Segments and Geographic Areas - Geographic Information about Revenue and Long-Lived Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 193,720	$ 164,749	$ 135,718	$ 128,467	$ 131,951	$ 121,607	$ 117,482	$ 113,623	$ 622,654	$ 484,663	$ 432,431
Long-lived assets	903,452				124,054				903,452	124,054	126,234
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									408,022	326,864	290,905
Long-lived assets	201,455				102,550				201,455	102,550	112,366
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									104,825	71,916	69,755
Long-lived assets	693,445				13,424				693,445	13,424	4,876
Other Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									109,807	85,883	71,771
Long-lived assets	$ 8,552				$ 8,080				$ 8,552	$ 8,080	$ 8,992