Employee Benefit Plans - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Expected return on plan assets (as a percent)			8.00%
Discretionary contributions towards 401(k) Plan, maximum (as a percent)			4.00%	4.00%
Discretionary contributions to 401 (k) plans	$ 487	$ 554	$ 2,051	$ 1,945
Contributions to various defined contribution plans	$ 1,845	$ 1,608	$ 5,350	$ 4,619