Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adopting ASC 606	$ (115,433)
Beginning Balance (in shares) at Dec. 31, 2017		49,876,000
Beginning Balance (Scenario, Previously Reported [Member]) at Dec. 31, 2017	311,012			$ (111,939)
Beginning Balance (Restatement Adjustment [Member])	(3,494)			(3,494)
Beginning Balance at Dec. 31, 2017	307,518	$ 50	$ 422,901	(115,433)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (14,792)			(14,792)
Option exercise, net (in shares)	28,036	28,000
Option exercise, net	$ 155	$ 0	155
Share-based compensation (in shares)		(23,000)
Share-based compensation	2,249	$ 0	2,249
Settlement of capped call transactions	2,118		2,118
Ending Balance (in shares) at Jun. 30, 2018		49,881,000
Ending Balance at Jun. 30, 2018	296,252	$ 50	427,423	(131,221)
Beginning Balance (Restatement Adjustment [Member])				3,800
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(11,394)
Ending Balance (in shares) at Jun. 30, 2018		49,881,000
Ending Balance at Jun. 30, 2018	296,252	$ 50	$ 427,423	$ (131,221)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adopting ASC 606	$ (131,221)