3.19.3.a.u2 html 203 423 1 false 60 0 false 8 false false R1.htm 0001001 - Document - Document and Entity Information Sheet http://www.greenhill.com/role/DocumentandEntityInformation Document and Entity Information Cover 1 false false R2.htm 1001002 - Statement - Consolidated Statements of Financial Condition Sheet http://www.greenhill.com/role/ConsolidatedStatementsofFinancialCondition Consolidated Statements of Financial Condition Statements 2 false false R3.htm 1002003 - Statement - Consolidated Statements of Financial Condition (Parenthetical) Sheet http://www.greenhill.com/role/ConsolidatedStatementsofFinancialConditionParenthetical Consolidated Statements of Financial Condition (Parenthetical) Statements 3 false false R4.htm 1003004 - Statement - Consolidated Statements of Operations Sheet http://www.greenhill.com/role/ConsolidatedStatementsofOperations Consolidated Statements of Operations Statements 4 false false R5.htm 1004005 - Statement - Consolidated Statements of Comprehensive Income Sheet http://www.greenhill.com/role/ConsolidatedStatementsofComprehensiveIncome Consolidated Statements of Comprehensive Income Statements 5 false false R6.htm 1005006 - Statement - Consolidated Statements of Changes in Stockholders' Equity Sheet http://www.greenhill.com/role/ConsolidatedStatementsofChangesinStockholdersEquity Consolidated Statements of Changes in Stockholders' Equity Statements 6 false false R7.htm 1006007 - Statement - Consolidated Statements of Changes in Equity (Parenthetical) Sheet http://www.greenhill.com/role/ConsolidatedStatementsofChangesinEquityParenthetical Consolidated Statements of Changes in Equity (Parenthetical) Statements 7 false false R8.htm 1007008 - Statement - Consolidated Statements of Cash Flows Sheet http://www.greenhill.com/role/ConsolidatedStatementsofCashFlows Consolidated Statements of Cash Flows Statements 8 false false R9.htm 2101101 - Disclosure - Organization Sheet http://www.greenhill.com/role/Organization Organization Notes 9 false false R10.htm 2103102 - Disclosure - Summary of Significant Accounting Policies Sheet http://www.greenhill.com/role/SummaryofSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 10 false false R11.htm 2106103 - Disclosure - Cash and Cash Equivalents Sheet http://www.greenhill.com/role/CashandCashEquivalents Cash and Cash Equivalents Notes 11 false false R12.htm 2110104 - Disclosure - Property and Equipment Sheet http://www.greenhill.com/role/PropertyandEquipment Property and Equipment Notes 12 false false R13.htm 2113105 - Disclosure - Goodwill Sheet http://www.greenhill.com/role/Goodwill Goodwill Notes 13 false false R14.htm 2117106 - Disclosure - Other Assets Sheet http://www.greenhill.com/role/OtherAssets Other Assets Notes 14 false false R15.htm 2120107 - Disclosure - Fair Value of Financial Instruments Sheet http://www.greenhill.com/role/FairValueofFinancialInstruments Fair Value of Financial Instruments Notes 15 false false R16.htm 2125108 - Disclosure - Related Parties Sheet http://www.greenhill.com/role/RelatedParties Related Parties Notes 16 false false R17.htm 2127109 - Disclosure - Loan Facilities Sheet http://www.greenhill.com/role/LoanFacilities Loan Facilities Notes 17 false false R18.htm 2131110 - Disclosure - Equity Sheet http://www.greenhill.com/role/Equity Equity Notes 18 false false R19.htm 2133111 - Disclosure - Earnings per Share Sheet http://www.greenhill.com/role/EarningsperShare Earnings per Share Notes 19 false false R20.htm 2137112 - Disclosure - Retirement Plan Sheet http://www.greenhill.com/role/RetirementPlan Retirement Plan Notes 20 false false R21.htm 2139113 - Disclosure - Deferred Compensation Sheet http://www.greenhill.com/role/DeferredCompensation Deferred Compensation Notes 21 false false R22.htm 2143114 - Disclosure - Commitments and Contingencies Sheet http://www.greenhill.com/role/CommitmentsandContingencies Commitments and Contingencies Notes 22 false false R23.htm 2145115 - Disclosure - Income Taxes Sheet http://www.greenhill.com/role/IncomeTaxes Income Taxes Notes 23 false false R24.htm 2151116 - Disclosure - Leases Sheet http://www.greenhill.com/role/Leases Leases Notes 24 false false R25.htm 2157117 - Disclosure - Regulatory Sheet http://www.greenhill.com/role/Regulatory Regulatory Notes 25 false false R26.htm 2159118 - Disclosure - Business Information Sheet http://www.greenhill.com/role/BusinessInformation Business Information Notes 26 false false R27.htm 2163119 - Disclosure - Subsequent Events Sheet http://www.greenhill.com/role/SubsequentEvents Subsequent Events Notes 27 false false R28.htm 2165120 - Disclosure - Supplemental Financial Information Quarterly Results (unaudited) Sheet http://www.greenhill.com/role/SupplementalFinancialInformationQuarterlyResultsunaudited Supplemental Financial Information Quarterly Results (unaudited) Notes 28 false false R29.htm 2204201 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://www.greenhill.com/role/SummaryofSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://www.greenhill.com/role/SummaryofSignificantAccountingPolicies 29 false false R30.htm 2307301 - Disclosure - Cash and Cash Equivalents (Tables) Sheet http://www.greenhill.com/role/CashandCashEquivalentsTables Cash and Cash Equivalents (Tables) Tables http://www.greenhill.com/role/CashandCashEquivalents 30 false false R31.htm 2311302 - Disclosure - Property and Equipment (Tables) Sheet http://www.greenhill.com/role/PropertyandEquipmentTables Property and Equipment (Tables) Tables http://www.greenhill.com/role/PropertyandEquipment 31 false false R32.htm 2314303 - Disclosure - Goodwill (Tables) Sheet http://www.greenhill.com/role/GoodwillTables Goodwill (Tables) Tables http://www.greenhill.com/role/Goodwill 32 false false R33.htm 2318304 - Disclosure - Other Assets (Tables) Sheet http://www.greenhill.com/role/OtherAssetsTables Other Assets (Tables) Tables http://www.greenhill.com/role/OtherAssets 33 false false R34.htm 2321305 - Disclosure - Fair Value of Financial Instruments (Tables) Sheet http://www.greenhill.com/role/FairValueofFinancialInstrumentsTables Fair Value of Financial Instruments (Tables) Tables http://www.greenhill.com/role/FairValueofFinancialInstruments 34 false false R35.htm 2328306 - Disclosure - Loan Facilities (Tables) Sheet http://www.greenhill.com/role/LoanFacilitiesTables Loan Facilities (Tables) Tables http://www.greenhill.com/role/LoanFacilities 35 false false R36.htm 2334307 - Disclosure - Earnings per Share (Tables) Sheet http://www.greenhill.com/role/EarningsperShareTables Earnings per Share (Tables) Tables http://www.greenhill.com/role/EarningsperShare 36 false false R37.htm 2340308 - Disclosure - Deferred Compensation (Tables) Sheet http://www.greenhill.com/role/DeferredCompensationTables Deferred Compensation (Tables) Tables http://www.greenhill.com/role/DeferredCompensation 37 false false R38.htm 2346309 - Disclosure - Income Taxes (Tables) Sheet http://www.greenhill.com/role/IncomeTaxesTables Income Taxes (Tables) Tables http://www.greenhill.com/role/IncomeTaxes 38 false false R39.htm 2352310 - Disclosure - Leases (Tables) Sheet http://www.greenhill.com/role/LeasesTables Leases (Tables) Tables http://www.greenhill.com/role/Leases 39 false false R40.htm 2360311 - Disclosure - Business Information (Tables) Sheet http://www.greenhill.com/role/BusinessInformationTables Business Information (Tables) Tables http://www.greenhill.com/role/BusinessInformation 40 false false R41.htm 2366312 - Disclosure - Supplemental Financial Information Quarterly Results (unaudited) (Tables) Sheet http://www.greenhill.com/role/SupplementalFinancialInformationQuarterlyResultsunauditedTables Supplemental Financial Information Quarterly Results (unaudited) (Tables) Tables http://www.greenhill.com/role/SupplementalFinancialInformationQuarterlyResultsunaudited 41 false false R42.htm 2402401 - Disclosure - Organization (Details) Sheet http://www.greenhill.com/role/OrganizationDetails Organization (Details) Details http://www.greenhill.com/role/Organization 42 false false R43.htm 2405402 - Disclosure - Summary of Significant Accounting Policies (Details) Sheet http://www.greenhill.com/role/SummaryofSignificantAccountingPoliciesDetails Summary of Significant Accounting Policies (Details) Details http://www.greenhill.com/role/SummaryofSignificantAccountingPoliciesPolicies 43 false false R44.htm 2408403 - Disclosure - Cash and Cash Equivalents (Details) Sheet http://www.greenhill.com/role/CashandCashEquivalentsDetails Cash and Cash Equivalents (Details) Details http://www.greenhill.com/role/CashandCashEquivalentsTables 44 false false R45.htm 2409404 - Disclosure - Cash and Cash Equivalents - Narrative (Details) Sheet http://www.greenhill.com/role/CashandCashEquivalentsNarrativeDetails Cash and Cash Equivalents - Narrative (Details) Details 45 false false R46.htm 2412405 - Disclosure - Property and Equipment - Components of Property and Equipment (Details) Sheet http://www.greenhill.com/role/PropertyandEquipmentComponentsofPropertyandEquipmentDetails Property and Equipment - Components of Property and Equipment (Details) Details 46 false false R47.htm 2415406 - Disclosure - Goodwill - Changes in Carrying Value (Details) Sheet http://www.greenhill.com/role/GoodwillChangesinCarryingValueDetails Goodwill - Changes in Carrying Value (Details) Details 47 false false R48.htm 2416407 - Disclosure - Goodwill - Additional Information (Details) Sheet http://www.greenhill.com/role/GoodwillAdditionalInformationDetails Goodwill - Additional Information (Details) Details 48 false false R49.htm 2419408 - Disclosure - Other Assets - Components of Other Assets (Details) Sheet http://www.greenhill.com/role/OtherAssetsComponentsofOtherAssetsDetails Other Assets - Components of Other Assets (Details) Details 49 false false R50.htm 2422409 - Disclosure - Fair Value of Financial Instruments - Fair Value on a Recurring Basis (Details) Sheet http://www.greenhill.com/role/FairValueofFinancialInstrumentsFairValueonaRecurringBasisDetails Fair Value of Financial Instruments - Fair Value on a Recurring Basis (Details) Details 50 false false R51.htm 2423410 - Disclosure - Fair Value of Financial Instruments - Changes in Level 3 Liabilities (Details) Sheet http://www.greenhill.com/role/FairValueofFinancialInstrumentsChangesinLevel3LiabilitiesDetails Fair Value of Financial Instruments - Changes in Level 3 Liabilities (Details) Details 51 false false R52.htm 2424411 - Disclosure - Fair Value of Financial Instruments - Narrative (Details) Sheet http://www.greenhill.com/role/FairValueofFinancialInstrumentsNarrativeDetails Fair Value of Financial Instruments - Narrative (Details) Details 52 false false R53.htm 2426412 - Disclosure - Related Parties (Details) Sheet http://www.greenhill.com/role/RelatedPartiesDetails Related Parties (Details) Details http://www.greenhill.com/role/RelatedParties 53 false false R54.htm 2429413 - Disclosure - Loan Facilities - Additional Information (Detail) Sheet http://www.greenhill.com/role/LoanFacilitiesAdditionalInformationDetail Loan Facilities - Additional Information (Detail) Details 54 false false R55.htm 2430414 - Disclosure - Loan Facilities - Schedule of Debt (Details) Sheet http://www.greenhill.com/role/LoanFacilitiesScheduleofDebtDetails Loan Facilities - Schedule of Debt (Details) Details 55 false false R56.htm 2432415 - Disclosure - Equity (Details) Sheet http://www.greenhill.com/role/EquityDetails Equity (Details) Details http://www.greenhill.com/role/Equity 56 false false R57.htm 2435416 - Disclosure - Earnings per Share - Reconciliation (Details) Sheet http://www.greenhill.com/role/EarningsperShareReconciliationDetails Earnings per Share - Reconciliation (Details) Details 57 false false R58.htm 2436417 - Disclosure - Earnings per Share - Additional Information (Details) Sheet http://www.greenhill.com/role/EarningsperShareAdditionalInformationDetails Earnings per Share - Additional Information (Details) Details 58 false false R59.htm 2438418 - Disclosure - Retirement Plan (Details) Sheet http://www.greenhill.com/role/RetirementPlanDetails Retirement Plan (Details) Details http://www.greenhill.com/role/RetirementPlan 59 false false R60.htm 2441419 - Disclosure - Deferred Compensation - Additional Information (Detail) Sheet http://www.greenhill.com/role/DeferredCompensationAdditionalInformationDetail Deferred Compensation - Additional Information (Detail) Details 60 false false R61.htm 2442420 - Disclosure - Deferred Compensation - Activity (Detail) Sheet http://www.greenhill.com/role/DeferredCompensationActivityDetail Deferred Compensation - Activity (Detail) Details 61 false false R62.htm 2444421 - Disclosure - Commitments and Contingencies - Additional Information (Detail) Sheet http://www.greenhill.com/role/CommitmentsandContingenciesAdditionalInformationDetail Commitments and Contingencies - Additional Information (Detail) Details 62 false false R63.htm 2447422 - Disclosure - Income Taxes - Provision for Income Taxes (Details) Sheet http://www.greenhill.com/role/IncomeTaxesProvisionforIncomeTaxesDetails Income Taxes - Provision for Income Taxes (Details) Details 63 false false R64.htm 2448423 - Disclosure - Income Taxes - Additional Information (Detail) Sheet http://www.greenhill.com/role/IncomeTaxesAdditionalInformationDetail Income Taxes - Additional Information (Detail) Details 64 false false R65.htm 2449424 - Disclosure - Income Taxes - Net Deferred Tax Assets and Liabilities (Details) Sheet http://www.greenhill.com/role/IncomeTaxesNetDeferredTaxAssetsandLiabilitiesDetails Income Taxes - Net Deferred Tax Assets and Liabilities (Details) Details 65 false false R66.htm 2450425 - Disclosure - Income Taxes - Reconciliation of Statutory U.S. Federal Income Tax Rate to Company's Effective Income Tax Rate (Details) Sheet http://www.greenhill.com/role/IncomeTaxesReconciliationofStatutoryUSFederalIncomeTaxRatetoCompanysEffectiveIncomeTaxRateDetails Income Taxes - Reconciliation of Statutory U.S. Federal Income Tax Rate to Company's Effective Income Tax Rate (Details) Details 66 false false R67.htm 2453426 - Disclosure - Leases - Narrative (Details) Sheet http://www.greenhill.com/role/LeasesNarrativeDetails Leases - Narrative (Details) Details 67 false false R68.htm 2454427 - Disclosure - Leases - Operating lease,future rental payments, maturity (Details) Sheet http://www.greenhill.com/role/LeasesOperatingleasefuturerentalpaymentsmaturityDetails Leases - Operating lease,future rental payments, maturity (Details) Details 68 false false R69.htm 2455428 - Disclosure - Leases - Weighted average remaining lease term and weighted average discount rate (Details) Sheet http://www.greenhill.com/role/LeasesWeightedaverageremainingleasetermandweightedaveragediscountrateDetails Leases - Weighted average remaining lease term and weighted average discount rate (Details) Details 69 false false R70.htm 2456429 - Disclosure - Leases - Aggregate Minimum Future Rental Payments (Details) Sheet http://www.greenhill.com/role/LeasesAggregateMinimumFutureRentalPaymentsDetails Leases - Aggregate Minimum Future Rental Payments (Details) Details 70 false false R71.htm 2458430 - Disclosure - Regulatory - Additional Information (Detail) Sheet http://www.greenhill.com/role/RegulatoryAdditionalInformationDetail Regulatory - Additional Information (Detail) Details 71 false false R72.htm 2461431 - Disclosure - Business Information - Additional Information (Details) Sheet http://www.greenhill.com/role/BusinessInformationAdditionalInformationDetails Business Information - Additional Information (Details) Details 72 false false R73.htm 2462432 - Disclosure - Business Information - Information by Geographic Region, After Elimination of All Significant Inter-company Accounts and Transactions (Details) Sheet http://www.greenhill.com/role/BusinessInformationInformationbyGeographicRegionAfterEliminationofAllSignificantIntercompanyAccountsandTransactionsDetails Business Information - Information by Geographic Region, After Elimination of All Significant Inter-company Accounts and Transactions (Details) Details 73 false false R74.htm 2464433 - Disclosure - Subsequent Events (Details) Sheet http://www.greenhill.com/role/SubsequentEventsDetails Subsequent Events (Details) Details http://www.greenhill.com/role/SubsequentEvents 74 false false R75.htm 2467434 - Disclosure - Supplemental Financial Information Quarterly Results (unaudited) - Schedule of Unaudited Quarterly Results (Details) Sheet http://www.greenhill.com/role/SupplementalFinancialInformationQuarterlyResultsunauditedScheduleofUnauditedQuarterlyResultsDetails Supplemental Financial Information Quarterly Results (unaudited) - Schedule of Unaudited Quarterly Results (Details) Details http://www.greenhill.com/role/SupplementalFinancialInformationQuarterlyResultsunauditedTables 75 false false All Reports Book All Reports ghl-20191231.htm ex311-ghlx12312019.htm ex312-ghlx12312019.htm ex321-ghlx12312019.htm ex322-ghlx12312019.htm ex42-descriptionofgree.htm exhibit211-ghl12312019.htm exhibit231-ghl12312019.htm ghl-20191231.xsd ghl-20191231_cal.xml ghl-20191231_def.xml ghl-20191231_lab.xml ghl-20191231_pre.xml ghl-20191231_g1.jpg http://fasb.org/us-gaap/2019-01-31 http://xbrl.sec.gov/dei/2019-01-31 http://xbrl.sec.gov/country/2017-01-31 http://fasb.org/srt/2019-01-31 true true