Long-Term Debt - 2024 PIK Notes (Details) - USD ($)		3 Months Ended
	Feb. 08, 2019	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Principal amount		$ 130,000,000	$ 334,473,000
Payment in Kind (PIK) Note | 10% Secured PIK Notes due 2024
Debt Instrument [Line Items]
Principal amount	$ 80,000,000	$ 80,000,000	0
Stated interest rate	10.00%
Debt covenant, compliance, interest payment, period of default		30 days
Debt covenant, compliance, default period in performance or breach of certain covenants		60 days
Debt covenant, compliance, default period in failure to comply with certain restrictive covenants		30 days
Debt covenant, compliance, default period in failure to comply with reporting obligations		120 days
Debt covenant, compliance, holders written notice to trustees, percent of principal amount		25.00%
Debt covenant, compliance, amount of judgment or decree, event of default		$ 10,000,000.0
Debt covenant, compliance, amount of judgment or decree, default period		60 days
Debt covenant, compliance, lien granted under note documents, fair market value		$ 15,000,000
Debt covenant, compliance, lien granted under note documents, period lien ceases to be enforceable		45 days
Debt covenant, compliance, second priority lien granted under note documents, fair market value		$ 15,000,000
Debt covenant, compliance, second priority lien granted under note documents, period lien ceases to be enforceable		45 days
Debt covenant, compliance, notice of default to holders of notes, period		90 days
Payment in Kind (PIK) Note | 10% Secured PIK Notes due 2024 | Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price, percentage	102.00%
Payment in Kind (PIK) Note | 10% Secured PIK Notes due 2024 | Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Redemption price, percentage	101.00%
Payment in Kind (PIK) Note | 10% Secured PIK Notes due 2024 | Debt Instrument, Redemption, Period Three
Debt Instrument [Line Items]
Redemption price, percentage	100.00%
Payment in Kind (PIK) Note | 10% Secured PIK Notes due 2024 | Debt Instrument, Redemption, Period Four
Debt Instrument [Line Items]
Redemption price, percentage	101.00%
Term Loan | Line of Credit
Debt Instrument [Line Items]
Principal amount		$ 50,000,000
Term Loan | Line of Credit | Exit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 50,000,000
Principal amount		$ 50,000,000	$ 0
Covenant compliance, present value of estimated future net revenues, discount percent	10.00%
Ratio of present value of estimated future net revenues to sum of outstanding term loans and commitments	1.5
Term Loan | Line of Credit | Exit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Stated interest rate	7.50%
Term Loan | Line of Credit | Exit Facility | Base Rate
Debt Instrument [Line Items]
Stated interest rate	6.50%