Financial Commitments (Summary of Interest Expense as Reported in the Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Other interest	$ 577	$ 540	$ 1,616	$ 1,656
Cash portion of loss on extinguishment	786	0	786	0
Total cash interest expense	14,485	13,957	40,339	41,462
Non-cash interest expense			18,960	9,790
Non-cash portion of loss on extinguishment	8,311	0	8,311	0
Total non-cash interest expense	11,128	3,348	18,174	9,790
Total interest expense	25,613	17,305	58,513	51,252
Term Loan B
Debt Instrument [Line Items]
Cash interest expense	2,919	0	2,919	0
Non-cash interest expense	$ 253	0	$ 253	0
Effective interest rates	6.50%		6.50%
Convertible Notes
Debt Instrument [Line Items]
Cash interest expense	$ 995	1,438	$ 3,870	4,313
Non-cash interest expense	$ 2,073	2,734	$ 7,870	8,013
Effective interest rates	9.39%		9.39%
2017 Senior Notes | Senior Notes
Debt Instrument [Line Items]
Cash interest expense	$ 8,594	8,594	$ 25,781	25,781
Non-cash interest expense	$ 229	213	$ 674	627
Effective interest rates	7.13%		7.13%
2020 Revolver
Debt Instrument [Line Items]
Cash interest expense	$ 26	0	$ 26	0
Non-cash interest expense	64	0	64	0
2017 Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Cash interest expense	588	3,385	5,341	9,712
Non-cash interest expense	$ 198	$ 401	$ 1,002	$ 1,150