Stock-based Compensation - Total Stock-Based Compensation Expense Recognized (Detail) - USD ($) $ 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]
Stock-based compensation expenses	$ 16,593	$ 16,516	$ 21,100
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expenses	770	1,747	4,321
Restricted Stock and Restricted Stock units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expenses	14,395	14,417	12,326
Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expenses	$ 1,428	$ 352	$ 4,453