Shared-Based Compensation - Reconciliation of Option Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of options, Outstanding, Beginning Balance	1,233
Number of Options, Granted	96
Number of Options, Exercised	(29)
Number of Options, Forfeited or expired	(8)
Number of Options, Outstanding, Ending Balance	1,292
Number of Options, Options Exercisable	840
Weighted-Average Exercise Price, Outstanding, Beginning Balance	$ 10.65
Weighted-Average Exercise Price, Granted	$ 19.63
Weighted-Average Exercise Price, Exercised	$ 12.62
Weighted-Average Exercise Price, Forfeited or expired	$ 12.62
Weighted-Average Exercise Price, Outstanding, Ending Balance	$ 11.26
Weighted-Average Exercise Price, Options exercisable	$ 10.79
Weighted-Average Remaining Contractual Term, Outstanding, Ending Balance	6 years 7 months 6 days
Weighted- Average Remaining Contractual Term, Options exercisable	5 years 4 months 24 days
Aggregate Intrinsic Value, Outstanding, Ending Balance	$ 10,900
Aggregate Intrinsic Value, Options exercisable	$ 7,474