Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Additional paid in capital	Treasury stock	Accumulated deficit
Balance at beginning of period (in shares) at Dec. 31, 2017		46,827,762
Balance at beginning of the period at Dec. 31, 2017	$ 842,766	$ 468	$ 961,200	$ 0	$ (118,902)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	5,581		5,581
Restricted stock forfeited (in shares)		(83,770)
Restricted stock forfeited	(1)	$ (1)
Repurchase of common stock (in shares)		(63,919)
Repurchase of common stock	(1,422)			(1,422)
Net loss	(11,442)				(11,442)
Balance at end of period (in shares) at Mar. 31, 2018		46,680,073
Balance at end of the period at Mar. 31, 2018	835,482	$ 467	966,781	(1,422)	(130,344)
Balance at beginning of period (in shares) at Dec. 31, 2017		46,827,762
Balance at beginning of the period at Dec. 31, 2017	$ 842,766	$ 468	961,200	0	(118,902)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock (in shares)	(256,895)
Net loss	$ (45,503)
Balance at end of period (in shares) at Sep. 30, 2018		46,460,414
Balance at end of the period at Sep. 30, 2018	803,419	$ 467	972,229	(4,872)	(164,405)
Balance at beginning of period (in shares) at Mar. 31, 2018		46,680,073
Balance at beginning of the period at Mar. 31, 2018	835,482	$ 467	966,781	(1,422)	(130,344)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)		55,000
Stock-based compensation	2,336		2,336
Restricted stock forfeited (in shares)		(81,683)
Restricted stock forfeited	0
Repurchase of common stock (in shares)		(192,976)
Repurchase of common stock	(3,450)			(3,450)
Net loss	(21,993)				(21,993)
Balance at end of period (in shares) at Jun. 30, 2018		46,460,414
Balance at end of the period at Jun. 30, 2018	812,375	$ 467	969,117	(4,872)	(152,337)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	3,112		3,112
Restricted stock forfeited	$ 0
Repurchase of common stock (in shares)	0
Repurchase of common stock	$ 0
Net loss	(12,068)				(12,068)
Balance at end of period (in shares) at Sep. 30, 2018		46,460,414
Balance at end of the period at Sep. 30, 2018	$ 803,419	$ 467	972,229	(4,872)	(164,405)
Balance at beginning of period (in shares) at Dec. 31, 2018	46,390,513	46,390,513
Balance at beginning of the period at Dec. 31, 2018	$ 884,687	$ 467	974,616	(4,936)	(85,460)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)		94,078
Stock-based compensation	1,424	$ 1	1,423
Restricted stock forfeited (in shares)		(97,113)
Restricted stock forfeited	(1)	$ (1)
Repurchase of common stock (in shares)		(80,422)
Repurchase of common stock	(463)			(463)
Net loss	(103,540)				(103,540)
Balance at end of period (in shares) at Mar. 31, 2019		46,307,056
Balance at end of the period at Mar. 31, 2019	$ 782,107	$ 467	976,039	(5,399)	(189,000)
Balance at beginning of period (in shares) at Dec. 31, 2018	46,390,513	46,390,513
Balance at beginning of the period at Dec. 31, 2018	$ 884,687	$ 467	974,616	(4,936)	(85,460)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock (in shares)	(224,542)
Net loss	$ (279,704)
Balance at end of period (in shares) at Sep. 30, 2019	46,408,285	46,408,285
Balance at end of the period at Sep. 30, 2019	$ 607,723	$ 469	978,525	(6,107)	(365,164)
Balance at beginning of period (in shares) at Mar. 31, 2019		46,307,056
Balance at beginning of the period at Mar. 31, 2019	782,107	$ 467	976,039	(5,399)	(189,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)		160,400
Stock-based compensation	1,250	$ 1	1,249
Restricted stock forfeited	0
Repurchase of common stock (in shares)		(126,231)
Repurchase of common stock	(708)			(708)
Issuance of common stock - litigation settlement (in shares)		76,217
Issuance of common stock - litigation settlement	324	$ 1	323
Net loss	(45,229)				(45,229)
Balance at end of period (in shares) at Jun. 30, 2019		46,417,442
Balance at end of the period at Jun. 30, 2019	737,744	$ 469	977,611	(6,107)	(234,229)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)		17,512
Stock-based compensation	924		924
Restricted stock forfeited (in shares)		(26,669)
Restricted stock forfeited	$ 0
Repurchase of common stock (in shares)	(17,889)
Cash settlement of stock based awards	$ (10)		(10)
Net loss	$ (130,935)				(130,935)
Balance at end of period (in shares) at Sep. 30, 2019	46,408,285	46,408,285
Balance at end of the period at Sep. 30, 2019	$ 607,723	$ 469	$ 978,525	$ (6,107)	$ (365,164)