Senior Secured Notes (Details) - USD ($) shares in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2020		Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019	Jun. 17, 2020	May 05, 2020	Dec. 31, 2019
Senior Secured Notes [Line Items]
Increase to Permitted Second Lien Debt									$ 827,500,000
Permitted Second Lien Debt		$ 1,000,000,000.0			$ 1,000,000,000.0
Class of Warrant or Right, Number of Securities Called by Warrants or Rights								5,900
Warrants Percent of Outstanding Stock								5.00%
Available Permitted Second Lien Debt Capacity [Member]
Senior Secured Notes [Line Items]
Permitted Second Lien Debt		$ 487,800,000			$ 487,800,000
10.0% Senior Secured Notes due 2025
Senior Secured Notes [Line Items]
Senior Notes, interest rate, stated percentage		10.00%			10.00%
Senior Notes, Principal amount		$ 446,675,000			$ 446,675,000			$ 446,700,000		$ 0
Senior Secured Notes, Unamortized Debt Discount		(41,340,000)			(41,340,000)
Senior Secured Notes, unamortized deferred financing costs		(11,596,000)			(11,596,000)
Senior Secured Notes, Principal Amount, Net		$ 393,739,000			$ 393,739,000
Senior Secured Notes, Debt Issuance Costs, Gross								11,700,000
Debt Instrument, Senior Notes, Initial Fair Value								$ 405,000,000.0
1.50% Senior Secured Convertible Notes Due 2021 [Member]
Senior Secured Notes [Line Items]
Senior Notes, interest rate, stated percentage		1.50%			1.50%
Senior Notes, Principal amount	[2]	$ 65,485,000	[1]		$ 65,485,000	[1]				$ 0
Senior Secured Notes, Unamortized Debt Discount	[1]	(3,592,000)			(3,592,000)
Senior Secured Notes, unamortized deferred financing costs	[1]	(349,000)			(349,000)
Senior Secured Notes, Principal Amount, Net	[1]	61,544,000			61,544,000
Interest Expense, Debt		2,600,000		$ 2,700,000	5,400,000		$ 5,400,000
Senior Secured Notes
Senior Secured Notes [Line Items]
Senior Notes, Principal amount		512,160,000			512,160,000
Senior Secured Notes, Unamortized Debt Discount		(44,932,000)			(44,932,000)
Senior Secured Notes, unamortized deferred financing costs		(11,945,000)			(11,945,000)
Senior Secured Notes, Principal Amount, Net		$ 455,283,000			$ 455,283,000

[1] (1) As discussed above, as required by the 2021 Notes Indenture and as permitted by the Credit Agreement, as the Company issued Permitted Second Lien Debt upon the closing of the Exchange Offers, its remaining 2021 Senior Convertible Notes contemporaneously became secured

[2] ⁽¹⁾ The Company’s 2021 Senior Convertible Notes became secured in the second quarter of 2020 upon closing of the Exchange Offers. Please refer to Note 5 - Long-Term Debt for additional information.