Stock Incentive Plans - Summary of Restricted Stock Activity (Detail) - Restricted Stock - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Number of Restricted Stock
Outstanding as of beginning of period (in shares)	982	811	38
Granted (in shares)	556	528	904
Vested (in shares)	(186)	(273)	(109)
Forfeited (in shares)	(59)	(84)	(22)
Outstanding as of end of period (in shares)	1,293	982	811
Weighted Average Grant Date Fair Value
Outstanding as of beginning of period (in dollars per share)	$ 18.55	$ 16.89	$ 12.11
Granted (in dollars per share)	24.01	20.18	16.72
Vested (in dollars per share)	18.28	17.37	14.15
Forfeited/Canceled (in dollars per share)	19.37	18.38	15.43
Outstanding as of end of period (in dollars per share)	$ 20.89	$ 18.55	$ 16.89
Total Intrinsic Value of Restricted Stock Vested
Vested	$ 4,580	$ 5,624	$ 2,092