XML 53 R42.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Acquisitions and Dispositions Acquisitions and Dispositions (Details textuals) $ in Millions | 6 Months Ended
--- | ---
Jun. 30, 2016 USD ($) | Jun. 30, 2015 USD ($)
Acquisitions and Dispositions (Textual) [Abstract] |  |
Business Combination, Consideration Transferred | $ 60.4 |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents | 3.9 |
Business Combination, Contingent Consideration, Payable to Sellers | $ 1.8 |
Gain (Loss) on Disposition of Business |  | $ 0.7
U.S. [Member] |  |
Acquisitions and Dispositions (Textual) [Abstract] |  |
Number Of Dealerships Acquired |  | 2
Number of Dealerships Disposed | 2 | 1
Gain (Loss) on Disposition of Business | $ 0.7 |
Number of Franchises Disposed |  | 1
U.K. [Member] |  |
Acquisitions and Dispositions (Textual) [Abstract] |  |
Number Of Dealerships Acquired | 12 |
Number of Franchises Acquired | 17 |
Brazil [Member] |  |
Acquisitions and Dispositions (Textual) [Abstract] |  |
Number Of Dealerships Acquired | 1 |
Number of Franchises Acquired | 2 |
Number Of Dealerships Opened | 2 |
Number Of Franchises Awarded | 2 |
Number of Dealerships Disposed | 4 |
Gain (Loss) on Disposition of Business | $ (1.4) |
Number of Franchises Disposed |  | 2

X
- Definition Number of dealerships acquired. + References No definition available. + Details
Name: | gpi_NumberOfDealershipsAcquired
Namespace Prefix: | gpi_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Dealerships Opened + References No definition available. + Details
Name: | gpi_NumberOfDealershipsOpened
Namespace Prefix: | gpi_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of franchises acquired. + References No definition available. + Details
Name: | gpi_NumberOfFranchisesAcquired
Namespace Prefix: | gpi_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Franchises Awarded + References No definition available. + Details
Name: | gpi_NumberOfFranchisesAwarded
Namespace Prefix: | gpi_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of franchises disposed. + References No definition available. + Details
Name: | gpi_NumberOfFranchisesDisposed
Namespace Prefix: | gpi_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Dealerships Disposed + References No definition available. + Details
Name: | gpi_NumberofDealershipsDisposed
Namespace Prefix: | gpi_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477 + Details
Name: | us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of liability recognized arising from contingent consideration in a business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 35 -Paragraph 1 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=6911338&loc=d3e6819-128478 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 25 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476 + Details
Name: | us-gaap_BusinessCombinationContingentConsiderationLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_BusinessCombinationDescriptionAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=56956791&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Gain (loss) from sale or disposal of an organization or integrated set of activities (for example, but not limited to, a partnership or corporation) engaged in providing a product or service in a commercial, industrial, or professional environment. + References No definition available. + Details
Name: | us-gaap_GainLossOnSaleOfBusiness
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=gpi_UnitedStatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=gpi_UnitedKingdomMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=gpi_BrazilMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |