Income Taxes - Reconciliation of Gross Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits [Line Items]
Balance at beginning of year	$ 27,734	$ 29,128	$ 18,302
Increases in tax positions for current year	18,230	230	14,759
Increases in tax positions for prior years	2,315	5,075	2,594
Decreases in tax positions for prior years	(6,192)	(3,697)	(1,872)
Settlement of tax matters	(1,232)	(2,127)	(3,369)
Lapse of applicable statutes of limitations	(377)	(875)	(1,286)
Balance at end of year	$ 40,478	$ 27,734	$ 29,128