Goodwill and Other Intangible Assets - Carrying Amount of Finite-lived and Other Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 191,945	$ 183,845
Accumulated Amortization	79,853	69,152
Net Carrying Amount	112,092	114,693
Electronic Systems
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	164,545	164,545
Accumulated Amortization	62,108	52,688
Net Carrying Amount	102,437	111,857
Structural Systems
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	27,400	19,300
Accumulated Amortization	17,745	16,464
Net Carrying Amount	$ 9,655	2,836
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets (in years)	17 years
Gross Carrying Amount	$ 187,200	180,300
Accumulated Amortization	77,824	67,449
Net Carrying Amount	$ 109,376	112,851
Trade Names
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets (in years)	13 years
Gross Carrying Amount	$ 2,500	1,300
Accumulated Amortization	193	26
Net Carrying Amount	$ 2,307	1,274
Contract renewal
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets (in years)	14 years
Gross Carrying Amount	$ 1,845	1,845
Accumulated Amortization	1,625	1,493
Net Carrying Amount	$ 220	352
Technology
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets (in years)	15 years
Gross Carrying Amount	$ 400	400
Accumulated Amortization	211	184
Net Carrying Amount	$ 189	$ 216