Stock-Based Compensation - Schedule of Standard and Market-based Stock Options Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Standard Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning outstanding balance (in shares)	3,486,157	3,227,167	3,155,631
Granted (in shares)	525,840	604,620	1,058,700
Exercised (in shares)	(239,071)	(205,744)	(956,633)
Forfeited (in shares)	(116,425)	(102,454)	(10,531)
Expired (in shares)	(59,968)	(37,432)	(20,000)
Ending outstanding balance (in shares)	3,596,533	3,486,157	3,227,167
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning balance (in dollars per share)	$ 8.30	$ 7.78	$ 6.65
Weighted Average Exercise Price, Granted (in dollars per share)	10.15	10.32	10.20
Weighted Average Exercise Price, Exercised (in dollars per share)	6.82	6.34	6.68
Weighted Average Exercise Price, Forfeited (in dollars per share)	12.38	7.20	8.24
Weighted Average Exercise Price, Expired (in dollars per share)	13.75	10.19	9.01
Weighted Average Exercise Price, Ending balance (in dollars per share)	8.45	8.30	7.78
Weighted Average Fair Value Of Options Granted (in dollars per share)	$ 4.56	$ 4.93	$ 5.63
Aggregate Intrinsic Value of Options Exercised	$ 1,186	$ 1,125	$ 5,774
Market Condition Based Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning outstanding balance (in shares)	50,000	0
Granted (in shares)	150,000	50,000
Exercised (in shares)	0	0
Forfeited (in shares)	0	0
Expired (in shares)	0	0
Ending outstanding balance (in shares)	200,000	50,000	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning balance (in dollars per share)	$ 11.94	$ 0.00
Weighted Average Exercise Price, Granted (in dollars per share)	8.09	11.94
Weighted Average Exercise Price, Exercised (in dollars per share)	0.00	0.00
Weighted Average Exercise Price, Forfeited (in dollars per share)	0.00	0.00
Weighted Average Exercise Price, Expired (in dollars per share)	0.00	0.00
Weighted Average Exercise Price, Ending balance (in dollars per share)	9.05	11.94	$ 0.00
Weighted Average Fair Value Of Options Granted (in dollars per share)	$ 3.64	$ 5.71
Aggregate Intrinsic Value of Options Exercised	$ 0	$ 0