Income Taxes - Reconciliation of the Beginning and Ending Amount of Gross Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Balance, beginning of year	$ 24,049	$ 12,900	$ 6,342
Increases to tax positions related to the current year	12,158	11,854	5,631
Increases to tax positions related to the prior year	3,936	540	927
Reductions due to lapsed statute of limitations
Decreases to tax positions related to the prior year	(3,640)
Settlements during current year	(76)	(1,245)
Balance, end of year	$ 36,427	$ 24,049	$ 12,900