XML 113 R97.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Long-Term Debt - All Long-Term Debt (Details) - USD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 08, 2015 | Jun. 02, 2014
Debt Instrument [Line Items] |  |  |  |  |
Impact of interest rate derivative instruments related to Mortgage Facility | $ 0.5 | $ 1.9 | $ 2.3 |  |
Interest expense related to capital leases and notes, net of interest income | 9.5 | 8.2 | 6.6 |  |
Capitalized interest costs | 1.3 | 1.6 | 0.7 |  |
Unamortized debt issuance cost | $ 3.1 |  |  |  |
5.00% Senior Note |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Interest rate | 5.00% |  |  |  | 5.00%
5.25% Senior Note |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Interest rate | 5.25% |  |  | 5.25% |
Convertible and Senior Notes |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Interest expense, excluding amortization of discounts and capitalized costs | $ 43.3 | 43.3 | 43.3 |  |
Amortization of discounts and capitalized cost | 2.2 | 2.2 | 2.1 |  |
Real Estate Credit Facility Real Estate Related Debt and Acquisition Line |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Interest expense, excluding amortization of discounts and capitalized costs | $ 20.3 | $ 15.0 | $ 13.7 |  |

X
- Definition Impact of interest rate derivative instruments related to mortgage facility. + References No definition available. + Details
Name: | gpi_ImpactOfInterestRateDerivativeInstrumentsRelatedToMortgageFacility
Namespace Prefix: | gpi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total interest expense related to capital leases, net of interest income. + References No definition available. + Details
Name: | gpi_InterestExpenseRelatedToCapitalLeasesAndVariousOtherNotesPayableNetOfInterestIncome
Namespace Prefix: | gpi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.8) -URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227 + Details
Name: | us-gaap_AmortizationOfDebtDiscountPremium
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -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 Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of interest capitalized during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 + Details
Name: | us-gaap_InterestCostsCapitalized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph 8 -URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227 + Details
Name: | us-gaap_InterestExpenseDebtExcludingAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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://fasb.org/us-gaap/role/ref/legacyRef -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
- Details
Name: | us-gaap_LongtermDebtTypeAxis=gpi_A5.00SeniorNoteMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=gpi_A5.25SeniorNoteMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=gpi_ConvertibleandSeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=gpi_RealEstateCreditFacilityRealEstateRelatedDebtandAcquisitionLineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |