Stock Incentive Plan - Summary of Stock Option Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of shares, Outstanding, Beginning balance		2,389
Number of shares, Granted	0	35
Number of shares, Exercised		(500)
Number of shares, Forfeited		(75)
Number of shares, Outstanding, Ending balance	1,849	1,849	2,389
Number of shares, Exercisable, Ending balance	1,332	1,332	1,451
Weighted Average Exercise Price, Outstanding, Beginning balance		$ 26.85
Weighted Average Exercise Price, Granted		$ 41.03
Weighted Average Exercise Price, Exercised		$ 20.62
Weighted Average Exercise Price, Forfeited		$ 33.36
Weighted Average Exercise Price, Outstanding, Ending balance	$ 28.54	$ 28.54	$ 26.85
Weighted Average Exercise Price, Exercisable, Ending balance	$ 26.72	$ 26.72	$ 23.45
Weighted Average Remaining Contractual Term (Years), Outstanding		6 years 3 months 18 days	6 years 4 months 24 days
Weighted Average Remaining Contractual Term (Years), Exercisable		5 years 8 months 12 days	5 years 4 months 24 days
Aggregate Intrinsic Value, Outstanding, Beginning balance		$ 22,330
Aggregate Intrinsic Value, Exercised		11,037
Aggregate Intrinsic Value, Outstanding, Ending balance	33,444	33,444	22,330
Aggregate Intrinsic Value, Exercisable, Ending balance	$ 26,522	$ 26,522	$ 17,855