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	$ (111,939)
Beginning Balance (in shares) at Dec. 31, 2017		49,876,000
Beginning Balance at Dec. 31, 2017	311,012	$ 50	$ 422,901	$ (111,939)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (3,127)			(3,127)
Option exercise, net (in shares)	5,500	5,000
Option exercise, net	$ 32	$ 0	32
Share-based compensation (in shares)		(14,000)
Share-based compensation	1,180	$ 0	1,180
Ending Balance (in shares) at Mar. 31, 2018		49,867,000
Ending Balance at Mar. 31, 2018	308,101	$ 50	$ 424,113	$ (116,062)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adopting ASC 606	$ (116,062)