Income Taxes - Schedule of Deferred Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Accrued expenses	$ 428	$ 221
Allowance for doubtful accounts	183	177
Contract overrun reserves	2,178	139
Deferred compensation	141	164
Employment-related reserves	2,982	2,657
Environmental reserves	778	762
Federal tax credit carryforwards	3,290	2,454
Inventory reserves	5,519	1,942
Pension obligation	2,297	4,445
Prepaid insurance	(666)	406
State net operating loss carryforwards	995	818
State tax credit carryforwards	3,887	3,253
Stock-based compensation	3,077	4,012
Workers’ compensation	121	35
Other	1,355	1,208
Deferred Tax Assets, Net of Valuation Allowance, Total	26,565	22,693
Depreciation	(6,182)	(5,424)
Goodwill	(8,819)	(5,764)
Intangibles	(62,777)	(66,015)
Unbilled receivables	(1,409)	(1,251)
Valuation allowance	(5,017)	(4,120)
Net deferred tax liabilities	$ (57,639)	$ (59,881)