documentation": "Identifies components of an entity that engage in business activities from which they may earn revenue and incur expenses, including transactions with other components of the same entity.", "label": "Operating Segments [Member]", "terseLabel": "Operating Segments [Member]" } } }, "localname": "OperatingSegmentsMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Organization Consolidation And Presentation Of Financial Statements [Abstract]" } } }, "localname": "OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock": { "auth_ref": [ "r18", "r348" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.", "label": "Organization Consolidation And Presentation Of Financial Statements Disclosure [Text Block]", "terseLabel": "Basis of Presentation" } } }, "localname": "OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureBasisOfPresentation" ], "xbrltype": "textBlockItemType" }, "us-gaap_OtherAssetsCurrent": { "auth_ref": [ "r69" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10370.0, "parentTag": "us-gaap_AssetsCurrent", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of current assets classified as other.", "label": "Other Assets Current", "terseLabel": "Other current assets" } } }, "localname": "OtherAssetsCurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherAssetsFairValueDisclosure": { "auth_ref": [], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Fair value portion of other assets.", "label": "Other Assets Fair Value Disclosure", "terseLabel": "Investments and other assets" } } }, "localname": "OtherAssetsFairValueDisclosure", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherAssetsMember": { "auth_ref": [ "r360", "r373" ], "lang": { "en-US": { "role": { "documentation": "Primary financial statement caption encompassing other assets.", "label": "Other Assets [Member]", "terseLabel": "Other Assets [Member]" } } }, "localname": "OtherAssetsMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail" ], "xbrltype": "domainItemType" }, "us-gaap_OtherAssetsNoncurrent": { "auth_ref": [ "r47" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10310.0, "parentTag": "us-gaap_Assets", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of noncurrent assets classified as other.", "label": "Other Assets Noncurrent", "terseLabel": "Other assets" } } }, "localname": "OtherAssetsNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax": { "auth_ref": [ "r75", "r77", "r266" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail": { "order": 10040.0, "parentTag": "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount, after tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.", "label": "Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax", "terseLabel": "Unrecognized pension net loss", "verboseLabel": "Unrecognized pension net loss, net of tax (expense) of $(0.1)" } } }, "localname": "OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax": { "auth_ref": [ "r78" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of tax expense (benefit) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.", "label": "Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax", "terseLabel": "Tax expense, unrecognized pension net loss" } } }, "localname": "OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeParentheticalDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax": { "auth_ref": [ "r73", "r388" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail": { "order": 10020.0, "parentTag": "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.", "label": "Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax", "terseLabel": "Currency translation adjustment" } } }, "localname": "OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Other Comprehensive Income Loss Net Of Tax Period Increase Decrease [Abstract]", "terseLabel": "Other comprehensive (loss) income", "verboseLabel": "Changes in other comprehensive (loss) income:" } } }, "localname": "OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail" ], "xbrltype": "stringItemType" }, "us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax": { "auth_ref": [ "r77", "r81", "r82", "r358" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).", "label": "Other Comprehensive Income Loss Reclassification Adjustment From A O C I On Derivatives Net Of Tax", "negatedLabel": "Income (loss) related to derivative instrument" } } }, "localname": "OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax": { "auth_ref": [ "r74", "r77", "r375" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).", "label": "Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax", "terseLabel": "Accumulated other comprehensive (loss) gain, net of tax" } } }, "localname": "OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax": { "auth_ref": [ "r74", "r77", "r375" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail": { "order": 10030.0, "parentTag": "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount after tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).", "label": "Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax", "terseLabel": "Unrealized loss on cash flow hedges", "verboseLabel": "Unrealized (loss) gain on cash flow hedges, net of tax benefit (expense) of $11.3 and $(2.8)" } } }, "localname": "OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax": { "auth_ref": [ "r74", "r78" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of tax expense (benefit), before reclassification adjustments, related to increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).", "label": "Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax", "negatedLabel": "Tax benefit (expense), unrealized (loss) gain on cash flow hedges" } } }, "localname": "OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeParentheticalDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherCurrentAssetsMember": { "auth_ref": [ "r360", "r373" ], "lang": { "en-US": { "role": { "documentation": "Primary financial statement caption encompassing other current assets.", "label": "Other Current Assets [Member]", "terseLabel": "Other Current Assets [Member]" } } }, "localname": "OtherCurrentAssetsMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_OtherLiabilitiesNoncurrent": { "auth_ref": [ "r58" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10180.0, "parentTag": "us-gaap_Liabilities", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.", "label": "Other Liabilities Noncurrent", "terseLabel": "Other long-term liabilities" } } }, "localname": "OtherLiabilitiesNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherNoncashIncomeExpense": { "auth_ref": [ "r116" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10220.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of income (expense) included in net income that results in no cash inflow (outflow), classified as other.", "label": "Other Noncash Income Expense", "negatedLabel": "Other - net" } } }, "localname": "OtherNoncashIncomeExpense", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_OtherNoncurrentLiabilitiesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Primary financial statement caption encompassing other noncurrent liabilities.", "label": "Other Noncurrent Liabilities [Member]", "terseLabel": "Other Long-term Liabilities [Member]" } } }, "localname": "OtherNoncurrentLiabilitiesMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail" ], "xbrltype": "domainItemType" }, "us-gaap_OtherRestructuringMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Restructuring and related activities classified as other.", "label": "Other Restructuring [Member]", "terseLabel": "Other [Member]" } } }, "localname": "OtherRestructuringMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "domainItemType" }, "us-gaap_PaymentsForRepurchaseOfCommonStock": { "auth_ref": [ "r106" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10090.0, "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The cash outflow to reacquire common stock during the period.", "label": "Payments For Repurchase Of Common Stock", "negatedLabel": "Repurchases of Common Stock" } } }, "localname": "PaymentsForRepurchaseOfCommonStock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_PaymentsForRestructuring": { "auth_ref": [ "r110", "r209" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.", "label": "Payments For Restructuring", "negatedLabel": "Cash paid" } } }, "localname": "PaymentsForRestructuring", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_PaymentsOfDebtIssuanceCosts": { "auth_ref": [ "r108" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10100.0, "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.", "label": "Payments Of Debt Issuance Costs", "negatedLabel": "Payment of debt issuance costs" } } }, "localname": "PaymentsOfDebtIssuanceCosts", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_PaymentsToAcquirePropertyPlantAndEquipment": { "auth_ref": [ "r104" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10110.0, "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.", "label": "Payments To Acquire Property Plant And Equipment", "negatedLabel": "Capital expenditures" } } }, "localname": "PaymentsToAcquirePropertyPlantAndEquipment", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock": { "auth_ref": [ "r278" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for pension and other postretirement benefits.", "label": "Pension And Other Postretirement Benefits Disclosure [Text Block]", "terseLabel": "Pensions and Post-Retirement Benefit Plans" } } }, "localname": "PensionAndOtherPostretirementBenefitsDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlans" ], "xbrltype": "textBlockItemType" }, "us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent": { "auth_ref": [ "r31", "r256", "r257", "r260" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10140.0, "parentTag": "us-gaap_Liabilities", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent.", "label": "Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent", "terseLabel": "Accrued postretirement benefits" } } }, "localname": "PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_PerformanceSharesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Share-based payment arrangement awarded for meeting performance target.", "label": "Performance Shares [Member]", "terseLabel": "Performance Stock Units [Member]" } } }, "localname": "PerformanceSharesMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "domainItemType" }, "us-gaap_PortionAtFairValueFairValueDisclosureMember": { "auth_ref": [ "r383" ], "lang": { "en-US": { "role": { "documentation": "Measured at fair value for financial reporting purposes.", "label": "Portion At Fair Value Fair Value Disclosure [Member]", "terseLabel": "Fair Value Disclosure Item Amounts [Default]" } } }, "localname": "PortionAtFairValueFairValueDisclosureMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfCompanySFinancialInstrumentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_PostemploymentBenefitsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Postemployment Benefits [Abstract]" } } }, "localname": "PostemploymentBenefitsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_PreferredStockParOrStatedValuePerShare": { "auth_ref": [ "r32" ], "lang": { "en-US": { "role": { "documentation": "Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.", "label": "Preferred Stock Par Or Stated Value Per Share", "terseLabel": "Senior Convertible Preferred Stock, par value" } } }, "localname": "PreferredStockParOrStatedValuePerShare", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetParenthetical" ], "xbrltype": "perShareItemType" }, "us-gaap_PreferredStockSharesAuthorized": { "auth_ref": [ "r32" ], "lang": { "en-US": { "role": { "documentation": "The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.", "label": "Preferred Stock Shares Authorized", "terseLabel": "Senior Convertible Preferred Stock, shares authorized" } } }, "localname": "PreferredStockSharesAuthorized", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetParenthetical" ], "xbrltype": "sharesItemType" }, "us-gaap_PreferredStockSharesIssued": { "auth_ref": [ "r32" ], "lang": { "en-US": { "role": { "documentation": "Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.", "label": "Preferred Stock Shares Issued", "terseLabel": "Senior Convertible Preferred Stock, shares issued" } } }, "localname": "PreferredStockSharesIssued", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetParenthetical" ], "xbrltype": "sharesItemType" }, "us-gaap_PreferredStockValue": { "auth_ref": [ "r32" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10060.0, "parentTag": "us-gaap_StockholdersEquity", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Aggregate par or stated value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity.", "label": "Preferred Stock Value", "terseLabel": "Senior Convertible Preferred Stock, $0.01 par value per share; 10,000,000 shares authorized; no shares issued" } } }, "localname": "PreferredStockValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_ProceedsFromIssuanceOfCommonStock": { "auth_ref": [ "r105" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10080.0, "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The cash inflow from the additional capital contribution to the entity.", "label": "Proceeds From Issuance Of Common Stock", "terseLabel": "Issuances of Common Stock" } } }, "localname": "ProceedsFromIssuanceOfCommonStock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_ProceedsFromRepaymentsOfLinesOfCredit": { "auth_ref": [ "r123" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10060.0, "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The net cash inflow or cash outflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with either short term or long term maturity that is collateralized (backed by pledge, mortgage or other lien in the entity's assets).", "label": "Proceeds From Repayments Of Lines Of Credit", "terseLabel": "Net increase in credit facility borrowings" } } }, "localname": "ProceedsFromRepaymentsOfLinesOfCredit", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_ProceedsFromSaleOfInsuranceInvestments": { "auth_ref": [ "r103" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10120.0, "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The cash inflow associated with the sale of insurance policy investment assets during the period.", "label": "Proceeds From Sale Of Insurance Investments", "terseLabel": "Insurance proceeds received" } } }, "localname": "ProceedsFromSaleOfInsuranceInvestments", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_ProfitLoss": { "auth_ref": [ "r84", "r86", "r111", "r147", "r154", "r337", "r340", "r342", "r345", "r346" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail": { "order": 10010.0, "parentTag": "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10140.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": 1.0 }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10070.0, "parentTag": "us-gaap_NetIncomeLoss", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.", "label": "Profit Loss", "terseLabel": "Net (loss) income", "totalLabel": "Net (loss) income", "verboseLabel": "Net loss" } } }, "localname": "ProfitLoss", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfComprehensiveIncomeDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_PropertyPlantAndEquipmentAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Property Plant And Equipment [Abstract]" } } }, "localname": "PropertyPlantAndEquipmentAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_PropertyPlantAndEquipmentByTypeAxis": { "auth_ref": [ "r46", "r189" ], "lang": { "en-US": { "role": { "documentation": "Information by type of long-lived, physical assets used to produce goods and services and not intended for resale.", "label": "Property Plant And Equipment By Type [Axis]", "terseLabel": "Property, Plant and Equipment, Type" } } }, "localname": "PropertyPlantAndEquipmentByTypeAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail" ], "xbrltype": "stringItemType" }, "us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock": { "auth_ref": [ "r193" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for long-lived, physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, accounting policies and methodology, roll forwards, depreciation, depletion and amortization expense, including composite depreciation, accumulated depreciation, depletion and amortization expense, useful lives and method used, income statement disclosures, assets held for sale and public utility disclosures.", "label": "Property Plant And Equipment Disclosure [Text Block]", "terseLabel": "Property, Plant and Equipment" } } }, "localname": "PropertyPlantAndEquipmentDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipment" ], "xbrltype": "textBlockItemType" }, "us-gaap_PropertyPlantAndEquipmentGross": { "auth_ref": [ "r45", "r187" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail": { "order": 10010.0, "parentTag": "us-gaap_PropertyPlantAndEquipmentNet", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.", "label": "Property Plant And Equipment Gross", "terseLabel": "Property, plant and equipment, gross" } } }, "localname": "PropertyPlantAndEquipmentGross", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_PropertyPlantAndEquipmentLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Property Plant And Equipment [Line Items]", "terseLabel": "Property, Plant and Equipment [Line Items]" } } }, "localname": "PropertyPlantAndEquipmentLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentParentheticalDetail" ], "xbrltype": "stringItemType" }, "us-gaap_PropertyPlantAndEquipmentNet": { "auth_ref": [ "r26", "r27", "r189", "r434" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail": { "order": null, "parentTag": null, "root": true, "weight": null }, "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10250.0, "parentTag": "us-gaap_Assets", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.", "label": "Property Plant And Equipment Net", "terseLabel": "Property, plant and equipment, net", "totalLabel": "Net" } } }, "localname": "PropertyPlantAndEquipmentNet", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_PropertyPlantAndEquipmentTextBlock": { "auth_ref": [ "r26", "r189" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, balances by class of assets, depreciation and depletion expense and method used, including composite depreciation, and accumulated deprecation.", "label": "Property Plant And Equipment [Text Block]", "terseLabel": "Property, Plant and Equipment" } } }, "localname": "PropertyPlantAndEquipmentTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_PropertyPlantAndEquipmentTypeDomain": { "auth_ref": [ "r26", "r187" ], "lang": { "en-US": { "role": { "documentation": "Listing of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.", "label": "Property Plant And Equipment Type [Domain]", "terseLabel": "Property, Plant and Equipment, Type" } } }, "localname": "PropertyPlantAndEquipmentTypeDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail" ], "xbrltype": "domainItemType" }, "us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTable": { "auth_ref": [ "r150", "r152" ], "lang": { "en-US": { "role": { "documentation": "Identification, description, and amounts of all significant reconciling items in the reconciliation of total assets from reportable segments to the entity's consolidated assets.", "label": "Reconciliation Of Assets From Segment To Consolidated [Table]", "terseLabel": "Reconciliation Of Assets From Segment To Consolidated [Table]" } } }, "localname": "ReconciliationOfAssetsFromSegmentToConsolidatedTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock": { "auth_ref": [ "r150", "r152" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of all significant reconciling items in the reconciliation of total assets from reportable segments to the entity's consolidated assets.", "label": "Reconciliation Of Assets From Segment To Consolidated [Text Block]", "terseLabel": "Summary of Tangible and Intangible Assets by Segments" } } }, "localname": "ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTextBlock": { "auth_ref": [ "r149", "r152" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of all significant reconciling items in the reconciliation of total revenues from reportable segments to the entity's consolidated revenues.", "label": "Reconciliation Of Revenue From Segments To Consolidated [Text Block]", "terseLabel": "Summary of Results of Segment Operations" } } }, "localname": "ReconciliationOfRevenueFromSegmentsToConsolidatedTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_RepaymentsOfLongTermDebt": { "auth_ref": [ "r107" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10070.0, "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.", "label": "Repayments Of Long Term Debt", "negatedLabel": "Repayments of long-term debt" } } }, "localname": "RepaymentsOfLongTermDebt", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_RestrictedStockUnitsRSUMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Share instrument which is convertible to stock or an equivalent amount of cash, after a specified period of time or when specified performance conditions are met.", "label": "Restricted Stock Units R S U [Member]", "terseLabel": "Restricted Stock Units (RSUs) [Member]" } } }, "localname": "RestrictedStockUnitsRSUMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_RestructuringCostAndReserveAxis": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Information by type of restructuring cost.", "label": "Restructuring Cost And Reserve [Axis]", "terseLabel": "Asset Retirement [Member]" } } }, "localname": "RestructuringCostAndReserveAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "stringItemType" }, "us-gaap_RestructuringCostAndReserveLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Restructuring Cost And Reserve [Line Items]", "terseLabel": "Restructuring Cost and Reserve [Line Items]" } } }, "localname": "RestructuringCostAndReserveLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "stringItemType" }, "us-gaap_RestructuringCostsAndAssetImpairmentCharges": { "auth_ref": [ "r115" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10170.0, "parentTag": "us-gaap_OperatingIncomeLoss", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount, after cash payment, of expenses associated with exit or disposal activities pursuant to an authorized plan and expenses resulting from the write-down of assets. Excludes expenses related to a business combination, a discontinued operation or an asset retirement obligation.", "label": "Restructuring Costs And Asset Impairment Charges", "terseLabel": "Impairment and restructuring charges" } } }, "localname": "RestructuringCostsAndAssetImpairmentCharges", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_RestructuringReserve": { "auth_ref": [ "r209", "r214" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.", "label": "Restructuring Reserve", "periodEndLabel": "Reserve, Ending Balance", "periodStartLabel": "Reserve, Beginning Balance" } } }, "localname": "RestructuringReserve", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_RestructuringReserveAccrualAdjustment1": { "auth_ref": [ "r208", "r213" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of expense (reversal of expense) which increases (decreases) the restructuring reserve from an adjustment to a previously accrued restructuring liability.", "label": "Restructuring Reserve Accrual Adjustment1", "negatedLabel": "Reversal of accrued charges" } } }, "localname": "RestructuringReserveAccrualAdjustment1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_RestructuringReserveTranslationAdjustment": { "auth_ref": [ "r209", "r216" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of foreign currency translation gain (loss) which decreases (increases) the restructuring reserve.", "label": "Restructuring Reserve Translation Adjustment", "terseLabel": "Currency translation" } } }, "localname": "RestructuringReserveTranslationAdjustment", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_RetainedEarningsAccumulatedDeficit": { "auth_ref": [ "r36", "r245", "r431" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10090.0, "parentTag": "us-gaap_StockholdersEquity", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.", "label": "Retained Earnings Accumulated Deficit", "terseLabel": "Retained earnings" } } }, "localname": "RetainedEarningsAccumulatedDeficit", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_RetainedEarningsMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.", "label": "Retained Earnings [Member]", "terseLabel": "Retained Earnings [Member]" } } }, "localname": "RetainedEarningsMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "domainItemType" }, "us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax": { "auth_ref": [ "r251", "r252" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10140.0, "parentTag": "us-gaap_OperatingIncomeLoss", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.", "label": "Revenue From Contract With Customer Excluding Assessed Tax", "terseLabel": "Net sales" } } }, "localname": "RevenueFromContractWithCustomerExcludingAssessedTax", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_RevolvingCreditFacilityMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Arrangement in which loan proceeds can continuously be obtained following repayments, but the total amount borrowed cannot exceed a specified maximum amount.", "label": "Revolving Credit Facility [Member]", "terseLabel": "Revolving Credit Facility [Member]" } } }, "localname": "RevolvingCreditFacilityMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability": { "auth_ref": [ "r403", "r407" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of increase in right-of-use asset obtained in exchange for operating lease liability.", "label": "Right Of Use Asset Obtained In Exchange For Operating Lease Liability", "terseLabel": "Right-of-use assets obtained in exchange for new operating lease liabilities" } } }, "localname": "RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the components of accrued liabilities.", "label": "Schedule Of Accrued Liabilities Table [Text Block]", "terseLabel": "Changes in Accrued Liability for Environmental Matters" } } }, "localname": "ScheduleOfAccruedLiabilitiesTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfChangeInAssetRetirementObligationTableTextBlock": { "auth_ref": [ "r206" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation.", "label": "Schedule Of Change In Asset Retirement Obligation Table [Text Block]", "terseLabel": "Schedule of Changes in Carrying Values of Asset Retirement Obligations" } } }, "localname": "ScheduleOfChangeInAssetRetirementObligationTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureAssetRetirementObligationsTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock": { "auth_ref": [ "r307" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of cost recognized for award under share-based payment arrangement by plan. Includes, but is not limited to, related tax benefit.", "label": "Schedule Of Compensation Cost For Share Based Payment Arrangements Allocation Of Share Based Compensation Costs By Plan Table [Text Block]", "terseLabel": "Schedule of Stock-based Compensation Expense Recognized" } } }, "localname": "ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock": { "auth_ref": [ "r72" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of components of comprehensive income (loss). Includes, but is not limited to, foreign currency translation adjustments, foreign currency transactions designated as economic hedges of a net investment in foreign entity, gain (loss) and prior service cost (credit) for pension plans and other postretirement benefit plans.", "label": "Schedule Of Comprehensive Income Loss Table [Text Block]", "terseLabel": "Schedule of Comprehensive Income" } } }, "localname": "ScheduleOfComprehensiveIncomeLossTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfDebtInstrumentsTextBlock": { "auth_ref": [ "r57", "r120", "r241", "r242", "r243", "r244", "r391", "r392", "r394", "r427" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.", "label": "Schedule Of Debt Instruments [Text Block]", "terseLabel": "Schedule of Long-Term Debt Instruments" } } }, "localname": "ScheduleOfDebtInstrumentsTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable": { "auth_ref": [ "r267", "r268", "r269", "r270", "r276" ], "lang": { "en-US": { "role": { "documentation": "Disclosures about an individual defined benefit pension plan or an other postretirement defined benefit plan. It may be appropriate to group certain similar plans. Also includes schedule for fair value of plan assets by major categories of plan assets by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets or liabilities (Level 1), Significant other observable inputs (Level 2), and significant unobservable inputs (Level 3).", "label": "Schedule Of Defined Benefit Plans Disclosures [Table]", "terseLabel": "Schedule Of Defined Benefit Plans Disclosures [Table]" } } }, "localname": "ScheduleOfDefinedBenefitPlansDisclosuresTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock": { "auth_ref": [ "r361", "r367", "r370" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the location and amount of derivative instruments and nonderivative instruments designated as hedging instruments reported before netting adjustments, and the amount of gain (loss) on derivative instruments and nonderivative instruments designated and qualified as hedging instruments.", "label": "Schedule Of Derivative Instruments Gain Loss In Statement Of Financial Performance [Text Block]", "terseLabel": "Schedule of (Loss) Gain from Contract Not Designated as Hedges" } } }, "localname": "ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock": { "auth_ref": [ "r364" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position.", "label": "Schedule Of Derivative Instruments In Statement Of Financial Position Fair Value [Text Block]", "terseLabel": "Schedule of Fair Value of Outstanding Foreign Currency Forward Contracts" } } }, "localname": "ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfDifferencesBetweenReportedAmountAndReportingCurrencyDenominatedAmountTableTextBlock": { "auth_ref": [ "r389" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the U.S. dollar denominated balances, balances reported for financial reporting purposes and the differences between the two balances by each relevant line item on the financial statements.", "label": "Schedule Of Differences Between Reported Amount And Reporting Currency Denominated Amount Table [Text Block]", "terseLabel": "Summary of Net Currency Units Outstanding" } } }, "localname": "ScheduleOfDifferencesBetweenReportedAmountAndReportingCurrencyDenominatedAmountTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock": { "auth_ref": [ "r134" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations.", "label": "Schedule Of Earnings Per Share Basic And Diluted Table [Text Block]", "terseLabel": "Schedule of Computation of Basic and Diluted Earnings per Common Share" } } }, "localname": "ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock": { "auth_ref": [ "r321" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations.", "label": "Schedule Of Effective Income Tax Rate Reconciliation Table [Text Block]", "terseLabel": "Summary of Income Taxes Reconciled with Federal Statutory Rate" } } }, "localname": "ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable": { "auth_ref": [ "r280", "r307", "r312" ], "lang": { "en-US": { "role": { "documentation": "Disclosure of information about amount recognized for award under share-based payment arrangement. Includes, but is not limited to, amount expensed in statement of income or comprehensive income, amount capitalized in statement of financial position, and corresponding reporting line item in financial statements.", "label": "Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table]", "terseLabel": "Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table]" } } }, "localname": "ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable": { "auth_ref": [ "r156" ], "lang": { "en-US": { "role": { "documentation": "Tabular presentation of the description and amount of revenues from a product or service, or a group of similar products or similar services, reported from external customers during the period, if the information is not provided as part of the reportable operating segment information.", "label": "Schedule Of Entity Wide Information Revenue From External Customers By Products And Services [Table]", "terseLabel": "Schedule Of Entity Wide Information Revenue From External Customers By Products And Services [Table]" } } }, "localname": "ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTextBlock": { "auth_ref": [ "r156" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of entity-wide revenues from external customers for each product or service or each group of similar products or services if the information is not provided as part of the reportable operating segment information.", "label": "Schedule Of Entity Wide Information Revenue From External Customers By Products And Services [Text Block]", "terseLabel": "Schedule of Segment Revenues for Significant Product Lines" } } }, "localname": "ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfEquityMethodInvestmentsLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Schedule Of Equity Method Investments [Line Items]", "terseLabel": "Schedule Of Equity Method Investments [Line Items]" } } }, "localname": "ScheduleOfEquityMethodInvestmentsLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ScheduleOfEquityMethodInvestmentsTable": { "auth_ref": [ "r165" ], "lang": { "en-US": { "role": { "documentation": "Summarization of information required and determined to be disclosed concerning equity method investments in common stock. The summarized information includes: (a) the name of each investee or group of investees for which combined disclosure is appropriate, (2) the percentage ownership of common stock, (3) the difference, if any, between the carrying amount of an investment and the value of the underlying equity in the net assets and the accounting treatment of difference, if any, and (4) the aggregate value of each identified investment based on its quoted market price, if available.", "label": "Schedule Of Equity Method Investments [Table]", "terseLabel": "Schedule Of Equity Method Investments [Table]" } } }, "localname": "ScheduleOfEquityMethodInvestmentsTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock": { "auth_ref": [ "r365" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure for fair value hedging instruments of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position.", "label": "Schedule Of Fair Value Hedging Instruments Statements Of Financial Performance And Financial Position Location Table [Text Block]", "terseLabel": "Schedule of Fair Value of Outstanding Copper Swap Contracts Recorded in Balance Sheet" } } }, "localname": "ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock": { "auth_ref": [ "r395" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of future minimum payments required in the aggregate and for each of the five succeeding fiscal years for operating leases having initial or remaining noncancelable lease terms in excess of one year and the total minimum rentals to be received in the future under noncancelable subleases as of the balance sheet date.", "label": "Schedule Of Future Minimum Rental Payments For Operating Leases Table [Text Block]", "terseLabel": "Summary of Amount and Timing of Cash Flows From Operating Leases" } } }, "localname": "ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfInventoryCurrentTableTextBlock": { "auth_ref": [ "r25", "r41", "r42", "r43" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.", "label": "Schedule Of Inventory Current Table [Text Block]", "terseLabel": "Components of Net Inventories" } } }, "localname": "ScheduleOfInventoryCurrentTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureInventoriesTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfNetBenefitCostsTableTextBlock": { "auth_ref": [ "r261" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments.", "label": "Schedule Of Net Benefit Costs Table [Text Block]", "terseLabel": "Components of Net Periodic Benefit Cost for Pension Plans" } } }, "localname": "ScheduleOfNetBenefitCostsTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePensionsAndPostRetirementBenefitPlansTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock": { "auth_ref": [ "r292" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the changes in outstanding nonvested performance-based units.", "label": "Schedule Of Nonvested Performance Based Units Activity Table [Text Block]", "terseLabel": "Summary of Performance Stock Units" } } }, "localname": "ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock": { "auth_ref": [ "r292" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the changes in outstanding nonvested shares.", "label": "Schedule Of Nonvested Share Activity Table [Text Block]", "terseLabel": "Summary of Status and Activity of Non-Vested Stock Awards" } } }, "localname": "ScheduleOfNonvestedShareActivityTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock": { "auth_ref": [ "r353" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the notional amounts of outstanding derivative positions.", "label": "Schedule Of Notional Amounts Of Outstanding Derivative Positions Table [Text Block]", "terseLabel": "Schedule of Outstanding Copper Swap Contracts" } } }, "localname": "ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfPropertyPlantAndEquipmentTable": { "auth_ref": [ "r46", "r189" ], "lang": { "en-US": { "role": { "documentation": "Disclosure of information about physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, balances by class of assets, depreciation and depletion expense and method used, including composite depreciation, and accumulated deprecation.", "label": "Schedule Of Property Plant And Equipment [Table]", "terseLabel": "Schedule Of Property Plant And Equipment [Table]" } } }, "localname": "ScheduleOfPropertyPlantAndEquipmentTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipmentParentheticalDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ScheduleOfRestructuringAndRelatedCostsTable": { "auth_ref": [ "r211", "r212", "r215" ], "lang": { "en-US": { "role": { "documentation": "Table presenting the description of the restructuring costs, such as the expected cost; the costs incurred during the period; the cumulative costs incurred as of the balance sheet date; the income statement caption within which the restructuring charges recognized for the period are included; and the amount of and periodic changes to an entity's restructuring reserve that occurred during the period associated with the exit from or disposal of business activities or restructurings for each major type of cost by type of restructuring.", "label": "Schedule Of Restructuring And Related Costs [Table]", "terseLabel": "Schedule Of Restructuring And Related Costs [Table]" } } }, "localname": "ScheduleOfRestructuringAndRelatedCostsTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ScheduleOfRestructuringReserveByTypeOfCostTextBlock": { "auth_ref": [ "r209", "r216" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of an entity's restructuring reserve that occurred during the period associated with the exit from or disposal of business activities or restructurings for each major type of cost. This element may also include a description of any reversal and other adjustment made during the period to the amount of an accrued liability for restructuring activities. This element may be used to encapsulate the roll forward presentations of an entity's restructuring reserve by type of cost and in total, and explanation of changes that occurred in the period.", "label": "Schedule Of Restructuring Reserve By Type Of Cost [Text Block]", "terseLabel": "Summary of Restructuring Activities and Related Reserves" } } }, "localname": "ScheduleOfRestructuringReserveByTypeOfCostTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable": { "auth_ref": [ "r143", "r147", "r148", "r151", "r181" ], "lang": { "en-US": { "role": { "documentation": "A table disclosing the profit or loss and total assets for each reportable segment of the entity. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.", "label": "Schedule Of Segment Reporting Information By Segment [Table]", "terseLabel": "Schedule Of Segment Reporting Information By Segment [Table]" } } }, "localname": "ScheduleOfSegmentReportingInformationBySegmentTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable": { "auth_ref": [ "r282", "r310" ], "lang": { "en-US": { "role": { "documentation": "Disclosure of information about share-based payment arrangement.", "label": "Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table]", "terseLabel": "Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table]" } } }, "localname": "ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "stringItemType" }, "us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock": { "auth_ref": [ "r286", "r297", "r299" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value.", "label": "Schedule Of Share Based Compensation Stock Options Activity Table [Text Block]", "terseLabel": "Summary of Status and Activity of Stock Options" } } }, "localname": "ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock": { "auth_ref": [ "r301" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions.", "label": "Schedule Of Share Based Payment Award Stock Options Valuation Assumptions Table [Text Block]", "terseLabel": "Stock Options And Performance Award Fair Value Assumptions" } } }, "localname": "ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_ScheduleOfStockholdersEquityTableTextBlock": { "auth_ref": [ "r240" ], "lang": { "en-US": { "role": { "documentation": "Tabular disclosure of changes in the separate accounts comprising stockholders' equity (in addition to retained earnings) and of the changes in the number of shares of equity securities during at least the most recent annual fiscal period and any subsequent interim period presented is required to make the financial statements sufficiently informative if both financial position and results of operations are presented.", "label": "Schedule Of Stockholders Equity Table [Text Block]", "terseLabel": "Schedule of Change in Equity" } } }, "localname": "ScheduleOfStockholdersEquityTableTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityTables" ], "xbrltype": "textBlockItemType" }, "us-gaap_SecuredDebtMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Collateralized debt obligation backed by, for example, but not limited to, pledge, mortgage or other lien on the entity's assets.", "label": "Secured Debt [Member]", "terseLabel": "Secured Term Loan Facility [Member]" } } }, "localname": "SecuredDebtMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "domainItemType" }, "us-gaap_SecuredLongTermDebt": { "auth_ref": [ "r57" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets.", "label": "Secured Long Term Debt", "terseLabel": "Secured term loan" } } }, "localname": "SecuredLongTermDebt", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_SegmentDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Components of an entity that engage in business activities from which they may earn revenue and incur expenses, including transactions with other components of the same entity.", "label": "Segment [Domain]", "terseLabel": "Segments" } } }, "localname": "SegmentDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail" ], "xbrltype": "domainItemType" }, "us-gaap_SegmentReportingAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Segment Reporting [Abstract]" } } }, "localname": "SegmentReportingAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_SegmentReportingAssetReconcilingItemLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Segment Reporting Asset Reconciling Item [Line Items]", "terseLabel": "Segment Reporting Asset Reconciling Item [Line Items]" } } }, "localname": "SegmentReportingAssetReconcilingItemLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail" ], "xbrltype": "stringItemType" }, "us-gaap_SegmentReportingDisclosureTextBlock": { "auth_ref": [ "r158" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.", "label": "Segment Reporting Disclosure [Text Block]", "terseLabel": "Segment Information" } } }, "localname": "SegmentReportingDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformation" ], "xbrltype": "textBlockItemType" }, "us-gaap_SegmentReportingInformationLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Segment Reporting Information [Line Items]", "terseLabel": "Segment Reporting Information [Line Items]" } } }, "localname": "SegmentReportingInformationLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail" ], "xbrltype": "stringItemType" }, "us-gaap_SellingGeneralAndAdministrativeExpense": { "auth_ref": [ "r98", "r176" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited": { "order": 10180.0, "parentTag": "us-gaap_OperatingIncomeLoss", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.", "label": "Selling General And Administrative Expense", "terseLabel": "Selling, general and administrative expenses" } } }, "localname": "SellingGeneralAndAdministrativeExpense", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_SellingGeneralAndAdministrativeExpensesMember": { "auth_ref": [ "r101" ], "lang": { "en-US": { "role": { "documentation": "Primary financial statement caption encompassing selling, general and administrative expense.", "label": "Selling General And Administrative Expenses [Member]", "terseLabel": "Selling, General and Administrative Expenses [Member]" } } }, "localname": "SellingGeneralAndAdministrativeExpensesMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail" ], "xbrltype": "domainItemType" }, "us-gaap_SeniorNotesMember": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Bond that takes priority over other debt securities sold by the issuer. In the event the issuer goes bankrupt, senior debt holders receive priority for (must receive) repayment prior to (relative to) junior and unsecured (general) creditors.", "label": "Senior Notes [Member]", "terseLabel": "Senior Notes [Member]" } } }, "localname": "SeniorNotesMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDebtScheduleOfLongTermDebtInstrumentsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_ShareBasedCompensation": { "auth_ref": [ "r114" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10170.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": 1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of noncash expense for share-based payment arrangement.", "label": "Share Based Compensation", "terseLabel": "Stock-based compensation" } } }, "localname": "ShareBasedCompensation", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_ShareBasedCompensationAllocationAndClassificationInFinancialStatementsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Share Based Compensation Allocation And Classification In Financial Statements [Abstract]", "terseLabel": "Stock-based compensation expense recognized:" } } }, "localname": "ShareBasedCompensationAllocationAndClassificationInFinancialStatementsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseRecognizedDetail" ], "xbrltype": "stringItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1": { "auth_ref": [ "r283" ], "lang": { "en-US": { "role": { "documentation": "Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1", "terseLabel": "Stock-based awards, vesting period" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "durationItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod": { "auth_ref": [ "r290" ], "lang": { "en-US": { "role": { "documentation": "The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period", "negatedLabel": "Forfeited" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue": { "auth_ref": [ "r296" ], "lang": { "en-US": { "role": { "documentation": "Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value", "terseLabel": "Forfeited, Weighted Average Grant Date Fair Value per Unit" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod": { "auth_ref": [ "r294" ], "lang": { "en-US": { "role": { "documentation": "The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).", "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period", "terseLabel": "Granted" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue": { "auth_ref": [ "r294" ], "lang": { "en-US": { "role": { "documentation": "The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).", "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value", "terseLabel": "Granted, Weighted Average Grant Date Fair Value per Unit" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber": { "auth_ref": [ "r293" ], "lang": { "en-US": { "role": { "documentation": "The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number", "periodEndLabel": "Non-vested, Ending Balance", "periodStartLabel": "Non-vested, Beginning Balance", "terseLabel": "Number of shares outstanding" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue": { "auth_ref": [ "r293" ], "lang": { "en-US": { "role": { "documentation": "Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value", "periodEndLabel": "Ending Balance, Non-vested, Weighted Average Grant Date Fair Value per Unit", "periodStartLabel": "Beginning Balance, Non-vested, Weighted Average Grant Date Fair Value per Unit" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod": { "auth_ref": [ "r295" ], "lang": { "en-US": { "role": { "documentation": "The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period", "negatedLabel": "Vested" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue": { "auth_ref": [ "r295" ], "lang": { "en-US": { "role": { "documentation": "The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value", "terseLabel": "Vested, Weighted Average Grant Date Fair Value per Unit" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Agreed-upon price for the exchange of the underlying asset relating to the share-based payment award.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Exercise Price", "terseLabel": "Grant date price per share of performance award", "verboseLabel": "Grant date price per share of stock option award" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate": { "auth_ref": [ "r304" ], "lang": { "en-US": { "role": { "documentation": "The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate", "terseLabel": "Expected dividend yield per share" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "percentItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate": { "auth_ref": [ "r303" ], "lang": { "en-US": { "role": { "documentation": "The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate", "terseLabel": "Expected volatility" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "percentItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate": { "auth_ref": [ "r305" ], "lang": { "en-US": { "role": { "documentation": "The risk-free interest rate assumption that is used in valuing an option on its own shares.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate", "terseLabel": "Risk-free interest rate" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "percentItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.", "label": "Share Based Compensation Arrangement By Share Based Payment Award [Line Items]", "terseLabel": "Share-based Compensation Arrangement by Share-based Payment Award [Line Items]" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "stringItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber": { "auth_ref": [ "r289" ], "lang": { "en-US": { "role": { "documentation": "The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number", "periodEndLabel": "Options, Exercisable at March 31, 2020" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice": { "auth_ref": [ "r289" ], "lang": { "en-US": { "role": { "documentation": "The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price", "periodEndLabel": "Weighted Average Exercise Price per Option, Outstanding at March 31, 2020" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod": { "auth_ref": [ "r291" ], "lang": { "en-US": { "role": { "documentation": "Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period", "negatedLabel": "Options, Expired" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod": { "auth_ref": [ "r290" ], "lang": { "en-US": { "role": { "documentation": "The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period", "negatedLabel": "Options, Forfeited" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Gross number of share options (or share units) granted during the period.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross", "terseLabel": "Options, Granted" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue": { "auth_ref": [ "r298" ], "lang": { "en-US": { "role": { "documentation": "The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value", "terseLabel": "Grant date fair value per share", "verboseLabel": "Grant date fair value per share of option awards" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue": { "auth_ref": [ "r310" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value", "terseLabel": "Aggregate Intrinsic Value, Outstanding at March 31, 2020" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber": { "auth_ref": [ "r288", "r310" ], "lang": { "en-US": { "role": { "documentation": "Number of options outstanding, including both vested and non-vested options.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number", "periodEndLabel": "Options, Outstanding at March 31, 2020", "periodStartLabel": "Options, Outstanding at December 31, 2019" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice": { "auth_ref": [ "r287" ], "lang": { "en-US": { "role": { "documentation": "Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.", "label": "Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price", "periodEndLabel": "Weighted Average Exercise Price per Option, Outstanding at March 31, 2020", "periodStartLabel": "Weighted Average Exercise Price per Option, Outstanding at December 31, 2019" } } }, "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain": { "auth_ref": [ "r279", "r285" ], "lang": { "en-US": { "role": { "documentation": "Award under share-based payment arrangement.", "label": "Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain]", "terseLabel": "Award Type" } } }, "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationPerformanceAwardFairValueAssumptionsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfPerformanceStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfNonVestedStockUnitsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationTables" ], "xbrltype": "domainItemType" }, "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.", "label": "Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price", "terseLabel": "Weighted Average Exercise Price per Option, Expired" } } }, "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.", "label": "Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price", "terseLabel": "Weighted Average Exercise Price per Option, Forfeited" } } }, "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.", "label": "Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price", "terseLabel": "Weighted Average Exercise Price per Option, Granted" } } }, "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "perShareItemType" }, "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage": { "auth_ref": [ "r283" ], "lang": { "en-US": { "role": { "documentation": "Percentage of vesting of award under share-based payment arrangement.", "label": "Sharebased Compensation Arrangement By Sharebased Payment Award Award Vesting Rights Percentage", "terseLabel": "Vesting percentage" } } }, "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "percentItemType" }, "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod": { "auth_ref": [ "r284" ], "lang": { "en-US": { "role": { "documentation": "Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.", "label": "Sharebased Compensation Arrangement By Sharebased Payment Award Expiration Period", "terseLabel": "Stock options, term in years" } } }, "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" ], "xbrltype": "durationItemType" }, "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1": { "auth_ref": [ "r302", "r311" ], "lang": { "en-US": { "role": { "documentation": "Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.", "label": "Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1", "terseLabel": "Expected life in years" } } }, "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationStockOptionsFairValueAssumptionsDetail" ], "xbrltype": "durationItemType" }, "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1": { "auth_ref": [ "r310" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.", "label": "Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1", "terseLabel": "Aggregate Intrinsic Value, Exercisable at March 31, 2020" } } }, "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1": { "auth_ref": [ "r310" ], "lang": { "en-US": { "role": { "documentation": "Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.", "label": "Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1", "terseLabel": "Weighted Average Remaining Contractual Term, Exercisable at March 31, 2020" } } }, "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "durationItemType" }, "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2": { "auth_ref": [ "r300" ], "lang": { "en-US": { "role": { "documentation": "Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.", "label": "Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2", "terseLabel": "Weighted Average Remaining Contractual Term, Outstanding at March 31, 2020" } } }, "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStatusAndActivityOfStockOptionsDetail" ], "xbrltype": "durationItemType" }, "us-gaap_SiteContingencyRecoveryFromThirdPartyOfEnvironmentalRemediationCost": { "auth_ref": [ "r202", "r204" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of the estimated recovery from third parties recorded in the period for an individual site that reduces environmental remediation expense.", "label": "Site Contingency Recovery From Third Party Of Environmental Remediation Cost", "terseLabel": "Environmental remediation costs paid by others, per year" } } }, "localname": "SiteContingencyRecoveryFromThirdPartyOfEnvironmentalRemediationCost", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_StatementBusinessSegmentsAxis": { "auth_ref": [ "r10", "r147", "r181", "r192", "r210", "r217", "r442" ], "lang": { "en-US": { "role": { "documentation": "Information by business segments.", "label": "Statement Business Segments [Axis]", "terseLabel": "Segments" } } }, "localname": "StatementBusinessSegmentsAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingentLiabilitiesAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationScheduleOfSegmentRevenuesForSignificantProductLinesDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfResultsOfSegmentOperationsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureSegmentInformationSummaryOfTangibleAndIntangibleAssetsBySegmentsParentheticalDetail" ], "xbrltype": "stringItemType" }, "us-gaap_StatementEquityComponentsAxis": { "auth_ref": [ "r61", "r240" ], "lang": { "en-US": { "role": { "documentation": "Information by component of equity.", "label": "Statement Equity Components [Axis]", "terseLabel": "Equity Components" } } }, "localname": "StatementEquityComponentsAxis", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "stringItemType" }, "us-gaap_StatementOfCashFlowsAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Statement Of Cash Flows [Abstract]" } } }, "localname": "StatementOfCashFlowsAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_StatementOfFinancialPositionAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Statement Of Financial Position [Abstract]" } } }, "localname": "StatementOfFinancialPositionAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "xbrltype": "stringItemType" }, "us-gaap_StockIssuedDuringPeriodValueNewIssues": { "auth_ref": [ "r32", "r33", "r240", "r245" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.", "label": "Stock Issued During Period Value New Issues", "terseLabel": "Issuance of common stock" } } }, "localname": "StockIssuedDuringPeriodValueNewIssues", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation": { "auth_ref": [ "r32", "r33", "r245", "r281", "r298" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Value, after forfeiture, of shares issued under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).", "label": "Stock Issued During Period Value Share Based Compensation", "terseLabel": "Employee stock plans" } } }, "localname": "StockIssuedDuringPeriodValueShareBasedCompensation", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_StockholdersEquity": { "auth_ref": [ "r33", "r37", "r38", "r163" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10040.0, "parentTag": "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.", "label": "Stockholders Equity", "totalLabel": "Total Koppers shareholders\u2019 equity" } } }, "localname": "StockholdersEquity", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest": { "auth_ref": [ "r334", "r335", "r344" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10030.0, "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity", "weight": 1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.", "label": "Stockholders Equity Including Portion Attributable To Noncontrolling Interest", "periodEndLabel": "Balance", "periodStartLabel": "Balance", "totalLabel": "Total equity" } } }, "localname": "StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Stockholders Equity Including Portion Attributable To Noncontrolling Interest [Abstract]", "terseLabel": "Equity" } } }, "localname": "StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "stringItemType" }, "us-gaap_StockholdersEquityNoteDisclosureTextBlock": { "auth_ref": [ "r248" ], "lang": { "en-US": { "role": { "documentation": "The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.", "label": "Stockholders Equity Note Disclosure [Text Block]", "terseLabel": "Comprehensive Income and Equity" } } }, "localname": "StockholdersEquityNoteDisclosureTextBlock", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquity" ], "xbrltype": "textBlockItemType" }, "us-gaap_SwapMember": { "auth_ref": [ "r349" ], "lang": { "en-US": { "role": { "documentation": "A forward-based contract in which two parties agree to swap streams of payments over a specified period. The payment streams are based on an agreed-upon (or notional) principal amount. The term notional is used because swap contracts generally involve no exchange of principal at either inception or maturity. Rather, the notional amount serves as a basis for calculation of the payment streams to be exchanged.", "label": "Swap [Member]", "terseLabel": "Copper Swap Contracts [Member]" } } }, "localname": "SwapMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain": { "auth_ref": [ "r410" ], "lang": { "en-US": { "role": { "documentation": "Instrument or contract that imposes a contractual obligation to deliver cash or another financial instrument or to exchange other financial instruments on potentially unfavorable terms and conveys a contractual right to receive cash or another financial instrument or to exchange other financial instruments on potentially favorable terms.", "label": "Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain]", "terseLabel": "Financial Instruments" } } }, "localname": "TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingCopperSwapContractsRecordedInBalanceSheetDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfFairValueOfOutstandingForeignCurrencyForwardContractsDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfLossGainFromContractNotDesignatedAsHedgesDetail", "http://www.koppers.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsScheduleOfOutstandingCopperSwapContractsDetail" ], "xbrltype": "domainItemType" }, "us-gaap_TreasuryStockMember": { "auth_ref": [ "r60", "r246" ], "lang": { "en-US": { "role": { "documentation": "Shares of an entity that have been repurchased by the entity. This stock has no voting rights and receives no dividends. Note that treasury stock may be recorded at its total cost or separately as par (or stated) value and additional paid in capital. Classified within stockholders' equity if nonredeemable or redeemable solely at the option of the issuer. Classified within temporary equity if redemption is outside the control of the issuer.", "label": "Treasury Stock [Member]", "terseLabel": "Treasury Stock [Member]" } } }, "localname": "TreasuryStockMember", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "domainItemType" }, "us-gaap_TreasuryStockShares": { "auth_ref": [ "r60", "r246" ], "lang": { "en-US": { "role": { "documentation": "Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.", "label": "Treasury Stock Shares", "terseLabel": "Treasury stock, shares" } } }, "localname": "TreasuryStockShares", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetParenthetical" ], "xbrltype": "sharesItemType" }, "us-gaap_TreasuryStockValue": { "auth_ref": [ "r60", "r246", "r247" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet": { "order": 10110.0, "parentTag": "us-gaap_StockholdersEquity", "weight": -1.0 } }, "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "The amount allocated to treasury stock. Treasury stock is common and preferred shares of an entity that were issued, repurchased by the entity, and are held in its treasury.", "label": "Treasury Stock Value", "negatedLabel": "Treasury stock, at cost, 2,574,631 and 2,515,925 shares" } } }, "localname": "TreasuryStockValue", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedBalanceSheet" ], "xbrltype": "monetaryItemType" }, "us-gaap_TreasuryStockValueAcquiredCostMethod": { "auth_ref": [ "r240", "r245", "r246" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.", "label": "Treasury Stock Value Acquired Cost Method", "negatedLabel": "Repurchases of common stock" } } }, "localname": "TreasuryStockValueAcquiredCostMethod", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureComprehensiveIncomeAndEquityScheduleOfChangeInEquityDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_TypeOfRestructuringDomain": { "auth_ref": [], "lang": { "en-US": { "role": { "documentation": "Identification of the types of restructuring costs.", "label": "Type Of Restructuring [Domain]", "terseLabel": "Type of Restructuring" } } }, "localname": "TypeOfRestructuringDomain", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosurePlantClosuresAndDivestituresSummaryOfRestructuringActivitiesAndRelatedReservesDetail" ], "xbrltype": "domainItemType" }, "us-gaap_UnrecognizedTaxBenefits": { "auth_ref": [ "r314", "r324" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of unrecognized tax benefits.", "label": "Unrecognized Tax Benefits", "terseLabel": "Unrecognized tax benefits" } } }, "localname": "UnrecognizedTaxBenefits", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued": { "auth_ref": [ "r323" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.", "label": "Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued", "terseLabel": "Accrued interest expense and penalties" } } }, "localname": "UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate": { "auth_ref": [ "r325" ], "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.", "label": "Unrecognized Tax Benefits That Would Impact Effective Tax Rate", "terseLabel": "Unrecognized tax benefits with impact on the effective tax rate" } } }, "localname": "UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_UnusualOrInfrequentItemInsuranceProceeds": { "auth_ref": [ "r102" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited": { "order": 10200.0, "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities", "weight": -1.0 } }, "crdr": "credit", "lang": { "en-US": { "role": { "documentation": "Amount of insurance proceeds for an event or transaction that is unusual in nature or infrequent in occurrence, or both.", "label": "Unusual Or Infrequent Item Insurance Proceeds", "negatedLabel": "Insurance proceeds" } } }, "localname": "UnusualOrInfrequentItemInsuranceProceeds", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfCashFlowsUnaudited" ], "xbrltype": "monetaryItemType" }, "us-gaap_VariableLeaseCost": { "auth_ref": [ "r401", "r407" ], "crdr": "debit", "lang": { "en-US": { "role": { "documentation": "Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.", "label": "Variable Lease Cost", "terseLabel": "Variable lease costs" } } }, "localname": "VariableLeaseCost", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureLeasesAdditionalInformationDetail" ], "xbrltype": "monetaryItemType" }, "us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment": { "auth_ref": [ "r132" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail": { "order": 10020.0, "parentTag": "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.", "label": "Weighted Average Number Diluted Shares Outstanding Adjustment", "terseLabel": "Effect of dilutive securities" } } }, "localname": "WeightedAverageNumberDilutedSharesOutstandingAdjustment", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail" ], "xbrltype": "sharesItemType" }, "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding": { "auth_ref": [ "r127", "r132" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail": { "order": null, "parentTag": null, "root": true, "weight": null } }, "lang": { "en-US": { "role": { "documentation": "The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.", "label": "Weighted Average Number Of Diluted Shares Outstanding", "terseLabel": "Diluted", "totalLabel": "Diluted" } } }, "localname": "WeightedAverageNumberOfDilutedSharesOutstanding", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "sharesItemType" }, "us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract": { "auth_ref": [], "lang": { "en-US": { "role": { "label": "Weighted Average Number Of Shares Outstanding [Abstract]", "terseLabel": "Weighted average shares outstanding (in thousands):", "verboseLabel": "Weighted average common shares outstanding:" } } }, "localname": "WeightedAverageNumberOfSharesOutstandingAbstract", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "stringItemType" }, "us-gaap_WeightedAverageNumberOfSharesOutstandingBasic": { "auth_ref": [ "r126", "r132" ], "calculation": { "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail": { "order": 10010.0, "parentTag": "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding", "weight": 1.0 } }, "lang": { "en-US": { "role": { "documentation": "Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.", "label": "Weighted Average Number Of Shares Outstanding Basic", "terseLabel": "Basic" } } }, "localname": "WeightedAverageNumberOfSharesOutstandingBasic", "nsuri": "http://fasb.org/us-gaap/2019-01-31", "presentation": [ "http://www.koppers.com/20200331/taxonomy/role/DisclosureEarningsPerCommonShareScheduleOfComputationOfBasicAndDilutedEarningsPerCommonShareDetail", "http://www.koppers.com/20200331/taxonomy/role/StatementCondensedConsolidatedStatementOfOperationsAndComprehensiveIncomeUnaudited" ], "xbrltype": "sharesItemType" } }, "unitCount": 16 } }, "std_ref": { "r0": { "Name": "Accounting Standards Codification", "Paragraph": "10", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=d3e1107-107759" }, "r1": { "Name": "Accounting Standards Codification", "Paragraph": "11", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=SL51721533-107759" }, "r10": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(d)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=d3e1361-107760" }, "r100": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03.8)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r101": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r102": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=114868883&loc=SL114871943-224233" }, "r103": { "Name": "Accounting Standards Codification", "Paragraph": "12", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585" }, "r104": { "Name": "Accounting Standards Codification", "Paragraph": "13", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585" }, "r105": { "Name": "Accounting Standards Codification", "Paragraph": "14", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585" }, "r106": { "Name": "Accounting Standards Codification", "Paragraph": "15", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585" }, "r107": { "Name": "Accounting Standards Codification", "Paragraph": "15", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585" }, "r108": { "Name": "Accounting Standards Codification", "Paragraph": "15", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(e)", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585" }, "r109": { "Name": "Accounting Standards Codification", "Paragraph": "17", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(e)", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585" }, "r11": { "Name": "Accounting Standards Codification", "Paragraph": "5B", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760" }, "r110": { "Name": "Accounting Standards Codification", "Paragraph": "17", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(f)", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585" }, "r111": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3000-108585" }, "r112": { "Name": "Accounting Standards Codification", "Paragraph": "24", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3521-108585" }, "r113": { "Name": "Accounting Standards Codification", "Paragraph": "25", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3536-108585" }, "r114": { "Name": "Accounting Standards Codification", "Paragraph": "28", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585" }, "r115": { "Name": "Accounting Standards Codification", "Paragraph": "28", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585" }, "r116": { "Name": "Accounting Standards Codification", "Paragraph": "28", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585" }, "r117": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "230", "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3044-108585" }, "r118": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.4-08(h))", "Topic": "235", "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690" }, "r119": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.4-08(m)(1)(iii))", "Topic": "235", "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690" }, "r12": { "Name": "Accounting Standards Codification", "Paragraph": "5B", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(b)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760" }, "r120": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.4-08.(e),(f))", "Topic": "235", "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690" }, "r121": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.4-08.(h)(2))", "Topic": "235", "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690" }, "r122": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.4-08.(n)(2))", "Topic": "235", "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690" }, "r123": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.12-04(a))", "Topic": "235", "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690" }, "r124": { "Name": "Accounting Standards Codification", "Paragraph": "11", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "250", "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794" }, "r125": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "250", "URI": "http://asc.fasb.org/topic&trid=2122394" }, "r126": { "Name": "Accounting Standards Codification", "Paragraph": "10", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1448-109256" }, "r127": { "Name": "Accounting Standards Codification", "Paragraph": "16", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1505-109256" }, "r128": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1252-109256" }, "r129": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1278-109256" }, "r13": { "Name": "Accounting Standards Codification", "Paragraph": "5B", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(c)(1)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760" }, "r130": { "Name": "Accounting Standards Codification", "Paragraph": "60B", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(d)", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=SL5780133-109256" }, "r131": { "Name": "Accounting Standards Codification", "Paragraph": "7", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1337-109256" }, "r132": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257" }, "r133": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257" }, "r134": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257" }, "r135": { "Name": "Accounting Standards Codification", "Paragraph": "52", "Publisher": "FASB", "Section": "55", "SubTopic": "10", "Topic": "260", "URI": "http://asc.fasb.org/extlink&oid=117327953&loc=d3e4984-109258" }, "r136": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "260", "URI": "http://asc.fasb.org/topic&trid=2144383" }, "r137": { "Name": "Accounting Standards Codification", "Paragraph": "13", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8615-108599" }, "r138": { "Name": "Accounting Standards Codification", "Paragraph": "14", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8654-108599" }, "r139": { "Name": "Accounting Standards Codification", "Paragraph": "15", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8657-108599" }, "r14": { "Name": "Accounting Standards Codification", "Paragraph": "5B", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(e)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760" }, "r140": { "Name": "Accounting Standards Codification", "Paragraph": "16", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8660-108599" }, "r141": { "Name": "Accounting Standards Codification", "Paragraph": "17", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8663-108599" }, "r142": { "Name": "Accounting Standards Codification", "Paragraph": "18", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8672-108599" }, "r143": { "Name": "Accounting Standards Codification", "Paragraph": "21", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8721-108599" }, "r144": { "Name": "Accounting Standards Codification", "Paragraph": "22", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599" }, "r145": { "Name": "Accounting Standards Codification", "Paragraph": "22", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(d)", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599" }, "r146": { "Name": "Accounting Standards Codification", "Paragraph": "22", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(h)", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599" }, "r147": { "Name": "Accounting Standards Codification", "Paragraph": "22", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599" }, "r148": { "Name": "Accounting Standards Codification", "Paragraph": "25", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8813-108599" }, "r149": { "Name": "Accounting Standards Codification", "Paragraph": "30", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8906-108599" }, "r15": { "Name": "Accounting Standards Codification", "Paragraph": "5C", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)(2)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721675-107760" }, "r150": { "Name": "Accounting Standards Codification", "Paragraph": "30", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8906-108599" }, "r151": { "Name": "Accounting Standards Codification", "Paragraph": "30", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8906-108599" }, "r152": { "Name": "Accounting Standards Codification", "Paragraph": "31", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8924-108599" }, "r153": { "Name": "Accounting Standards Codification", "Paragraph": "32", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599" }, "r154": { "Name": "Accounting Standards Codification", "Paragraph": "32", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599" }, "r155": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8475-108599" }, "r156": { "Name": "Accounting Standards Codification", "Paragraph": "40", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9031-108599" }, "r157": { "Name": "Accounting Standards Codification", "Paragraph": "41", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "280", "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9038-108599" }, "r158": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "280", "URI": "http://asc.fasb.org/topic&trid=2134510" }, "r159": { "Name": "Accounting Standards Codification", "Paragraph": "13", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "310", "URI": "http://asc.fasb.org/extlink&oid=118952595&loc=d3e4647-111522" }, "r16": { "Name": "Accounting Standards Codification", "Paragraph": "5C", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(b)(2)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721675-107760" }, "r160": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "310", "URI": "http://asc.fasb.org/extlink&oid=118952595&loc=d3e4428-111522" }, "r161": { "Name": "Accounting Standards Codification", "Paragraph": "9", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "310", "URI": "http://asc.fasb.org/extlink&oid=118952595&loc=d3e4531-111522" }, "r162": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "310", "URI": "http://asc.fasb.org/extlink&oid=118936363&loc=d3e5074-111524" }, "r163": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB Topic 4.E)", "Topic": "310", "URI": "http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707" }, "r164": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)(1)", "Topic": "323", "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571" }, "r165": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)(b)", "Topic": "323", "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571" }, "r166": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=118955202&loc=SL82895884-210446" }, "r167": { "Name": "Accounting Standards Codification", "Paragraph": "11", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919244-210447" }, "r168": { "Name": "Accounting Standards Codification", "Paragraph": "13", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447" }, "r169": { "Name": "Accounting Standards Codification", "Paragraph": "14", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919253-210447" }, "r17": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "SubTopic": "20", "Topic": "205", "URI": "http://asc.fasb.org/subtopic&trid=2122178" }, "r170": { "Name": "Accounting Standards Codification", "Paragraph": "16", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919258-210447" }, "r171": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919230-210447" }, "r172": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=118955579&loc=SL82922888-210455" }, "r173": { "Name": "Accounting Standards Codification", "Paragraph": "7", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=118955579&loc=SL82922895-210455" }, "r174": { "Name": "Accounting Standards Codification", "Paragraph": "9", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=118955579&loc=SL82922900-210455" }, "r175": { "Name": "Accounting Standards Codification", "Paragraph": "8", "Publisher": "FASB", "Section": "55", "SubTopic": "30", "Topic": "326", "URI": "http://asc.fasb.org/extlink&oid=118942371&loc=SL82922954-210456" }, "r176": { "Name": "Accounting Standards Codification", "Paragraph": "8", "Publisher": "FASB", "Section": "30", "SubTopic": "10", "Topic": "330", "URI": "http://asc.fasb.org/extlink&oid=68048583&loc=d3e3636-108311" }, "r177": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "35", "SubTopic": "10", "Topic": "330", "URI": "http://asc.fasb.org/extlink&oid=116846819&loc=d3e3927-108312" }, "r178": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "330", "URI": "http://asc.fasb.org/topic&trid=2126998" }, "r179": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "350", "URI": "http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266" }, "r18": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "205", "URI": "http://asc.fasb.org/topic&trid=2122149" }, "r180": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "350", "URI": "http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975" }, "r181": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "350", "URI": "http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267" }, "r182": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Subparagraph": "(a)(1)", "Topic": "350", "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275" }, "r183": { "Name": "Accounting Standards Codification", "Paragraph": "11", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=109226348&loc=d3e2510-110228" }, "r184": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228" }, "r185": { "Name": "Accounting Standards Codification", "Paragraph": "9", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=109226348&loc=d3e2473-110228" }, "r186": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229" }, "r187": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229" }, "r188": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229" }, "r189": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229" }, "r19": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765" }, "r190": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(d)", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230" }, "r191": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(e)", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230" }, "r192": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(f)", "Topic": "360", "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230" }, "r193": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "360", "URI": "http://asc.fasb.org/topic&trid=2155823" }, "r194": { "Name": "Accounting Standards Codification", "Paragraph": "8", "Publisher": "FASB", "Section": "35", "SubTopic": "20", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6392603&loc=d3e7123-110846" }, "r195": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848" }, "r196": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(c)", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849" }, "r197": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(c)(3)", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849" }, "r198": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(c)(4)", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849" }, "r199": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "SubTopic": "20", "Topic": "410", "URI": "http://asc.fasb.org/subtopic&trid=2175671" }, "r2": { "Name": "Accounting Standards Codification", "Paragraph": "1B", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Subparagraph": "(a)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=SL51721494-107759" }, "r20": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765" }, "r200": { "Name": "Accounting Standards Codification", "Paragraph": "10", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Subparagraph": "(d)", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859" }, "r201": { "Name": "Accounting Standards Codification", "Paragraph": "10", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Subparagraph": "(d)(1)", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859" }, "r202": { "Name": "Accounting Standards Codification", "Paragraph": "10", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Subparagraph": "(d)(3)", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859" }, "r203": { "Name": "Accounting Standards Codification", "Paragraph": "11", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13283-110859" }, "r204": { "Name": "Accounting Standards Codification", "Paragraph": "12", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Subparagraph": "(b)", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13296-110859" }, "r205": { "Name": "Accounting Standards Codification", "Paragraph": "12", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13296-110859" }, "r206": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13201-110859" }, "r207": { "Name": "Accounting Standards Codification", "Paragraph": "7", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Topic": "410", "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859" }, "r208": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869" }, "r209": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)(2)", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869" }, "r21": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765" }, "r210": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(d)", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869" }, "r211": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869" }, "r212": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB TOPIC 5.P.3)", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140864-122747" }, "r213": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB TOPIC 5.P.4(b)(2))", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747" }, "r214": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB TOPIC 5.P.4(b))", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747" }, "r215": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB TOPIC 5.P.4)", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747" }, "r216": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB Topic 5.P.4(b)(2))", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747" }, "r217": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB Topic 5.P.4(d))", "Topic": "420", "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747" }, "r218": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "440", "URI": "http://asc.fasb.org/topic&trid=2144648" }, "r219": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "25", "SubTopic": "20", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346" }, "r22": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765" }, "r220": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349" }, "r221": { "Name": "Accounting Standards Codification", "Paragraph": "10", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14615-108349" }, "r222": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14394-108349" }, "r223": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14435-108349" }, "r224": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14435-108349" }, "r225": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14453-108349" }, "r226": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14472-108349" }, "r227": { "Name": "Accounting Standards Codification", "Paragraph": "9", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14557-108349" }, "r228": { "Name": "Accounting Standards Codification", "Paragraph": "9", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14557-108349" }, "r229": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "20", "Subparagraph": "(SAB TOPIC 5.Y.Q1)", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751" }, "r23": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6801-107765" }, "r230": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "20", "Subparagraph": "(SAB TOPIC 5.Y.Q2)", "Topic": "450", "URI": "http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751" }, "r231": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "450", "URI": "http://asc.fasb.org/topic&trid=2127136" }, "r232": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "15", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "460", "URI": "http://asc.fasb.org/extlink&oid=99404985&loc=d3e10037-110241" }, "r233": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "460", "URI": "http://asc.fasb.org/extlink&oid=118943654&loc=d3e12021-110248" }, "r234": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "460", "URI": "http://asc.fasb.org/extlink&oid=118943654&loc=d3e12053-110248" }, "r235": { "Name": "Accounting Standards Codification", "Paragraph": "13", "Publisher": "FASB", "Section": "55", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "460", "URI": "http://asc.fasb.org/extlink&oid=118956092&loc=d3e13051-110250" }, "r236": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "470", "URI": "http://asc.fasb.org/extlink&oid=6802200&loc=SL6230698-112601" }, "r237": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(b)(2)", "Topic": "470", "URI": "http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870" }, "r238": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(b)(3)", "Topic": "470", "URI": "http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870" }, "r239": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "470", "URI": "http://asc.fasb.org/topic&trid=2208564" }, "r24": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6911-107765" }, "r240": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "505", "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644" }, "r241": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "505", "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644" }, "r242": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "505", "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644" }, "r243": { "Name": "Accounting Standards Codification", "Paragraph": "7", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "505", "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644" }, "r244": { "Name": "Accounting Standards Codification", "Paragraph": "8", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "505", "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644" }, "r245": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.3-04)", "Topic": "505", "URI": "http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770" }, "r246": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "30", "Topic": "505", "URI": "http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655" }, "r247": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Topic": "505", "URI": "http://asc.fasb.org/extlink&oid=6405834&loc=d3e23315-112656" }, "r248": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "505", "URI": "http://asc.fasb.org/topic&trid=2208762" }, "r249": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "606", "URI": "http://asc.fasb.org/extlink&oid=118944033&loc=SL49130531-203044" }, "r25": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6361739&loc=d3e7789-107766" }, "r250": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "606", "URI": "http://asc.fasb.org/extlink&oid=118944033&loc=SL49130533-203044" }, "r251": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "606", "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045" }, "r252": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "606", "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045" }, "r253": { "Name": "Accounting Standards Codification", "Paragraph": "8", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "606", "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045" }, "r254": { "Name": "Accounting Standards Codification", "Paragraph": "91", "Publisher": "FASB", "Section": "55", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "606", "URI": "http://asc.fasb.org/extlink&oid=118944142&loc=SL49130690-203046-203046" }, "r255": { "Name": "Accounting Standards Codification", "Paragraph": "91", "Publisher": "FASB", "Section": "55", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "606", "URI": "http://asc.fasb.org/extlink&oid=118944142&loc=SL49130690-203046-203046" }, "r256": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=109237824&loc=d3e1703-114919" }, "r257": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=109237824&loc=d3e1731-114919" }, "r258": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)(1)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r259": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)(2)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r26": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(13))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r260": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(c)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r261": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(h)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r262": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(h)(1)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r263": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(h)(2)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r264": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(h)(3)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r265": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(h)(4)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r266": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(i)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r267": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920" }, "r268": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2410-114920" }, "r269": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2417-114920" }, "r27": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(14))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r270": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2439-114920" }, "r271": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920" }, "r272": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)(1)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920" }, "r273": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)(2)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920" }, "r274": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)(3)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920" }, "r275": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)(4)", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920" }, "r276": { "Name": "Accounting Standards Codification", "Paragraph": "17", "Publisher": "FASB", "Section": "55", "SubTopic": "20", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921" }, "r277": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "70", "Topic": "715", "URI": "http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942" }, "r278": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "715", "URI": "http://asc.fasb.org/topic&trid=2235017" }, "r279": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901" }, "r28": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(19))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r280": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901" }, "r281": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901" }, "r282": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901" }, "r283": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)(1)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r284": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)(2)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r285": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a),(g)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r286": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(1)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r287": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(1)(i)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r288": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(1)(i)-(ii)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r289": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(1)(iii)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r29": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(20))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r290": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(1)(iv)(3)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r291": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(1)(iv)(4)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r292": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(2)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r293": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(2)(i)-(ii)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r294": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(2)(iii)(1)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r295": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(2)(iii)(2)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r296": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(2)(iii)(3)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r297": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(d)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r298": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(d)(1)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r299": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(e)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r3": { "Name": "Accounting Standards Codification", "Paragraph": "1B", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Subparagraph": "(c)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=SL51721494-107759" }, "r30": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(22))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r300": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(e)(1)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r301": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(f)(2)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r302": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(f)(2)(i)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r303": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(f)(2)(ii)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r304": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(f)(2)(iii)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r305": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(f)(2)(iv)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r306": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(g)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r307": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(h)(1)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r308": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(h)(1)(i)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r309": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(i)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r31": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(24))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r310": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901" }, "r311": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB Topic 14.D.2)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809" }, "r312": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB Topic 14.F)", "Topic": "718", "URI": "http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809" }, "r313": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "718", "URI": "http://asc.fasb.org/topic&trid=2228938" }, "r314": { "Name": "Accounting Standards Codification", "Paragraph": "10B", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=SL37586934-109318" }, "r315": { "Name": "Accounting Standards Codification", "Paragraph": "20", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e32123-109318" }, "r316": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e31917-109318" }, "r317": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e31928-109318" }, "r318": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e31931-109318" }, "r319": { "Name": "Accounting Standards Codification", "Paragraph": "9", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e31958-109318" }, "r32": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(28))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r320": { "Name": "Accounting Standards Codification", "Paragraph": "10", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32672-109319" }, "r321": { "Name": "Accounting Standards Codification", "Paragraph": "12", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319" }, "r322": { "Name": "Accounting Standards Codification", "Paragraph": "13", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319" }, "r323": { "Name": "Accounting Standards Codification", "Paragraph": "15", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319" }, "r324": { "Name": "Accounting Standards Codification", "Paragraph": "15A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319" }, "r325": { "Name": "Accounting Standards Codification", "Paragraph": "15A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319" }, "r326": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319" }, "r327": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319" }, "r328": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB TOPIC 6.I)", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817" }, "r329": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Subparagraph": "(a)", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324" }, "r33": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(29))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r330": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "740", "URI": "http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324" }, "r331": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "740", "URI": "http://asc.fasb.org/topic&trid=2144680" }, "r332": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "805", "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463" }, "r333": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "805", "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1486-128463" }, "r334": { "Name": "Accounting Standards Codification", "Paragraph": "15", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4568447-111683" }, "r335": { "Name": "Accounting Standards Codification", "Paragraph": "16", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4568740-111683" }, "r336": { "Name": "Accounting Standards Codification", "Paragraph": "18", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4613673-111683" }, "r337": { "Name": "Accounting Standards Codification", "Paragraph": "19", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683" }, "r338": { "Name": "Accounting Standards Codification", "Paragraph": "20", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4569643-111683" }, "r339": { "Name": "Accounting Standards Codification", "Paragraph": "21", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4613674-111683" }, "r34": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(3))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r340": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)(1)", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684" }, "r341": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)(2)", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684" }, "r342": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(1)", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684" }, "r343": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c),(3)", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684" }, "r344": { "Name": "Accounting Standards Codification", "Paragraph": "4I", "Publisher": "FASB", "Section": "55", "SubTopic": "10", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4590271-111686" }, "r345": { "Name": "Accounting Standards Codification", "Paragraph": "4J", "Publisher": "FASB", "Section": "55", "SubTopic": "10", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4591551-111686" }, "r346": { "Name": "Accounting Standards Codification", "Paragraph": "4K", "Publisher": "FASB", "Section": "55", "SubTopic": "10", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4591552-111686" }, "r347": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SAB Topic 5.E)", "Topic": "810", "URI": "http://asc.fasb.org/extlink&oid=116822174&loc=d3e355146-122828" }, "r348": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "810", "URI": "http://asc.fasb.org/topic&trid=2197479" }, "r349": { "Name": "Accounting Standards Codification", "Paragraph": "83", "Publisher": "FASB", "Section": "15", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=117415099&loc=d3e34841-113949" }, "r35": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(30)(a)(1))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r350": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=117331979&loc=d3e41228-113958" }, "r351": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5579240-113959" }, "r352": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959" }, "r353": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(d)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959" }, "r354": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959" }, "r355": { "Name": "Accounting Standards Codification", "Paragraph": "1B", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959" }, "r356": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)(1)(ii)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=d3e41620-113959" }, "r357": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=d3e41620-113959" }, "r358": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "c", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=d3e41638-113959" }, "r359": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=d3e41638-113959" }, "r36": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(30)(a)(3))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r360": { "Name": "Accounting Standards Codification", "Paragraph": "4A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959" }, "r361": { "Name": "Accounting Standards Codification", "Paragraph": "4A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959" }, "r362": { "Name": "Accounting Standards Codification", "Paragraph": "4B", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(c)(2)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959" }, "r363": { "Name": "Accounting Standards Codification", "Paragraph": "4B", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(d)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959" }, "r364": { "Name": "Accounting Standards Codification", "Paragraph": "4B", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959" }, "r365": { "Name": "Accounting Standards Codification", "Paragraph": "4C", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959" }, "r366": { "Name": "Accounting Standards Codification", "Paragraph": "4C", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(e)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959" }, "r367": { "Name": "Accounting Standards Codification", "Paragraph": "4C", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959" }, "r368": { "Name": "Accounting Standards Codification", "Paragraph": "4CC", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL109998890-113959" }, "r369": { "Name": "Accounting Standards Codification", "Paragraph": "4D", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959" }, "r37": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(30))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r370": { "Name": "Accounting Standards Codification", "Paragraph": "4E", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624181-113959" }, "r371": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=d3e41641-113959" }, "r372": { "Name": "Accounting Standards Codification", "Paragraph": "8", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=d3e41678-113959" }, "r373": { "Name": "Accounting Standards Codification", "Paragraph": "182", "Publisher": "FASB", "Section": "55", "SubTopic": "10", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=116861445&loc=SL5629052-113961" }, "r374": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "25", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109977999&loc=d3e76258-113986" }, "r375": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "30", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=109978405&loc=d3e80720-113993" }, "r376": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Subparagraph": "(d)", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994" }, "r377": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "50", "SubTopic": "30", "Topic": "815", "URI": "http://asc.fasb.org/extlink&oid=112277219&loc=d3e80845-113994" }, "r378": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "815", "URI": "http://asc.fasb.org/topic&trid=2229140" }, "r379": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "820", "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258" }, "r38": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(31))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r380": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(bbb)(2)", "Topic": "820", "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258" }, "r381": { "Name": "Accounting Standards Codification", "Paragraph": "6A", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "820", "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=SL6742756-110258" }, "r382": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "820", "URI": "http://asc.fasb.org/topic&trid=2155941" }, "r383": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "825", "URI": "http://asc.fasb.org/extlink&oid=116690757&loc=d3e13220-108610" }, "r384": { "Name": "Accounting Standards Codification", "Paragraph": "10", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "825", "URI": "http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611" }, "r385": { "Name": "Accounting Standards Codification", "Paragraph": "11", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "825", "URI": "http://asc.fasb.org/extlink&oid=118260190&loc=d3e13467-108611" }, "r386": { "Name": "Accounting Standards Codification", "Paragraph": "12", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "825", "URI": "http://asc.fasb.org/extlink&oid=118260190&loc=d3e13476-108611" }, "r387": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "230", "Topic": "830", "URI": "http://asc.fasb.org/extlink&oid=98513438&loc=d3e33268-110906" }, "r388": { "Name": "Accounting Standards Codification", "Paragraph": "20", "Publisher": "FASB", "Section": "45", "SubTopic": "30", "Subparagraph": "(b,c)", "Topic": "830", "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900" }, "r389": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "30", "Topic": "830", "URI": "http://asc.fasb.org/extlink&oid=6897108&loc=SL6897125-166521" }, "r39": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(32))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r390": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(a)", "Topic": "835", "URI": "http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391" }, "r391": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "45", "SubTopic": "30", "Topic": "835", "URI": "http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399" }, "r392": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "45", "SubTopic": "30", "Topic": "835", "URI": "http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399" }, "r393": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "45", "SubTopic": "30", "Topic": "835", "URI": "http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399" }, "r394": { "Name": "Accounting Standards Codification", "Paragraph": "8", "Publisher": "FASB", "Section": "55", "SubTopic": "30", "Topic": "835", "URI": "http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400" }, "r395": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "840", "URI": "http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717" }, "r396": { "Name": "Accounting Standards Codification", "Publisher": "FASB", "Topic": "840", "URI": "http://asc.fasb.org/topic&trid=2208923" }, "r397": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Subparagraph": "(a)", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977" }, "r398": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Subparagraph": "(b)", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977" }, "r399": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Subparagraph": "(c)", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918643-209977" }, "r4": { "Name": "Accounting Standards Codification", "Paragraph": "1D", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=SL51721503-107759" }, "r40": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(4)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r400": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(b)", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980" }, "r401": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(d)", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980" }, "r402": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(g)(1)", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980" }, "r403": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(g)(2)", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980" }, "r404": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(g)(3)", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980" }, "r405": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(g)(4)", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980" }, "r406": { "Name": "Accounting Standards Codification", "Paragraph": "6", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980" }, "r407": { "Name": "Accounting Standards Codification", "Paragraph": "53", "Publisher": "FASB", "Section": "55", "SubTopic": "20", "Topic": "842", "URI": "http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971" }, "r408": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "850", "URI": "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39599-107864" }, "r409": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "10", "Topic": "855", "URI": "http://asc.fasb.org/extlink&oid=6842918&loc=SL6314020-165662" }, "r41": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(6)(a))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r410": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "50", "Topic": "860", "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746" }, "r411": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "25", "SubTopic": "20", "Topic": "940", "URI": "http://asc.fasb.org/extlink&oid=68072869&loc=d3e41242-110953" }, "r412": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.9-03(11))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878" }, "r413": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.9-03(13))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878" }, "r414": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.9-03(16))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878" }, "r415": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.9-03(22))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878" }, "r416": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.9-03(23))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878" }, "r417": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.9-03.10)", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878" }, "r418": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.9-03.17)", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878" }, "r419": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.7-04(19))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260" }, "r42": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(6)(b))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r420": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.9-04(15))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260" }, "r421": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.9-04(20))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260" }, "r422": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.9-04(22))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260" }, "r423": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.9-04(23))", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260" }, "r424": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.9-04.9)", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260" }, "r425": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "470", "Subparagraph": "(c)", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823" }, "r426": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "470", "Subparagraph": "e", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823" }, "r427": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "50", "SubTopic": "470", "Topic": "942", "URI": "http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823" }, "r428": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.7-03(16))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910" }, "r429": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.7-03(a)(12))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910" }, "r43": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02(6)(c))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r430": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.7-03(a)(16))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910" }, "r431": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.7-03(a)(23)(a)(4))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910" }, "r432": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.7-03(a)(24))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910" }, "r433": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.7-03(a)(25))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910" }, "r434": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.7-03(a)(8))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910" }, "r435": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.7-03.(a),19)", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910" }, "r436": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "210", "Subparagraph": "(SX 210.7-03.5(c))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910" }, "r437": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.7-04(11))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263" }, "r438": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.7-04(12))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263" }, "r439": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.7-04(18))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263" }, "r44": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.1)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r440": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.7-04(19))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263" }, "r441": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "220", "Subparagraph": "(SX 210.7-04(8))", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263" }, "r442": { "Name": "Accounting Standards Codification", "Paragraph": "4H", "Publisher": "FASB", "Section": "50", "SubTopic": "40", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=116884468&loc=SL65671331-158438" }, "r443": { "Name": "Accounting Standards Codification", "Paragraph": "13H", "Publisher": "FASB", "Section": "55", "SubTopic": "40", "Subparagraph": "(a)", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=117419784&loc=SL117783719-158441" }, "r444": { "Name": "Accounting Standards Codification", "Paragraph": "13H", "Publisher": "FASB", "Section": "55", "SubTopic": "40", "Subparagraph": "(b)", "Topic": "944", "URI": "http://asc.fasb.org/extlink&oid=117419784&loc=SL117783719-158441" }, "r445": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "310", "Subparagraph": "(SX 210.12-29(Footnote 4))", "Topic": "948", "URI": "http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014" }, "r446": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "360", "Subparagraph": "(SX 210.12-28(Footnote 2))", "Topic": "970", "URI": "http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024" }, "r447": { "Name": "Exchange Act", "Number": "240", "Publisher": "SEC", "Section": "12", "Subsection": "b" }, "r448": { "Name": "Exchange Act", "Number": "240", "Publisher": "SEC", "Section": "12", "Subsection": "d1-1" }, "r449": { "Name": "Form 10-Q", "Number": "240", "Publisher": "SEC", "Section": "13", "Subsection": "a-13" }, "r45": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.13)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r450": { "Name": "Forms 10-K, 10-Q, 20-F", "Number": "240", "Publisher": "SEC", "Section": "13", "Subsection": "a-1-" }, "r451": { "Name": "Regulation 12B", "Number": "240", "Publisher": "SEC", "Section": "12", "Subsection": "b-2" }, "r452": { "Name": "Regulation S-T", "Number": "232", "Publisher": "SEC", "Section": "405" }, "r453": { "Name": "Regulation S-X (SX)", "Number": "210", "Publisher": "SEC", "Section": "11", "Subsection": "03" }, "r454": { "Footnote": "2", "Name": "Regulation S-X (SX)", "Number": "210", "Publisher": "SEC", "Section": "12", "Subsection": "28" }, "r455": { "Footnote": "4", "Name": "Regulation S-X (SX)", "Number": "210", "Publisher": "SEC", "Section": "12", "Subsection": "29" }, "r456": { "Name": "Regulation S-X (SX)", "Number": "210", "Paragraph": "i", "Publisher": "SEC", "Section": "3", "Subsection": "10" }, "r457": { "Name": "Regulation S-X (SX)", "Number": "210", "Paragraph": "(m)", "Publisher": "SEC", "Section": "4", "Subparagraph": "(1)(iii)", "Subsection": "08" }, "r46": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.14)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r47": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.17)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r48": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.19(a))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r49": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.19(b),22(b))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r5": { "Name": "Accounting Standards Codification", "Paragraph": "3", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=d3e957-107759" }, "r50": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.19,20)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r51": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.19-26)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r52": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.20)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r53": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.21)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r54": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.22(a)(2))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r55": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.22(a)(3))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r56": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.22(b))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r57": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.22)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r58": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.24)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r59": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.25)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r6": { "Name": "Accounting Standards Codification", "Paragraph": "3A", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=SL51721523-107759" }, "r60": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.29,30)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r61": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.29-31)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r62": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.3(a)(4))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r63": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.31)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r64": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.6(a)(1))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r65": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.6(a)(3))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r66": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.6(a)(4))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r67": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.6(a))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r68": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.6(c))", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r69": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.8)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r7": { "Name": "Accounting Standards Codification", "Paragraph": "3B", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=SL51721525-107759" }, "r70": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-02.9)", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682" }, "r71": { "Name": "Accounting Standards Codification", "Paragraph": "16", "Publisher": "FASB", "Section": "55", "SubTopic": "20", "Topic": "210", "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226024-175313" }, "r72": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e526-108580" }, "r73": { "Name": "Accounting Standards Codification", "Paragraph": "10A", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580" }, "r74": { "Name": "Accounting Standards Codification", "Paragraph": "10A", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(d)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580" }, "r75": { "Name": "Accounting Standards Codification", "Paragraph": "10A", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(i)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580" }, "r76": { "Name": "Accounting Standards Codification", "Paragraph": "10A", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580" }, "r77": { "Name": "Accounting Standards Codification", "Paragraph": "11", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580" }, "r78": { "Name": "Accounting Standards Codification", "Paragraph": "12", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e640-108580" }, "r79": { "Name": "Accounting Standards Codification", "Paragraph": "14", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e681-108580" }, "r8": { "Name": "Accounting Standards Codification", "Paragraph": "4", "Publisher": "FASB", "Section": "45", "SubTopic": "20", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=d3e1012-107759" }, "r80": { "Name": "Accounting Standards Codification", "Paragraph": "14A", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669686-108580" }, "r81": { "Name": "Accounting Standards Codification", "Paragraph": "15", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e689-108580" }, "r82": { "Name": "Accounting Standards Codification", "Paragraph": "17A", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL34724391-108580" }, "r83": { "Name": "Accounting Standards Codification", "Paragraph": "17B", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL34724394-108580" }, "r84": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580" }, "r85": { "Name": "Accounting Standards Codification", "Paragraph": "1A", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(c)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580" }, "r86": { "Name": "Accounting Standards Codification", "Paragraph": "1B", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(a)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580" }, "r87": { "Name": "Accounting Standards Codification", "Paragraph": "1B", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Subparagraph": "(b)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580" }, "r88": { "Name": "Accounting Standards Codification", "Paragraph": "5", "Publisher": "FASB", "Section": "45", "SubTopic": "10", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e557-108580" }, "r89": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03(13))", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868656-224227" }, "r9": { "Name": "Accounting Standards Codification", "Paragraph": "1", "Publisher": "FASB", "Section": "50", "SubTopic": "20", "Subparagraph": "(b)", "Topic": "205", "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=d3e1361-107760" }, "r90": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(210.5-03(11))", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r91": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03(10))", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r92": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03(14))", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r93": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03(20))", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r94": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03(21))", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r95": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03(8))", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r96": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03.13)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r97": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03.2(a),(d))", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r98": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03.4)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" }, "r99": { "Name": "Accounting Standards Codification", "Paragraph": "2", "Publisher": "FASB", "Section": "S99", "SubTopic": "10", "Subparagraph": "(SX 210.5-03.7)", "Topic": "220", "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227" } }, "version": "2.1" }