Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Aug. 13, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Long-term debt	$ 739,644		$ 578,701
2018 Term Loan Facility
Line of Credit Facility [Line Items]
Long-term debt, gross	446,625
Unamortized deferred financing costs	(7,784)
Revolving Credit Facilities
Line of Credit Facility [Line Items]
Long-term debt, gross	305,704		47,486
Unamortized deferred financing costs	$ (4,901)	$ (700)	(3,164)
Senior secured notes | Senior Secured Notes Due 2021
Line of Credit Facility [Line Items]
Long-term debt, gross			575,000
Unamortized deferred financing costs			$ (40,621)