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Acquisitions Narrative (Details) | 6 Months Ended
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Oct. 31, 2017 store
Business Combinations [Abstract] |
Number of stores acquired | 14
Goodwill deductible for income tax purposes period (in years) | 15 years

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Balance Type: | na
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- References No definition available. + Details
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Namespace Prefix: | us-gaap_
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Period Type: | duration

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- Definition The number of businesses acquired by the entity during the period. + References No definition available. + Details
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Balance Type: | na
Period Type: | duration