XML 47 R68.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2

Financial Instruments and Fair Value Measurements - Schedule of Long-term Debt Carrying Value and Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Carrying Value
Debt Instrument [Line Items]
Debt, fair value	$ 885.1	$ 922.2
Carrying Value | 5.00% Senior Note
Debt Instrument [Line Items]
Debt, fair value	546.4	545.0
Carrying Value | 5.25% Senior Note
Debt Instrument [Line Items]
Debt, fair value	298.0	297.5
Carrying Value | Real estate related
Debt Instrument [Line Items]
Debt, fair value	40.7	79.7
Fair Value
Debt Instrument [Line Items]
Debt, fair value	910.3	884.3
Fair Value | 5.00% Senior Note
Debt Instrument [Line Items]
Debt, fair value	559.5	521.6
Fair Value | 5.25% Senior Note
Debt Instrument [Line Items]
Debt, fair value	309.7	286.5
Fair Value | Real estate related
Debt Instrument [Line Items]
Debt, fair value	$ 41.1	$ 76.2

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

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

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=gpi_A5.00SeniorNoteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=gpi_A5.25SeniorNoteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=gpi_RealEstateRelatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: