Acquisitions - Estimated Fair Values of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Jan. 31, 2017	Nov. 18, 2016	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016
Business Acquisition [Line Items]
Goodwill	$ 168,829		$ 157,250	$ 76,357	$ 76,357
Taylor Brands, LLC and Crimson Trace Corporation
Business Acquisition [Line Items]
Accounts receivable			8,854
Inventories			24,947
Other current assets			300
Property, plant, and equipment			6,851
Intangibles			84,100
Goodwill			80,564
Total assets acquired			205,616
Accounts payable			5,066
Accrued expenses			1,014
Accrued payroll			689
Accrued income taxes			32
Accrued warranty			98
Deferred income taxes			20,658
Total liabilities assumed			27,557
Net assets acquired			178,059
Taylor Brands, LLC and Crimson Trace Corporation | As Initially Reported
Business Acquisition [Line Items]
Accounts receivable			8,937
Inventories			24,359
Other current assets			379
Property, plant, and equipment			6,851
Intangibles			84,100
Goodwill			80,893
Total assets acquired			205,519
Accounts payable			5,066
Accrued expenses			946
Accrued payroll			689
Accrued income taxes			3
Accrued warranty			98
Deferred income taxes			20,658
Total liabilities assumed			27,460
Net assets acquired			178,059
Taylor Brands, LLC and Crimson Trace Corporation | Measurement Period Adjustments
Business Acquisition [Line Items]
Accounts receivable			(83)
Inventories			588
Other current assets			(79)
Goodwill			(329)
Total assets acquired			97
Accrued expenses			68
Accrued income taxes			29
Total liabilities assumed			$ 97
Ultimate Survival Technologies, Inc.
Business Acquisition [Line Items]
Accounts receivable		$ 2,698
Inventories		6,910
Other current assets		51
Property, plant, and equipment		1,381
Intangibles		13,750
Goodwill		11,908
Total assets acquired		36,698
Accounts payable		1,148
Accrued expenses		27
Accrued payroll		811
Accrued income taxes		3
Total liabilities assumed		1,989
Net assets acquired		$ 34,709