Segment Information - Schedule of Results by Business Segment (Detail) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Jan. 31, 2017		Jan. 31, 2016	Jan. 31, 2017		Jan. 31, 2016
Segment Reporting Information [Line Items]
Total net sales	[1]	$ 233,523		$ 210,786	$ 674,002		$ 501,791
Cost of sales	[1]	134,212		124,128	389,517		300,048
Gross margin	[1]	99,311		86,658	284,485		201,743
Operating income/(loss)	[1]	50,209		50,148	154,888		101,747
Income tax expense/(benefit)	[1]	15,809		16,630	48,562		31,844
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total net sales	[1]	(4,037)		(861)	(9,126)		(1,504)
Cost of sales	[1]	(4,317)		(923)	(8,400)		(939)
Gross margin	[1]	280		62	(726)		(565)
Operating income/(loss)	[1]	14,726		4,959	38,778		13,314
Operating Segments
Segment Reporting Information [Line Items]
Total net sales	[1]	233,523		210,786	674,002		501,791
Corporate
Segment Reporting Information [Line Items]
Operating income/(loss)	[1]	(13,131)		(4,506)	(35,912)		(12,688)
Income tax expense/(benefit)	[1]	(2,865)		(1,872)	(9,796)		(7,572)
Firearms Division
Segment Reporting Information [Line Items]
Total net sales	[1]	197,025		194,650	583,900		448,408	[2]
Firearms Division | Intersegment Eliminations
Segment Reporting Information [Line Items]
Total net sales	[1]	1,090		795	2,816		795
Firearms Division | Operating Segments
Segment Reporting Information [Line Items]
Total net sales	[1]	198,115		195,445	586,716		449,203
Cost of sales	[1]	118,207		117,284	344,558		273,151	[2]
Gross margin	[1]	79,908		78,160	242,158		176,052
Operating income/(loss)	[1]	50,097		49,222	156,771		98,178
Income tax expense/(benefit)	[1]	19,453		18,299	60,216		38,682
Outdoor Products & Accessories
Segment Reporting Information [Line Items]
Total net sales	[1]	36,498		16,136	90,102		53,383	[2]
Outdoor Products & Accessories | Intersegment Eliminations
Segment Reporting Information [Line Items]
Total net sales	[1]	2,947		66	6,310		709
Outdoor Products & Accessories | Operating Segments
Segment Reporting Information [Line Items]
Total net sales	[1]	39,445		16,202	96,412		54,092
Cost of sales	[1]	20,322	[3]	7,767	53,359	[4]	27,836	[2]
Gross margin	[1]	19,123		8,436	43,053		26,256
Operating income/(loss)	[1]	(1,483)	[5]	473	(4,749)	[6]	2,943
Income tax expense/(benefit)	[1]	$ (779)		$ 203	$ (1,858)		$ 734

[1] We allocate all of corporate overhead expenses except for interest and income taxes, such as general and administrative expenses and other corporate-level expenses, to both our Firearms and Outdoor Products & Accessories segments.

[2] Effective October 1, 2015, our Thompson/Center accessories business was transitioned from our Firearms segment to our Outdoor Products & Accessories segment. As a result of this transition, we have reclassified $5.6 million and $4.6 million of revenue and cost of sales, respectively, from the Firearms segment to the Outdoor Products & Accessories segment for the nine months ended January 31, 2016.

[3] Amount includes $777,000 of additional cost of goods sold from the fair value inventory step-up and backlog expense in related to the Acquisitions.

[4] Amount includes $4.6 million of additional cost of goods sold from the fair value inventory step-up and backlog expense related to the Acquisitions.

[5] Amount includes $3.1 million of amortization of intangible assets identified as a result of the Acquisitions.

[6] Amount includes $5.1 million of amortization of intangible assets identified as a result of the Acquisitions.