Goodwill and Intangible Assets - Summary of Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Cost	$ 32,548	$ 32,548
Accumulated Amortization	26,753	25,544
Net Book Value	5,795	7,004
Customer contracts and relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	17,381	17,381
Accumulated Amortization	13,425	12,463
Net Book Value	3,956	4,918
Patents and technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	7,878	7,878
Accumulated Amortization	7,452	7,378
Net Book Value	426	500
Trademarks and trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	3,988	3,988
Accumulated Amortization	2,720	2,575
Net Book Value	1,268	1,413
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	3,301	3,301
Accumulated Amortization	3,156	3,128
Net Book Value	$ 145	$ 173