Long-Term Debt (Schedule of Long Term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Jul. 01, 2016
Unamortized deferred financing costs	$ (22,608)	$ (24,063)
Total long-term debt, net of unamortized deferred financing costs	439,081	610,787
Less: current portion of long-term debt	21,000	28,300
Long term debt, noncurrent	418,081	582,487
BoA Term Loans [Member]
Secured Term Loans	456,331	519,850
Revolving Loans [Member]
Revolving Credit Facility	$ 5,358	$ 115,000
Total long-term debt, net of unamortized deferred financing costs			$ 115,000