Long-Term Debt (Schedule of Long Term Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Aug. 07, 2018	Dec. 31, 2017	Jul. 01, 2016
Secured Term Loans	$ 519,850		$ 551,913
Revolving Credit Facility	634,850
Unamortized deferred financing costs	(24,063)		(14,103)
Total long-term debt, net of unamortized deferred financing costs	610,787		630,597
Less: current portion of long-term debt	28,300		28,300
Long term debt, noncurrent	582,487		602,297
Revolving Credit Facility [Member]
Revolving Credit Facility	115,000		$ 92,787
BoA Credit Agreement [Member]
Total long-term debt, net of unamortized deferred financing costs				$ 258,000
BoA Term Loans [Member]
Total long-term debt, net of unamortized deferred financing costs	$ 5,000
Revolving Loans [Member]
Total long-term debt, net of unamortized deferred financing costs		$ 115,000