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v3.10.0.1

Annual Financial Information (Details) | Dec. 31, 2018 town international_region state dealership
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Business and Organization [Line Items] |
Number of international regions | international_region | 2
U.S. |
Business and Organization [Line Items] |
Number of states in which the entity operates | state | 15
Number of dealerships | 118
U.K. |
Business and Organization [Line Items] |
Number of towns in which the entity operates | town | 32
Number of dealerships | 47
Brazil |
Business and Organization [Line Items] |
Number of states in which the entity operates | state | 4
Number of dealerships | 18

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- Definition Business And Organization [Line Items] + References No definition available. + Details
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Namespace Prefix: | gpi_
Data Type: | xbrli:stringItemType
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- Definition Number of dealerships. + References No definition available. + Details
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Namespace Prefix: | gpi_
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Balance Type: | na
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- Definition Number of Towns in which Entity Operates + References No definition available. + Details
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- Definition Number of international regions + References No definition available. + Details
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Namespace Prefix: | gpi_
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Balance Type: | na
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- Definition The number of states the entity operates in as of the balance sheet date. + References No definition available. + Details
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Data Type: | xbrli:integerItemType
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- Details
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- Details
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- Details
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Namespace Prefix: |
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Period Type: |