Schedule of Deferred Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Deferred Income Tax Assets and Liabilities [Line Items]
Accrued expenses	$ 386	$ 672
Allowance for doubtful accounts	213	195
Contract overrun reserves	139	192
Deferred compensation	164	1,139
Employment-related reserves	6,088	5,700
Environmental reserves	762	895
Inventory reserves	4,123	5,238
Pension obligation	4,445	4,574
Prepaid insurance	406	308
State net operating loss carryforwards	818	818
State tax credit carryforwards	3,253	1,849
Stock-based compensation	4,012	4,003
Workers' compensation	35	17
Other	970	286
Deferred Tax Assets, Net of Valuation Allowance, Total	25,814	25,886
Depreciation	(5,424)	(7,663)
Goodwill	(5,764)	(3,400)
Intangibles	(66,604)	(71,163)
Unbilled receivables	(1,251)	(1,675)
Valuation allowance	(4,120)	(2,008)
Net deferred tax assets (liabilities)	$ (57,349)	$ (60,023)