Stock Option Activity (Detail) (Stock Options, USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010
Stock Options
Number of Shares
Outstanding at beginning of period		2,957,515	2,553,611
Granted	35,667		902,977	[1]		1,798,611
Exercised		(1,424,273)	(184,335)
Forfeited and canceled		(55,419)	(314,738)
Outstanding at end of period		1,477,823	2,957,515		2,553,611
Vested and expected to vest at end of period		1,439,712
Exercisable at end of period		798,141
Weighted-Average Exercise Price per Share
Outstanding at beginning of period		$ 4.66	$ 3.11
Granted	$ 3.08		$ 9.76	[1]		$ 3.08
Exercised		$ 3.87	$ 1.70
Forfeited and canceled		$ 7.45	$ 8.35
Outstanding at end of period		$ 5.36	$ 4.66		$ 3.11
Vested and expected to vest at end of period		$ 5.31
Exercisable at end of period		$ 4.35
Weighted-Average Remaining Contractual Term (in years)
Outstanding at end of period		4 years 3 months 18 days	4 years 2 months 12 days		5 years 3 months 18 days
Vested and expected to vest at end of period		4 years 3 months 18 days
Exercisable at end of period		4 years 1 month 6 days
Aggregate Intrinsic Value
Outstanding at end of period		$ 55,989	$ 60,383		$ 15,951
Vested and expected to vest at end of period		54,630
Exercisable at end of period		$ 31,052

[1] On May 9, 2012, the Company's Board of Directors specified the performance criteria for the stock options granted during the year ended December 31, 2011 for the purchase of 54,000 ordinary shares at an exercise price of $7.97. The performance criteria are based on Company operating metrics for 2012. As a result, as of May 9, 2012, these stock options were deemed granted for accounting purposes.