Debt - Long-Term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Less - unamortized original issue discount	$ (7,726)	$ (10,053)
Total debt, net of unamortized discounts	354,462	356,822
Current portion of long-term debt, net of unamortized discounts	(12,188)	(10,313)
Long-term debt, net of unamortized discounts	342,274	346,509
2018 Credit Agreement | 2018 Term Loan
Debt Instrument [Line Items]
Total long-term debt, gross	132,188	136,875
Less – deferred financing costs	(1,433)	(1,715)
Total debt, net of unamortized discounts	130,755	135,160
Senior Convertible Notes 2016
Debt Instrument [Line Items]
Total long-term debt, gross	230,000	230,000
Less - unamortized original issue discount	(4,534)	(6,004)
Less – deferred financing costs	(1,759)	(2,334)
Total debt, net of unamortized discounts	$ 223,707	$ 221,662