Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 03, 2015
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 82,554,000	$ 82,554,000	$ 82,554,000
Goodwill impairment	57,200,000	0	57,243,000	$ 0
Carrying value of trade names	0		0		$ 32,900,000
Amortization expense of intangible asset		$ 9,000,000	10,000,000	$ 10,400,000
Minimum
Goodwill And Intangible Assets [Line Items]
Acquired intangible assets amortization period		14 years
Maximum
Goodwill And Intangible Assets [Line Items]
Acquired intangible assets amortization period		18 years
SS
Goodwill And Intangible Assets [Line Items]
Goodwill	0	$ 0	0
Goodwill impairment	$ 57,200,000		57,200,000
ES
Goodwill And Intangible Assets [Line Items]
Goodwill		82,600,000
Percentage exceeded from carrying value	42.00%
Electronic Systems
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 82,554,000	$ 82,554,000	$ 82,554,000
Goodwill fair value in excess of carrying value		32.00%
Miltec
Goodwill And Intangible Assets [Line Items]
Percentage exceeded from carrying value	18.00%
Trade names
Goodwill And Intangible Assets [Line Items]
Impairment of trade names	$ 32,900,000