XML 22 R89.htm IDEA: XBRL DOCUMENT v2.4.1.9
Condensed Consolidated Financial Information Condensed Consolidated Balance Sheet (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Cash and Cash Equivalents, at Carrying Value $ 40,975us-gaap_CashAndCashEquivalentsAtCarryingValue $ 20,215us-gaap_CashAndCashEquivalentsAtCarryingValue $ 4,650us-gaap_CashAndCashEquivalentsAtCarryingValue $ 14,895us-gaap_CashAndCashEquivalentsAtCarryingValue
Contracts In Transit And Vehicle Receivables Net 237,448gpi_ContractsInTransitAndVehicleReceivablesNet 225,156gpi_ContractsInTransitAndVehicleReceivablesNet    
Accounts, Notes, Loans and Financing Receivable, Net, Current 151,330us-gaap_AccountsNotesAndLoansReceivableNetCurrent 135,058us-gaap_AccountsNotesAndLoansReceivableNetCurrent    
Intercompany accounts receivable current 0gpi_Intercompanyaccountsreceivablecurrent 0gpi_Intercompanyaccountsreceivablecurrent    
Inventory, Net 1,556,705us-gaap_InventoryNet 1,542,318us-gaap_InventoryNet    
Deferred Tax Assets, Net, Current 11,062us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent 21,150us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent    
Prepaid Expense and Other Assets, Current 37,699us-gaap_PrepaidExpenseAndOtherAssetsCurrent 24,041us-gaap_PrepaidExpenseAndOtherAssetsCurrent    
Total current assets 2,035,219us-gaap_AssetsCurrent 1,967,938us-gaap_AssetsCurrent    
Property, Plant and Equipment, Net 950,388us-gaap_PropertyPlantAndEquipmentNet 796,356us-gaap_PropertyPlantAndEquipmentNet    
Goodwill 830,377us-gaap_Goodwill 737,303us-gaap_Goodwill 582,384us-gaap_Goodwill  
Indefinite-Lived Franchise Rights 303,947us-gaap_IndefiniteLivedFranchiseRights 301,505us-gaap_IndefiniteLivedFranchiseRights    
Investment in Subsidiaries 0gpi_InvestmentinSubsidiaries 0gpi_InvestmentinSubsidiaries    
Other Assets, Noncurrent 21,561us-gaap_OtherAssetsNoncurrent 16,376us-gaap_OtherAssetsNoncurrent    
Total assets 4,141,492us-gaap_Assets 3,819,478us-gaap_Assets    
Floorplan Notes Payable Credit Facility Gross 1,143,246gpi_FloorplanNotesPayableCreditFacilityGross 1,143,104gpi_FloorplanNotesPayableCreditFacilityGross    
Floorplan Offset (39,616)gpi_FloorplanOffset (56,198)gpi_FloorplanOffset    
Floorplan Notes Payable Manufacturer Affiliates 307,656gpi_FloorplanNotesPayableManufacturerAffiliates 346,572gpi_FloorplanNotesPayableManufacturerAffiliates    
FMCC Offset (22,500)gpi_FMCCOffset 0gpi_FMCCOffset    
Long-term Debt and Capital Lease Obligations, Current 72,630us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent 36,225us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent    
Accounts Payable, Current 288,320us-gaap_AccountsPayableCurrent 254,930us-gaap_AccountsPayableCurrent    
Intercompany accounts payable current 0gpi_Intercompanyaccountspayablecurrent 0gpi_Intercompanyaccountspayablecurrent    
Accrued Liabilities, Current 172,463us-gaap_AccruedLiabilitiesCurrent 140,543us-gaap_AccruedLiabilitiesCurrent    
Total current liabilities 1,922,199us-gaap_LiabilitiesCurrent 1,865,176us-gaap_LiabilitiesCurrent    
Long-term Debt and Capital Lease Obligations 1,008,837us-gaap_LongTermDebtAndCapitalLeaseObligations 663,689us-gaap_LongTermDebtAndCapitalLeaseObligations    
Derivative Liability, Noncurrent 25,311us-gaap_DerivativeLiabilitiesNoncurrent 26,078us-gaap_DerivativeLiabilitiesNoncurrent    
Other Liabilities, Noncurrent 207,135gpi_Deferredincometaxesandotherliabilities 200,266gpi_Deferredincometaxesandotherliabilities    
Temporary Equity, Carrying Amount, Attributable to Parent 0us-gaap_TemporaryEquityCarryingAmountAttributableToParent 29,094us-gaap_TemporaryEquityCarryingAmountAttributableToParent    
Stockholders' Equity Attributable to Parent 978,010us-gaap_StockholdersEquity 1,035,175us-gaap_StockholdersEquity 860,284us-gaap_StockholdersEquity 807,100us-gaap_StockholdersEquity
Intercompany note receivable 0gpi_Intercompanynotereceivable 0gpi_Intercompanynotereceivable    
Total liabilities and stockholders' equity 4,141,492us-gaap_LiabilitiesAndStockholdersEquity 3,819,478us-gaap_LiabilitiesAndStockholdersEquity    
Parent Company [Member]        
Cash and Cash Equivalents, at Carrying Value 0us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
Contracts In Transit And Vehicle Receivables Net 0gpi_ContractsInTransitAndVehicleReceivablesNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0gpi_ContractsInTransitAndVehicleReceivablesNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Accounts, Notes, Loans and Financing Receivable, Net, Current 0us-gaap_AccountsNotesAndLoansReceivableNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_AccountsNotesAndLoansReceivableNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Intercompany accounts receivable current 0gpi_Intercompanyaccountsreceivablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0gpi_Intercompanyaccountsreceivablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Inventory, Net 0us-gaap_InventoryNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_InventoryNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Deferred Tax Assets, Net, Current 196us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
2,279us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Prepaid Expense and Other Assets, Current 590us-gaap_PrepaidExpenseAndOtherAssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
619us-gaap_PrepaidExpenseAndOtherAssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Total current assets 786us-gaap_AssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
2,898us-gaap_AssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Property, Plant and Equipment, Net 0us-gaap_PropertyPlantAndEquipmentNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_PropertyPlantAndEquipmentNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Goodwill 0us-gaap_Goodwill
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_Goodwill
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Indefinite-Lived Franchise Rights 0us-gaap_IndefiniteLivedFranchiseRights
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_IndefiniteLivedFranchiseRights
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Investment in Subsidiaries 1,964,442gpi_InvestmentinSubsidiaries
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
1,710,185gpi_InvestmentinSubsidiaries
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Other Assets, Noncurrent 0us-gaap_OtherAssetsNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_OtherAssetsNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Total assets 1,965,228us-gaap_Assets
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
1,713,083us-gaap_Assets
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Floorplan Notes Payable Credit Facility Gross 0gpi_FloorplanNotesPayableCreditFacilityGross
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0gpi_FloorplanNotesPayableCreditFacilityGross
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Floorplan Offset 0gpi_FloorplanOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0gpi_FloorplanOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Floorplan Notes Payable Manufacturer Affiliates 0gpi_FloorplanNotesPayableManufacturerAffiliates
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0gpi_FloorplanNotesPayableManufacturerAffiliates
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
FMCC Offset 0gpi_FMCCOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
     
Long-term Debt and Capital Lease Obligations, Current 0us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Accounts Payable, Current 0us-gaap_AccountsPayableCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_AccountsPayableCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Intercompany accounts payable current 295,421gpi_Intercompanyaccountspayablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
292,498gpi_Intercompanyaccountspayablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Accrued Liabilities, Current 0us-gaap_AccruedLiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_AccruedLiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Total current liabilities 295,421us-gaap_LiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
292,498us-gaap_LiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Long-term Debt and Capital Lease Obligations 609,812us-gaap_LongTermDebtAndCapitalLeaseObligations
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
304,637us-gaap_LongTermDebtAndCapitalLeaseObligations
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Derivative Liability, Noncurrent 0us-gaap_DerivativeLiabilitiesNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0us-gaap_DerivativeLiabilitiesNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Other Liabilities, Noncurrent 0gpi_Deferredincometaxesandotherliabilities
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0gpi_Deferredincometaxesandotherliabilities
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Temporary Equity, Carrying Amount, Attributable to Parent   29,094us-gaap_TemporaryEquityCarryingAmountAttributableToParent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Stockholders' Equity Attributable to Parent 1,059,995us-gaap_StockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
1,086,854us-gaap_StockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Intercompany note receivable 0gpi_Intercompanynotereceivable
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
0gpi_Intercompanynotereceivable
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Stockholders' Equity Attributable to Parent Excluding Intercompany Receivables 1,059,995gpi_StockholdersEquityAttributabletoParentExcludingIntercompanyReceivables
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
     
Total liabilities and stockholders' equity 1,965,228us-gaap_LiabilitiesAndStockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
1,713,083us-gaap_LiabilitiesAndStockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ParentCompanyMember
   
Guarantor Subsidiaries [Member]        
Cash and Cash Equivalents, at Carrying Value 25,379us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
4,306us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
4,341us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
6,862us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
Contracts In Transit And Vehicle Receivables Net 218,361gpi_ContractsInTransitAndVehicleReceivablesNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
217,462gpi_ContractsInTransitAndVehicleReceivablesNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Accounts, Notes, Loans and Financing Receivable, Net, Current 117,427us-gaap_AccountsNotesAndLoansReceivableNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
104,732us-gaap_AccountsNotesAndLoansReceivableNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Intercompany accounts receivable current 276,217gpi_Intercompanyaccountsreceivablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
212,592gpi_Intercompanyaccountsreceivablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Inventory, Net 1,342,022us-gaap_InventoryNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
1,339,062us-gaap_InventoryNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Deferred Tax Assets, Net, Current 10,866us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
18,871us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Prepaid Expense and Other Assets, Current 22,039us-gaap_PrepaidExpenseAndOtherAssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
9,974us-gaap_PrepaidExpenseAndOtherAssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Total current assets 2,012,311us-gaap_AssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
1,906,999us-gaap_AssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Property, Plant and Equipment, Net 839,063us-gaap_PropertyPlantAndEquipmentNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
715,586us-gaap_PropertyPlantAndEquipmentNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Goodwill 700,642us-gaap_Goodwill
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
612,469us-gaap_Goodwill
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Indefinite-Lived Franchise Rights 257,502us-gaap_IndefiniteLivedFranchiseRights
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
216,412us-gaap_IndefiniteLivedFranchiseRights
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Investment in Subsidiaries 0gpi_InvestmentinSubsidiaries
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
0gpi_InvestmentinSubsidiaries
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Other Assets, Noncurrent 10,120us-gaap_OtherAssetsNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
14,891us-gaap_OtherAssetsNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Total assets 3,819,638us-gaap_Assets
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
3,466,357us-gaap_Assets
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Floorplan Notes Payable Credit Facility Gross 1,137,743gpi_FloorplanNotesPayableCreditFacilityGross
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
1,125,030gpi_FloorplanNotesPayableCreditFacilityGross
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Floorplan Offset (39,616)gpi_FloorplanOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
(56,198)gpi_FloorplanOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Floorplan Notes Payable Manufacturer Affiliates 207,329gpi_FloorplanNotesPayableManufacturerAffiliates
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
248,584gpi_FloorplanNotesPayableManufacturerAffiliates
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
FMCC Offset (22,500)gpi_FMCCOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
     
Long-term Debt and Capital Lease Obligations, Current 61,185us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
24,428us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Accounts Payable, Current 176,143us-gaap_AccountsPayableCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
158,124us-gaap_AccountsPayableCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Intercompany accounts payable current 0gpi_Intercompanyaccountspayablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
0gpi_Intercompanyaccountspayablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Accrued Liabilities, Current 149,700us-gaap_AccruedLiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
118,529us-gaap_AccruedLiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Total current liabilities 1,669,984us-gaap_LiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
1,618,497us-gaap_LiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Long-term Debt and Capital Lease Obligations 347,202us-gaap_LongTermDebtAndCapitalLeaseObligations
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
328,090us-gaap_LongTermDebtAndCapitalLeaseObligations
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Derivative Liability, Noncurrent 25,311us-gaap_DerivativeLiabilitiesNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
26,078us-gaap_DerivativeLiabilitiesNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Other Liabilities, Noncurrent 193,077gpi_Deferredincometaxesandotherliabilities
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
171,141gpi_Deferredincometaxesandotherliabilities
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Temporary Equity, Carrying Amount, Attributable to Parent   0us-gaap_TemporaryEquityCarryingAmountAttributableToParent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Stockholders' Equity Attributable to Parent 1,879,485us-gaap_StockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
1,615,049us-gaap_StockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Intercompany note receivable (295,421)gpi_Intercompanynotereceivable
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
(292,498)gpi_Intercompanynotereceivable
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Total liabilities and stockholders' equity 3,819,638us-gaap_LiabilitiesAndStockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
3,466,357us-gaap_LiabilitiesAndStockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_GuarantorSubsidiariesMember
   
Non-Guarantor Subsidiaries [Member]        
Cash and Cash Equivalents, at Carrying Value 15,596us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
15,909us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
309us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
8,033us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
Contracts In Transit And Vehicle Receivables Net 19,087gpi_ContractsInTransitAndVehicleReceivablesNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
7,694gpi_ContractsInTransitAndVehicleReceivablesNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Accounts, Notes, Loans and Financing Receivable, Net, Current 33,903us-gaap_AccountsNotesAndLoansReceivableNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
30,326us-gaap_AccountsNotesAndLoansReceivableNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Intercompany accounts receivable current 0gpi_Intercompanyaccountsreceivablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
0gpi_Intercompanyaccountsreceivablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Inventory, Net 214,683us-gaap_InventoryNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
203,256us-gaap_InventoryNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Deferred Tax Assets, Net, Current 0us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
0us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Prepaid Expense and Other Assets, Current 15,070us-gaap_PrepaidExpenseAndOtherAssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
13,448us-gaap_PrepaidExpenseAndOtherAssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Total current assets 298,339us-gaap_AssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
270,633us-gaap_AssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Property, Plant and Equipment, Net 111,325us-gaap_PropertyPlantAndEquipmentNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
80,770us-gaap_PropertyPlantAndEquipmentNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Goodwill 129,735us-gaap_Goodwill
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
124,834us-gaap_Goodwill
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Indefinite-Lived Franchise Rights 46,445us-gaap_IndefiniteLivedFranchiseRights
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
85,093us-gaap_IndefiniteLivedFranchiseRights
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Investment in Subsidiaries 0gpi_InvestmentinSubsidiaries
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
0gpi_InvestmentinSubsidiaries
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Other Assets, Noncurrent 11,441us-gaap_OtherAssetsNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
1,485us-gaap_OtherAssetsNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Total assets 597,285us-gaap_Assets
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
562,815us-gaap_Assets
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Floorplan Notes Payable Credit Facility Gross 5,503gpi_FloorplanNotesPayableCreditFacilityGross
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
18,074gpi_FloorplanNotesPayableCreditFacilityGross
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Floorplan Offset 0gpi_FloorplanOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
0gpi_FloorplanOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Floorplan Notes Payable Manufacturer Affiliates 100,327gpi_FloorplanNotesPayableManufacturerAffiliates
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
97,988gpi_FloorplanNotesPayableManufacturerAffiliates
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
FMCC Offset 0gpi_FMCCOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
     
Long-term Debt and Capital Lease Obligations, Current 11,445us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
11,797us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Accounts Payable, Current 112,177us-gaap_AccountsPayableCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
96,806us-gaap_AccountsPayableCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Intercompany accounts payable current 276,217gpi_Intercompanyaccountspayablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
212,592gpi_Intercompanyaccountspayablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Accrued Liabilities, Current 22,763us-gaap_AccruedLiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
22,014us-gaap_AccruedLiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Total current liabilities 528,432us-gaap_LiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
459,271us-gaap_LiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Long-term Debt and Capital Lease Obligations 51,823us-gaap_LongTermDebtAndCapitalLeaseObligations
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
30,962us-gaap_LongTermDebtAndCapitalLeaseObligations
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Derivative Liability, Noncurrent 0us-gaap_DerivativeLiabilitiesNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
0us-gaap_DerivativeLiabilitiesNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Other Liabilities, Noncurrent 14,058gpi_Deferredincometaxesandotherliabilities
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
29,125gpi_Deferredincometaxesandotherliabilities
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Temporary Equity, Carrying Amount, Attributable to Parent   0us-gaap_TemporaryEquityCarryingAmountAttributableToParent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Stockholders' Equity Attributable to Parent 2,972us-gaap_StockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
43,457us-gaap_StockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Intercompany note receivable 0gpi_Intercompanynotereceivable
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
0gpi_Intercompanynotereceivable
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Total liabilities and stockholders' equity 597,285us-gaap_LiabilitiesAndStockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
562,815us-gaap_LiabilitiesAndStockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_NonGuarantorSubsidiariesMember
   
Consolidation, Eliminations [Member]        
Cash and Cash Equivalents, at Carrying Value 0us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_CashAndCashEquivalentsAtCarryingValue
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Contracts In Transit And Vehicle Receivables Net 0gpi_ContractsInTransitAndVehicleReceivablesNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0gpi_ContractsInTransitAndVehicleReceivablesNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Accounts, Notes, Loans and Financing Receivable, Net, Current 0us-gaap_AccountsNotesAndLoansReceivableNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_AccountsNotesAndLoansReceivableNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Intercompany accounts receivable current (276,217)gpi_Intercompanyaccountsreceivablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
(212,592)gpi_Intercompanyaccountsreceivablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Inventory, Net 0us-gaap_InventoryNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_InventoryNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Deferred Tax Assets, Net, Current 0us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Prepaid Expense and Other Assets, Current 0us-gaap_PrepaidExpenseAndOtherAssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_PrepaidExpenseAndOtherAssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Total current assets (276,217)us-gaap_AssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
(212,592)us-gaap_AssetsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Property, Plant and Equipment, Net 0us-gaap_PropertyPlantAndEquipmentNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_PropertyPlantAndEquipmentNet
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Goodwill 0us-gaap_Goodwill
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_Goodwill
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Indefinite-Lived Franchise Rights 0us-gaap_IndefiniteLivedFranchiseRights
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_IndefiniteLivedFranchiseRights
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Investment in Subsidiaries (1,964,442)gpi_InvestmentinSubsidiaries
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
(1,710,185)gpi_InvestmentinSubsidiaries
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Other Assets, Noncurrent 0us-gaap_OtherAssetsNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_OtherAssetsNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Total assets (2,240,659)us-gaap_Assets
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
(1,922,777)us-gaap_Assets
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Floorplan Notes Payable Credit Facility Gross 0gpi_FloorplanNotesPayableCreditFacilityGross
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0gpi_FloorplanNotesPayableCreditFacilityGross
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Floorplan Offset 0gpi_FloorplanOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0gpi_FloorplanOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Floorplan Notes Payable Manufacturer Affiliates 0gpi_FloorplanNotesPayableManufacturerAffiliates
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0gpi_FloorplanNotesPayableManufacturerAffiliates
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
FMCC Offset 0gpi_FMCCOffset
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
     
Long-term Debt and Capital Lease Obligations, Current 0us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Accounts Payable, Current 0us-gaap_AccountsPayableCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_AccountsPayableCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Intercompany accounts payable current (571,638)gpi_Intercompanyaccountspayablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
(505,090)gpi_Intercompanyaccountspayablecurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Accrued Liabilities, Current 0us-gaap_AccruedLiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_AccruedLiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Total current liabilities (571,638)us-gaap_LiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
(505,090)us-gaap_LiabilitiesCurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Long-term Debt and Capital Lease Obligations 0us-gaap_LongTermDebtAndCapitalLeaseObligations
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_LongTermDebtAndCapitalLeaseObligations
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Derivative Liability, Noncurrent 0us-gaap_DerivativeLiabilitiesNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0us-gaap_DerivativeLiabilitiesNoncurrent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Other Liabilities, Noncurrent 0gpi_Deferredincometaxesandotherliabilities
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
0gpi_Deferredincometaxesandotherliabilities
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Temporary Equity, Carrying Amount, Attributable to Parent   0us-gaap_TemporaryEquityCarryingAmountAttributableToParent
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Stockholders' Equity Attributable to Parent (1,964,442)us-gaap_StockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
(1,710,185)us-gaap_StockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Intercompany note receivable 295,421gpi_Intercompanynotereceivable
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
292,498gpi_Intercompanynotereceivable
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
   
Total liabilities and stockholders' equity $ (2,240,659)us-gaap_LiabilitiesAndStockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember
$ (1,922,777)us-gaap_LiabilitiesAndStockholdersEquity
/ gpi_CondensedconsolidatedfinancialinformationentitiesAxis
= us-gaap_ConsolidationEliminationsMember