Summary of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 24,032	$ 10,349
Accumulated Amortization	9,407	9,254
Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	19,882	6,199
Weighted Average Amortization Period	3 years 7 months 6 days	3 years 9 months 18 days
Accumulated Amortization	5,607	5,474
Customer Contracts
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,400	2,400
Weighted Average Amortization Period	3 years	3 years
Accumulated Amortization	2,400	2,400
Trade Names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	630	630
Weighted Average Amortization Period	3 years	3 years
Accumulated Amortization	630	630
Non-compete Agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	410	410
Weighted Average Amortization Period	1 year 2 months 12 days	1 year 2 months 12 days
Accumulated Amortization	410	410
Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	475	475
Weighted Average Amortization Period	11 years	11 years
Accumulated Amortization	125	105
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	235	235
Weighted Average Amortization Period	3 years	3 years
Accumulated Amortization	$ 235	$ 235