Stock-Based Compensation - Summary of Weighted Average Grant-Date Fair Value Granted and Total Fair Value of Restricted Shares and Restricted Stock Units Vested (Detail) - Restricted Shares and Restricted Stock Units (RSU's) [Member] - 2011 Equity Incentive Plan [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Shares	441	500	706
Weighted average grant-date fair value	$ 25.06	$ 19.77	$ 15.25
Fair value of vested	$ 2,019	$ 895	$ 366