Senior Secured Notes (Details)	3 Months Ended
	Mar. 31, 2021 USD ($) $ / shares	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Senior Notes [Line Items]
Secured Long-term Debt, Noncurrent	$ 464,222,000		$ 460,656,000
1.50% Senior Secured Convertible Notes Due 2021 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	1.50%		1.50%
Senior Notes, Principal amount	$ 65,485,000		$ 65,485,000
Senior Secured Notes, Unamortized Debt Discount	914,000		1,828,000
Senior Notes, unamortized deferred financing costs	87,000		175,000
Secured Long-term Debt, Noncurrent	$ 64,484,000		$ 63,482,000
Debt Instrument, Convertible, Conversion Ratio	24.6914
Debt Instrument, Principal Amount of Note	$ 1,000
Senior Convertible Notes, conversion price | $ / shares	$ 40.50
Interest Expense, Debt	$ 1,200,000	$ 2,900,000
10.0% Senior Secured Notes due 2025 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	10.00%		10.00%
Senior Notes, Principal amount	$ 446,675,000		$ 446,675,000
Senior Secured Notes, Unamortized Debt Discount	36,085,000		37,943,000
Senior Notes, unamortized deferred financing costs	10,852,000		11,558,000
Secured Long-term Debt, Noncurrent	399,738,000		397,174,000
Senior Secured Notes [Member]
Senior Notes [Line Items]
Senior Notes, Principal amount	512,160,000		512,160,000
Senior Secured Notes, Unamortized Debt Discount	36,999,000		39,771,000
Senior Notes, unamortized deferred financing costs	$ 10,939,000		$ 11,733,000