XML 20 R57.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Long-Term Debt (Details Textual) | 3 Months Ended |  |  | 3 Months Ended |  |  |  |  |  | 3 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 31, 2015 USD ($) | Mar. 31, 2014 USD ($) | Dec. 31, 2014 USD ($) | Mar. 31, 2015 Capital Lease Obligations [Member] | Mar. 31, 2015 5.00% Senior Note [Member] USD ($) | Sep. 30, 2014 5.00% Senior Note [Member] USD ($) | Dec. 31, 2014 5.00% Senior Note [Member] USD ($) | Jun. 30, 2014 5.00% Senior Note [Member] USD ($) | Mar. 31, 2015 Other Real Estate Related Long Term Debt [Member] USD ($) | Dec. 31, 2014 Other Real Estate Related Long Term Debt [Member] USD ($) | Mar. 31, 2015 2.25% Convertible Senior Notes due 2036 [Member] | Mar. 31, 2015 Two Point Two Five Percent Warrants [Member] | Mar. 31, 2015 Three Point Zero Zero Percent Notes [Member] | Mar. 31, 2015 3.00% Warrants [Member] | Mar. 31, 2015 Real Estate Related Debt [Member] USD ($) | Mar. 31, 2015 Real Estate Related Debt [Member] Minimum [Member] | Mar. 31, 2015 Real Estate Related Debt [Member] Maximum [Member] | Mar. 31, 2015 Real Estate Related Debt [Member] Toyota Motor Credit Corporation [Member] USD ($) | Mar. 31, 2015 Real Estate Related Debt [Member] Mercedes-Benz Financial Services [Member] USD ($) | Mar. 31, 2015 Real Estate Related Debt [Member] BMW Financial Services [Member] USD ($) | Mar. 31, 2015 Real Estate Related Debt [Member] Ford Motor Credit Company [Member] USD ($) | Mar. 31, 2015 Foreign Note [Member] USD ($) | Mar. 31, 2015 Brazilian third party financial institution [Member] BRL | Mar. 31, 2015 Third-party financial institution [Member] USD ($) | Mar. 31, 2015 Third-party financial institution [Member] Ford Motor Credit Company [Member] USD ($) | Mar. 31, 2015 Real Estate Credit Facility [Member] USD ($) | Mar. 31, 2015 Real Estate Credit Facility [Member] Minimum [Member] | Mar. 31, 2015 Real Estate Credit Facility [Member] Maximum [Member] | Mar. 31, 2015 London Interbank Offered Rate (LIBOR) [Member] Real Estate Credit Facility [Member] | Mar. 31, 2015 Federal Funds Rate [Member] Real Estate Credit Facility [Member] | Mar. 31, 2015 Fixed interest rate debt [Member] Other Real Estate Related Long Term Debt [Member] USD ($) | Dec. 31, 2014 Fixed interest rate debt [Member] Other Real Estate Related Long Term Debt [Member] USD ($)
Long-term Debt (Textual) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Periodic Payment, Principal |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 500,000 us-gaap_DebtInstrumentPeriodicPaymentPrincipal / us-gaap_LineOfCreditFacilityAxis = gpi_ToyotaMotorCreditCorporationMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of Long-term Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 300,000 us-gaap_RepaymentsOfLongTermDebt / us-gaap_LineOfCreditFacilityAxis = gpi_MercedesBenzFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | 1,100,000 us-gaap_RepaymentsOfLongTermDebt / us-gaap_LineOfCreditFacilityAxis = gpi_BmwFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | 400,000 us-gaap_RepaymentsOfLongTermDebt / us-gaap_LineOfCreditFacilityAxis = gpi_FordMotorCreditCompanyMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | 500,000 us-gaap_RepaymentsOfLongTermDebt / us-gaap_LongtermDebtTypeAxis = gpi_ForeignNoteMember |  | 1,500,000 us-gaap_RepaymentsOfLongTermDebt / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember |  |  |  |  |  |  |  |
Allocated Underwriter Fees Net Of Taxes |  |  |  |  | 10,400,000 gpi_AllocatedUnderwriterFeesNetOfTaxes / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, Weighted Average Interest Rate |  |  |  | 9.60%us-gaap_DebtWeightedAverageInterestRate / us-gaap_LongtermDebtTypeAxis = us-gaap_CapitalLeaseObligationsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization period of underwriters fees and debt issuance costs | 8 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums |  |  |  |  | 9,600,000 us-gaap_UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term Debt, Percentage Bearing Fixed Interest, Amount |  |  |  |  |  |  |  |  | 156,600,000 us-gaap_LongtermDebtPercentageBearingFixedInterestAmount / us-gaap_LongtermDebtTypeAxis = gpi_OtherRealEstateRelatedLongTermDebtMember | 158,100,000 us-gaap_LongtermDebtPercentageBearingFixedInterestAmount / us-gaap_LongtermDebtTypeAxis = gpi_OtherRealEstateRelatedLongTermDebtMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term Debt, Fair Value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 181,100,000 us-gaap_LongTermDebtFairValue / gpi_DebtinterestratetypeAxis = gpi_FixedinterestratedebtMember / us-gaap_LongtermDebtTypeAxis = gpi_OtherRealEstateRelatedLongTermDebtMember | 186,400,000 us-gaap_LongTermDebtFairValue / gpi_DebtinterestratetypeAxis = gpi_FixedinterestratedebtMember / us-gaap_LongtermDebtTypeAxis = gpi_OtherRealEstateRelatedLongTermDebtMember
Debt interest rate |  |  |  |  | 5.00%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  | 2.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis = gpi_A2.25ConvertibleNotesMember | 2.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis = gpi_TwoPointTwoFivePercentWarrantsMember | 3.00%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis = gpi_ThreePointZeroZeroPercentNotesMember | 3.00%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis = us-gaap_WarrantMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity date of of notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Nov. 01, 2021 |  | Oct. 01, 2021 |  | Sep. 01, 2034 |  |  |  |  |  |  |  |  |  |
Note agreement with a third party financial institution |  |  |  |  | 550,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  | 550,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember | 350,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Additional borrowings of long term debt |  |  |  |  |  | 200,000,000 gpi_Additionalborrowingsoflongtermdebt / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Additional borrowings discount from face value |  |  |  |  | 1.50%gpi_Additionalborrowingsdiscountfromfacevalue / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term loans provided under credit facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 127,200,000 gpi_TermLoansUnderRealEstateCreditFacility / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember |  | 74,100,000 gpi_TermLoansUnderRealEstateCreditFacility / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Capitalization Of Debt Issuance Costs |  |  |  |  | 2,400,000 gpi_CapitalizationOfDebtIssuanceCosts / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  | 1,300,000 gpi_CapitalizationOfDebtIssuanceCosts / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember |  |  |  |  |  |  |  |  |  |  | 1,100,000 gpi_CapitalizationOfDebtIssuanceCosts / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Amount available to be expanded |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 99,100,000 gpi_MaximumAmountOfTermLoanToBeExpandUnderRealEstateCreditFacility / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Unamortized debt issuance cost |  |  |  |  | 2,100,000 us-gaap_UnamortizedDebtIssuanceExpense / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  | 400,000 us-gaap_UnamortizedDebtIssuanceExpense / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember |  |  |  |  |  |  |  |  |  |  | 300,000 us-gaap_UnamortizedDebtIssuanceExpense / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Interest rate under condition second |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.95%gpi_InterestRateUnderConditionSecond / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Interest rate under sub-condition three of condition second |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.05%gpi_InterestRateUnderSubConditionThreeOfConditionSecond / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |
Percentage of principal payments to make its quarterly payment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.25%gpi_PercentageOfQuarterlyPrincipalPaymentsOfOutstandingPrincipal / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Ending date of installments to be repaid |  |  |  |  | Jun. 01, 2022 |  |  |  |  |  |  |  |  |  |  |  |  |  | Jan. 01, 2031 |  | Dec. 01, 2024 |  | Feb. 01, 2017 | Nov. 01, 2022 |  |  | Dec. 29, 2015 | Feb. 27, 2017 |  |  |  |
Redemption price percentage of principal outstanding and accrued unpaid interest |  |  |  |  | 105.00%gpi_Redemptionpricepercentageofprincipaloutstandingandaccruedunpaidinterest / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Redemption price percentage of principal redeemed |  |  |  |  | 100.00%gpi_Redemptionpricepercentageofprincipalredeemed / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Borrowings under amended and restated mortgage facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 gpi_BorrowingsUnderAmendedAndRestatedMortgageFacility / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Principal payments on outstanding borrowings |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 800,000 us-gaap_LineOfCreditFacilityPeriodicPaymentPrincipal / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Current maturities of long-term debt | 69,275,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent |  | 72,630,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,100,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent / us-gaap_LineOfCreditFacilityAxis = gpi_ToyotaMotorCreditCorporationMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | 1,100,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent / us-gaap_LineOfCreditFacilityAxis = gpi_MercedesBenzFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | 4,500,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent / us-gaap_LineOfCreditFacilityAxis = gpi_BmwFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember |  | 4,500,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent / us-gaap_LongtermDebtTypeAxis = gpi_ForeignNoteMember |  | 6,600,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember | 1,500,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent / us-gaap_LineOfCreditFacilityAxis = gpi_FordMotorCreditCompanyMember / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember | 30,900,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Number of manufacturer-affiliated finance partners | 4 gpi_Numberofmanufactureraffiliatedfinancepartners |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest on real estate notes, minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.00%us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMinimum / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest on real estate notes, maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMaximum / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 20 years | 20 years | 15 years | 20 years |  |  |  |  |  |  |  |  |  |  |
Variable Interest Rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember / us-gaap_RangeAxis = us-gaap_MinimumMember | 2.55%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |  | 2.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  | 0.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember / us-gaap_VariableRateAxis = gpi_FederalFundsRateMember |  |
Total borrowings |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 49,400,000 us-gaap_LongTermDebt / us-gaap_LineOfCreditFacilityAxis = gpi_ToyotaMotorCreditCorporationMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | 27,100,000 us-gaap_LongTermDebt / us-gaap_LineOfCreditFacilityAxis = gpi_MercedesBenzFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | 64,800,000 us-gaap_LongTermDebt / us-gaap_LineOfCreditFacilityAxis = gpi_BmwFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember |  | 60,400,000 us-gaap_LongTermDebt / us-gaap_LongtermDebtTypeAxis = gpi_ForeignNoteMember | 38,000,000 us-gaap_LongTermDebt / us-gaap_LongtermDebtTypeAxis = gpi_BrazilianthirdpartyfinancialinstitutionMember | 113,600,000 us-gaap_LongTermDebt / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember | 34,700,000 us-gaap_LongTermDebt / us-gaap_LineOfCreditFacilityAxis = gpi_FordMotorCreditCompanyMember / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember | 57,200,000 us-gaap_LongTermDebt / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateCreditFacilityMember |  |  |  |  |  |
Convertible Debt, Fair Value Disclosures |  |  |  |  | 551,400,000 us-gaap_ConvertibleDebtFairValueDisclosures / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  | 534,900,000 us-gaap_ConvertibleDebtFairValueDisclosures / us-gaap_LongtermDebtTypeAxis = gpi_A5.00SeniorNoteMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of loans as per loan agreements |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8 us-gaap_MortgageLoansOnRealEstateNumberOfLoans / us-gaap_LineOfCreditFacilityAxis = gpi_ToyotaMotorCreditCorporationMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | 2 us-gaap_MortgageLoansOnRealEstateNumberOfLoans / us-gaap_LineOfCreditFacilityAxis = gpi_MercedesBenzFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | 14 us-gaap_MortgageLoansOnRealEstateNumberOfLoans / us-gaap_LineOfCreditFacilityAxis = gpi_BmwFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember |  |  |  | 19 us-gaap_MortgageLoansOnRealEstateNumberOfLoans / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember | 4 us-gaap_MortgageLoansOnRealEstateNumberOfLoans / us-gaap_LineOfCreditFacilityAxis = gpi_FordMotorCreditCompanyMember / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember |  |  |  |  |  |  |
Borrowings Of Long Term Debt Related To Real Estate Loans | $ 17,600,000 gpi_BorrowingsOfLongTermDebtRelatedToRealEstateLoans | $ 13,855,000 gpi_BorrowingsOfLongTermDebtRelatedToRealEstateLoans |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 gpi_BorrowingsOfLongTermDebtRelatedToRealEstateLoans / us-gaap_LineOfCreditFacilityAxis = gpi_ToyotaMotorCreditCorporationMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | $ 0 gpi_BorrowingsOfLongTermDebtRelatedToRealEstateLoans / us-gaap_LineOfCreditFacilityAxis = gpi_MercedesBenzFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember | $ 0 gpi_BorrowingsOfLongTermDebtRelatedToRealEstateLoans / us-gaap_LineOfCreditFacilityAxis = gpi_BmwFinancialServicesMember / us-gaap_LongtermDebtTypeAxis = gpi_RealEstateRelatedDebtMember |  | $ 17,400,000 gpi_BorrowingsOfLongTermDebtRelatedToRealEstateLoans / us-gaap_LongtermDebtTypeAxis = gpi_ForeignNoteMember |  | $ 0 gpi_BorrowingsOfLongTermDebtRelatedToRealEstateLoans / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember | $ 0 gpi_BorrowingsOfLongTermDebtRelatedToRealEstateLoans / us-gaap_LineOfCreditFacilityAxis = gpi_FordMotorCreditCompanyMember / us-gaap_LongtermDebtTypeAxis = gpi_ThirdPartyFinancialInstitutionMember |  |  |  |  |  |  |
Lease Expiration Date | Jun. 01, 2034 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Additional borrowings discount from face value + References No definition available. + Details
Name: | gpi_Additionalborrowingsdiscountfromfacevalue
Namespace Prefix: | gpi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Additional borrowings of long term debt + References No definition available. + Details
Name: | gpi_Additionalborrowingsoflongtermdebt
Namespace Prefix: | gpi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Allocated underwriter fees, net of taxes. + References No definition available. + Details
Name: | gpi_AllocatedUnderwriterFeesNetOfTaxes
Namespace Prefix: | gpi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortization period of underwriters fees and debt issuance costs + References No definition available. + Details
Name: | gpi_Amortizationperiodofunderwritersfeesanddebtissuancecosts
Namespace Prefix: | gpi_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amortization schedule of loan agreement. + References No definition available. + Details
Name: | gpi_AmortizationScheduleOfLoanAgreement
Namespace Prefix: | gpi_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Borrowings of long term debt related to real estate loans. + References No definition available. + Details
Name: | gpi_BorrowingsOfLongTermDebtRelatedToRealEstateLoans
Namespace Prefix: | gpi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Borrowings under amended and restated mortgage facility. + References No definition available. + Details
Name: | gpi_BorrowingsUnderAmendedAndRestatedMortgageFacility
Namespace Prefix: | gpi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Capitalization of debt issuance costs. + References No definition available. + Details
Name: | gpi_CapitalizationOfDebtIssuanceCosts
Namespace Prefix: | gpi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Interest rate under condition second. + References No definition available. + Details
Name: | gpi_InterestRateUnderConditionSecond
Namespace Prefix: | gpi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest rate under sub-condition three of condition second. + References No definition available. + Details
Name: | gpi_InterestRateUnderSubConditionThreeOfConditionSecond
Namespace Prefix: | gpi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum amount of term loan to be expand under real estate credit facility. + References No definition available. + Details
Name: | gpi_MaximumAmountOfTermLoanToBeExpandUnderRealEstateCreditFacility
Namespace Prefix: | gpi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of manufacture-affiliates with mortgaged loans + References No definition available. + Details
Name: | gpi_Numberofmanufactureraffiliatedfinancepartners
Namespace Prefix: | gpi_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of quarterly principal payments of outstanding principal. + References No definition available. + Details
Name: | gpi_PercentageOfQuarterlyPrincipalPaymentsOfOutstandingPrincipal
Namespace Prefix: | gpi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Redemption price percentage of principal outstanding and accrued unpaid interest + References No definition available. + Details
Name: | gpi_Redemptionpricepercentageofprincipaloutstandingandaccruedunpaidinterest
Namespace Prefix: | gpi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Redemption price percentage of principal redeemed + References No definition available. + Details
Name: | gpi_Redemptionpricepercentageofprincipalredeemed
Namespace Prefix: | gpi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Term loans under real estate credit facility. + References No definition available. + Details
Name: | gpi_TermLoansUnderRealEstateCreditFacility
Namespace Prefix: | gpi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Convertible Security -URI http://asc.fasb.org/extlink&oid=6509036 + Details
Name: | us-gaap_ConvertibleDebtFairValueDisclosures
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Maximum contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMaximum
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMinimum
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDateRangeEnd1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of the required periodic payments applied to principal. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentPeriodicPaymentPrincipal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Weighted average interest rate of debt outstanding. + References No definition available. + Details
Name: | us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Date which lease or group of leases is set to expire, in CCYY-MM-DD format. + References No definition available. + Details
Name: | us-gaap_LeaseExpirationDate1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of the required periodic payment applied to principal. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
Name: | us-gaap_LineOfCreditFacilityPeriodicPaymentPrincipal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20, 22 -Article 5 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LongTermDebtByMaturityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. + References No definition available. + Details
Name: | us-gaap_LongTermDebtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate. + References No definition available. + Details
Name: | us-gaap_LongtermDebtPercentageBearingFixedInterestAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Indicates the number of mortgages under each classification. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 10 -Section S99 -Paragraph 6 -Subparagraph (SX 210.5-04.(c) Schedule IV) -URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 948 -SubTopic 310 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-29.3) -URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule IV -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 29 -Paragraph 3 -Article 12 + Details
Name: | us-gaap_MortgageLoansOnRealEstateNumberOfLoans
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 + Details
Name: | us-gaap_RepaymentsOfLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_UnamortizedDebtIssuanceExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533 + Details
Name: | us-gaap_UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant