Debt - Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Mar. 05, 2018
Debt Instrument [Line Items]
Total long-term debt, gross	$ 366,875
Less – unamortized original issue discount	(10,053)	$ (14,549)
Less – deferred financing costs			$ (2,800)
Total debt, net of unamortized discounts	356,822	359,826
Current portion of long-term debt, net of unamortized discounts	(10,313)	(7,500)
Long-term debt, net of unamortized discounts	346,509	352,326
2018 Credit Agreement
Debt Instrument [Line Items]
Less – deferred financing costs	(1,700)
2018 Credit Agreement | 2018 Term Loan
Debt Instrument [Line Items]
Total long-term debt, gross	136,875	144,375
Less – deferred financing costs	(1,715)	(2,281)
Total debt, net of unamortized discounts	135,160	142,094	$ 150,000
2016 Convertible Notes
Debt Instrument [Line Items]
Total long-term debt, gross	230,000	230,000
Less – unamortized original issue discount	(6,004)	(8,823)
Less – deferred financing costs	(2,334)	(3,445)
Total debt, net of unamortized discounts	$ 221,662	$ 217,732