Stock-Based Compensation - Stock-Based Compensation Expense, Income Tax Benefits Related to Stock-Based Compensation and Excess Tax Benefits (Provision) Recorded by Company (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefit (deficiency) from stock-based compensation			$ 2,060
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation (expense)	$ (3,547)	$ (1,288)	(5,729)	$ (3,284)
Income Taxes [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit	1,348	$ 486	2,177	1,215
Additional Paid-in Capital [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefit (deficiency) from stock-based compensation	$ 149		$ 2,060	$ 169