Acquisitions - Additional Information (Detail) - Sealweld Corporation CAD in Millions, $ in Millions		6 Months Ended
Feb. 01, 2017 USD ($) CAD / $	Feb. 01, 2017 CAD CAD / $	Jan. 31, 2017
Business Acquisition [Line Items]
Acquisition date			Feb. 01, 2017
Subsequent Event
Business Acquisition [Line Items]
Cash consideration	$ 17.4	CAD 22.6
Exchange rate	0.77	0.77

Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 25
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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.

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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
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Foreign exchange rate used to translate amounts denominated in functional currency to reporting currency.

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