Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities, Current [Abstract]
Compensation	$ 34,752	$ 27,669
Interest and taxes	8,002	13,102
Customer rebates	10,517	10,303
Insurance	7,261	7,584
Other	14,935	11,734
Total accrued expenses	$ 75,467	$ 70,392