Goodwill and Intangible Assets - Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 58,038	$ 59,115
Accumulated Amortization	13,625	11,045
Net Carrying Amount	44,413	48,070
Trademarks and patents [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,013	1,065
Accumulated Amortization	250	227
Net Carrying Amount	763	838
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	36,020	36,479
Accumulated Amortization	10,450	8,394
Net Carrying Amount	25,570	28,085
Covenant not-to-compete [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	971	1,042
Accumulated Amortization	456	358
Net Carrying Amount	515	684
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	20,034	20,529
Accumulated Amortization	2,469	2,066
Net Carrying Amount	$ 17,565	$ 18,463