3.25.4 html 102 323 1 false 28 0 false 5 false false R1.htm 995200090 - Document - Document and Entity Information Sheet http://www.uslm.com/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 995200100 - Statement - Consolidated Balance Sheets Sheet http://www.uslm.com/role/StatementConsolidatedBalanceSheets Consolidated Balance Sheets Statements 2 false false R3.htm 995200105 - Statement - Consolidated Balance Sheets (Parenthetical) Sheet http://www.uslm.com/role/StatementConsolidatedBalanceSheetsParenthetical Consolidated Balance Sheets (Parenthetical) Statements 3 false false R4.htm 995200200 - Statement - Consolidated Statements of Income Sheet http://www.uslm.com/role/StatementConsolidatedStatementsOfIncome Consolidated Statements of Income Statements 4 false false R5.htm 995200300 - Statement - Consolidated Statements of Stockholders' Equity Sheet http://www.uslm.com/role/StatementConsolidatedStatementsOfStockholdersEquity Consolidated Statements of Stockholders' Equity Statements 5 false false R6.htm 995200400 - Statement - Consolidated Statements of Cash Flows Sheet http://www.uslm.com/role/StatementConsolidatedStatementsOfCashFlows Consolidated Statements of Cash Flows Statements 6 false false R7.htm 995210101 - Disclosure - Summary of Significant Accounting Policies Sheet http://www.uslm.com/role/DisclosureSummaryOfSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 7 false false R8.htm 995210201 - Disclosure - Banking Facilities and Debt Sheet http://www.uslm.com/role/DisclosureBankingFacilitiesAndDebt Banking Facilities and Debt Notes 8 false false R9.htm 995210301 - Disclosure - Leases Sheet http://www.uslm.com/role/DisclosureLeases Leases Notes 9 false false R10.htm 995210401 - Disclosure - Income Taxes Sheet http://www.uslm.com/role/DisclosureIncomeTaxes Income Taxes Notes 10 false false R11.htm 995210501 - Disclosure - Employee Retirement Plans Sheet http://www.uslm.com/role/DisclosureEmployeeRetirementPlans Employee Retirement Plans Notes 11 false false R12.htm 995210601 - Disclosure - Stock-Based Compensation Sheet http://www.uslm.com/role/DisclosureStockBasedCompensation Stock-Based Compensation Notes 12 false false R13.htm 995210701 - Disclosure - Share Repurchases Sheet http://www.uslm.com/role/DisclosureShareRepurchases Share Repurchases Notes 13 false false R14.htm 995210801 - Disclosure - Commitments and Contingencies Sheet http://www.uslm.com/role/DisclosureCommitmentsAndContingencies Commitments and Contingencies Notes 14 false false R15.htm 995210901 - Disclosure - Reportable Segment Sheet http://www.uslm.com/role/DisclosureReportableSegment Reportable Segment Notes 15 false false R16.htm 995211001 - Disclosure - Subsequent Events Sheet http://www.uslm.com/role/DisclosureSubsequentEvents Subsequent Events Notes 16 false false R17.htm 995410 - Disclosure - Pay vs Performance Disclosure Sheet http://xbrl.sec.gov/ecd/role/PvpDisclosure Pay vs Performance Disclosure Notes 17 false false R18.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 18 false false R19.htm 995447 - Disclosure - Insider Trading Policies and Procedures Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc Insider Trading Policies and Procedures Notes 19 false false R20.htm 995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure Sheet http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure Cybersecurity Risk Management and Strategy Disclosure Notes 20 false false R21.htm 99920102 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://www.uslm.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://www.uslm.com/role/DisclosureSummaryOfSignificantAccountingPolicies 21 false false R22.htm 99930103 - Disclosure - Summary of Significant Accounting Policies (Tables) Sheet http://www.uslm.com/role/DisclosureSummaryOfSignificantAccountingPoliciesTables Summary of Significant Accounting Policies (Tables) Tables http://www.uslm.com/role/DisclosureSummaryOfSignificantAccountingPolicies 22 false false R23.htm 99930303 - Disclosure - Leases (Tables) Sheet http://www.uslm.com/role/DisclosureLeasesTables Leases (Tables) Tables http://www.uslm.com/role/DisclosureLeases 23 false false R24.htm 99930403 - Disclosure - Income Taxes (Tables) Sheet http://www.uslm.com/role/DisclosureIncomeTaxesTables Income Taxes (Tables) Tables http://www.uslm.com/role/DisclosureIncomeTaxes 24 false false R25.htm 99930603 - Disclosure - Stock-Based Compensation (Tables) Sheet http://www.uslm.com/role/DisclosureStockBasedCompensationTables Stock-Based Compensation (Tables) Tables http://www.uslm.com/role/DisclosureStockBasedCompensation 25 false false R26.htm 99930903 - Disclosure - Reportable Segment (Tables) Sheet http://www.uslm.com/role/DisclosureReportableSegmentTables Reportable Segment (Tables) Tables http://www.uslm.com/role/DisclosureReportableSegment 26 false false R27.htm 99940101 - Disclosure - Summary of Significant Accounting Policies - Additional Disclosures (Details) Sheet http://www.uslm.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalDisclosuresDetails Summary of Significant Accounting Policies - Additional Disclosures (Details) Details 27 false false R28.htm 99940102 - Disclosure - Summary of Significant Accounting Policies - PP&E, ARO and Other (Details) Sheet http://www.uslm.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPpEAroAndOtherDetails Summary of Significant Accounting Policies - PP&E, ARO and Other (Details) Details 28 false false R29.htm 99940103 - Disclosure - Summary of Significant Accounting Policies - Income Per Share (Details) Sheet http://www.uslm.com/role/DisclosureSummaryOfSignificantAccountingPoliciesIncomePerShareDetails Summary of Significant Accounting Policies - Income Per Share (Details) Details 29 false false R30.htm 99940201 - Disclosure - Banking Facilities and Debt (Details) Sheet http://www.uslm.com/role/DisclosureBankingFacilitiesAndDebtDetails Banking Facilities and Debt (Details) Details http://www.uslm.com/role/DisclosureBankingFacilitiesAndDebt 30 false false R31.htm 99940301 - Disclosure - Leases - Costs Disclosure (Details) Sheet http://www.uslm.com/role/DisclosureLeasesCostsDisclosureDetails Leases - Costs Disclosure (Details) Details 31 false false R32.htm 99940302 - Disclosure - Leases - Maturity (Details) Sheet http://www.uslm.com/role/DisclosureLeasesMaturityDetails Leases - Maturity (Details) Details 32 false false R33.htm 99940303 - Disclosure - Leases - Supplemental Cash Flow Information (Details) Sheet http://www.uslm.com/role/DisclosureLeasesSupplementalCashFlowInformationDetails Leases - Supplemental Cash Flow Information (Details) Details 33 false false R34.htm 99940401 - Disclosure - Income Taxes (Details) Sheet http://www.uslm.com/role/DisclosureIncomeTaxesDetails Income Taxes (Details) Details http://www.uslm.com/role/DisclosureIncomeTaxesTables 34 false false R35.htm 99940501 - Disclosure - Employee Retirement Plans (Details) Sheet http://www.uslm.com/role/DisclosureEmployeeRetirementPlansDetails Employee Retirement Plans (Details) Details http://www.uslm.com/role/DisclosureEmployeeRetirementPlans 35 false false R36.htm 99940601 - Disclosure - Stock-Based Compensation (Details) Sheet http://www.uslm.com/role/DisclosureStockBasedCompensationDetails Stock-Based Compensation (Details) Details http://www.uslm.com/role/DisclosureStockBasedCompensationTables 36 false false R37.htm 99940701 - Disclosure - Share Repurchases (Details) Sheet http://www.uslm.com/role/DisclosureShareRepurchasesDetails Share Repurchases (Details) Details http://www.uslm.com/role/DisclosureShareRepurchases 37 false false R38.htm 99940801 - Disclosure - Commitments and Contingencies (Details) Sheet http://www.uslm.com/role/DisclosureCommitmentsAndContingenciesDetails Commitments and Contingencies (Details) Details http://www.uslm.com/role/DisclosureCommitmentsAndContingencies 38 false false R39.htm 99940901 - Disclosure - Reportable Segment (Details) Sheet http://www.uslm.com/role/DisclosureReportableSegmentDetails Reportable Segment (Details) Details http://www.uslm.com/role/DisclosureReportableSegmentTables 39 false false R40.htm 99941001 - Disclosure - Subsequent Event (Details) Sheet http://www.uslm.com/role/DisclosureSubsequentEventDetails Subsequent Event (Details) Details http://www.uslm.com/role/DisclosureSubsequentEvents 40 false false All Reports Book All Reports uslm-20251231.xsd uslm-20251231_cal.xml uslm-20251231_def.xml uslm-20251231_lab.xml uslm-20251231_pre.xml uslm-20251231x10k.htm uslm-20251231x10k001.jpg uslm-20251231x10k002.jpg uslm-20251231x10k003.jpg uslm-20251231x10k004.jpg uslm-20251231x10k005.jpg uslm-20251231x10k006.jpg http://fasb.org/us-gaap/2025 http://xbrl.sec.gov/cyd/2025 http://xbrl.sec.gov/dei/2025 http://xbrl.sec.gov/ecd/2025 true true