Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term debt	$ 824,375	$ 836,500
Less: unamortized loan fees	13,502	14,542
Total debt, net of unamortized loan fees	810,873	821,958
Current maturities of long term debt, net of unamortized loan fees	74,486	64,397
Long-term debt, less current maturities, net of unamortized loan fees	736,387	757,561
Term loan A-1
Debt Instrument [Line Items]
Long-term debt	424,375	436,500
Term loan A-2
Debt Instrument [Line Items]
Long-term debt	$ 400,000	$ 400,000