Equity Compensation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Pre-tax compensation expense for unvested stock-based compensation grants	$ 6,900		$ 6,900
Service period applicable to the grantees on a weighted-average basis, years			1 year 6 months
RSUs vested and settled in shares of common stock, amount	$ 123	$ 18	$ 1,383	$ 1,942