Stockholders' Equity - Summary of Restricted Stock Unit Activity (Detail) (Restricted Stock Units (RSUs) [Member], USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs outstanding at December 31, 2012	1,036,750
RSUs awarded	392,500	486,750	550,000
RSUs released	(341,843)
RSUs forfeited	(23,750)
RSUs outstanding at December 31, 2013	1,063,657	1,036,750
RSUs vested and expected to vest at December 31, 2013	925,882
RSUs outstanding at December, 31, 2013, Weighted-Average Remaining Contractual Term	1 year 5 months 16 days
RSUs vested and expected to vest at December 31, 2013, Weighted-Average Remaining Contractual Term	1 year 5 months 5 days
RSUs outstanding at December 31, 2013, Aggregate Intrinsic Value	$ 14,774
RSUs vested and expected to vest at December 31, 2013, Aggregate Intrinsic Value	$ 12,860