CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($)	Total	Common Stock	Additional Paid in Capital	Accumulated Deficit	Other Comprehensive (Loss) Income
Beginning balance (in shares) (Predecessor) at Dec. 31, 2014		0
Beginning balance (Predecessor) at Dec. 31, 2014	$ 45,912,000	$ 0	$ 49,186,000	$ (3,274,000)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from parent | Predecessor	1,116,000		1,116,000
Net income (loss) | Predecessor	(29,455,000)		0	(29,455,000)
Net income (loss)	(29,455,000)
Ending balance (Predecessor) at Oct. 08, 2015	17,573,000		50,302,000	(32,729,000)	0
Ending balance at Oct. 08, 2015	0		0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from parent (in shares)		$ 29,974,239,000
Capital contributions from parent	298,677,000		298,677,000
Net income (loss)	(7,926,000)			(7,926,000)
Ending balance (in shares) at Dec. 31, 2015		29,974,239,000
Ending balance at Dec. 31, 2015	290,751,000	$ 0	298,677,000	(7,926,000)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from parent	66,205,000		66,205,000
Net income (loss)	(28,370,000)			(28,370,000)
Capital distributions	(67,000)		(67,000)
Other comprehensive loss	(3,000)				(3,000)
Ending balance (in shares) at Dec. 31, 2016		29,974,239,000
Ending balance at Dec. 31, 2016	328,516,000	$ 0	364,815,000	(36,296,000)	(3,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from parent	2,997,000		2,997,000
Net income (loss)	82,480,000			82,480,000
Other comprehensive loss	2,357,000				2,357,000
Proceeds from initial public offering, net (in shares)		12,800,000,000
Proceeds from initial public offering, net	163,952,000	$ 13,000	163,939,000
Tax receivable agreement liability	(203,837,000)		(203,837,000)
Stock-based compensation (in shares)		91,168,000
Stock-based compensation	2,199,000		2,199,000
Ending balance (in shares) at Dec. 31, 2017		42,865,407,000
Ending balance at Dec. 31, 2017	$ 378,664,000	$ 13,000	$ 330,113,000	$ 46,184,000	$ 2,354,000