Parent and Subsidiary Guarantor - Condensed Consolidating Statements of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues	$ (452,659)	$ (453,017)	$ (252,839)
Operating expenses	(424,092)	(319,031)	(267,539)
General and administrative	(44,759)	(45,130)	(42,476)
Merger transaction expense	(4,492)	(7,991)	(8,749)
Interest expense	(58,100)	(52,703)	(57,710)
Interest income and other income (expense)	(98,162)	94,885	(15,992)
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	(176,946)	123,047	(139,627)
(Provision for) Benefit from income taxes	42,116	(1,827)	1,402
Equity in earnings (loss) of subsidiaries	0	0	0
Net income (loss)	(134,830)	121,220	(138,225)
Reportable Legal Entities | Parent Guarantor
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues	0	0
Operating expenses	0	0
General and administrative	0	0
Merger transaction expense	0	0
Interest expense	0	0
Interest income and other income (expense)	0	0
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	0	0
(Provision for) Benefit from income taxes	0	0
Equity in earnings (loss) of subsidiaries	(134,830)	121,220
Net income (loss)	(134,830)	121,220
Reportable Legal Entities | Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues	(452,623)	(453,017)
Operating expenses	(424,090)	(319,031)
General and administrative	(44,759)	(45,130)
Merger transaction expense	(4,492)	(7,991)
Interest expense	(58,100)	(52,703)
Interest income and other income (expense)	(98,162)	94,885
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	(176,980)	123,047
(Provision for) Benefit from income taxes	42,116	(1,827)
Equity in earnings (loss) of subsidiaries	34	0
Net income (loss)	(134,830)	121,220
Reportable Legal Entities | Parent Issuer
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues			(252,257)
Operating expenses			(266,119)
General and administrative			(42,476)
Merger transaction expense			(8,749)
Interest expense			(57,710)
Interest income and other income (expense)			(15,992)
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries			(138,789)
(Provision for) Benefit from income taxes			1,402
Equity in earnings (loss) of subsidiaries			(838)
Net income (loss)			(138,225)
Reportable Legal Entities | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues	(36)		(582)
Operating expenses	(2)		(1,420)
General and administrative	0		0
Merger transaction expense	0		0
Interest expense	0		0
Interest income and other income (expense)	0		0
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	34		(838)
(Provision for) Benefit from income taxes	0		0
Equity in earnings (loss) of subsidiaries	0		0
Net income (loss)	34		(838)
Intercompany Eliminations
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues	0	0	0
Operating expenses	0	0	0
General and administrative	0	0	0
Merger transaction expense	0	0	0
Interest expense	0	0	0
Interest income and other income (expense)	0	0	0
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	0	0	0
(Provision for) Benefit from income taxes	0	0	0
Equity in earnings (loss) of subsidiaries	134,796	(121,220)	838
Net income (loss)	$ 134,796	$ (121,220)	$ 838