Acquisitions - Summary of Unaudited Pro Forma Financial Result (Detail) - Animal Health International [Member] - USD ($) $ in Thousands	9 Months Ended
Jan. 30, 2016	Jan. 24, 2015
Business Acquisition [Line Items]
Pro forma net sales	$ 4,125,969	$ 4,033,188
Pro forma net income from continuing operations	$ 128,174	$ 122,842

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.

No definition available.

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- Definition

The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect, for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

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- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

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