Goodwill and Identified Intangible Assets - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Percentage of estimated fair value exceeding the carrying value	21.00%
Amortization expense for identified intangibles	$ 29,204	$ 30,420	$ 17,425
Cost of revenue [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense for identified intangibles	$ 20,500	$ 21,500	$ 12,500