Preferred Stock and Common Stock Warrants - Preferred Stock (Details)		1 Months Ended		12 Months Ended
	Jan. 15, 2019 USD ($)	Sep. 30, 2018 USD ($) $ / shares shares	Aug. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 shares
York
Stockholders’ Equity
Number of directors appointed to Board			3
Valinor
Stockholders’ Equity
Number of directors appointed to Board			2
Bardin Hill
Stockholders’ Equity
Number of directors appointed to Board			1
Common Stock
Stockholders’ Equity
Issuance of stock (in shares) | shares				414,000	1,026,000
Common Stock | Backstop Agreements
Stockholders’ Equity
Issuance of stock (in shares) | shares			413,658
Convertible Preferred Stock
Stockholders’ Equity
Temporary equity, issued value per share				1,000
Conversion Price				$ 7.50
Number of trading days for conversion				60 days
Number of consecutive trading days for conversion				90 days
Minimum percentage of conversion price				175.00%
Number of business days following FID event				10 days
Dividends, temporary equity percentage				12.00%
Paid-in-kind dividends | $	$ 2,500,000			$ 700,000
Series A Convertible Preferred stock
Stockholders’ Equity
Number of shares issued | shares			50,000
Convertible preferred stock, par value			$ 0.0001
Temporary equity, issued value per share			1,000.00
Aggregate purchase price | $			$ 50,000,000	38,549,000
Additional shares issued as origination fees | $			$ 1,000
Series B Convertible Preferred stock
Stockholders’ Equity
Number of shares issued | shares		29,055
Convertible preferred stock, par value		$ 0.0001
Temporary equity, issued value per share		1,000.00
Aggregate purchase price | $		$ 29,055,000		$ 26,159,000
Additional shares issued as origination fees | $		$ 581