CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total		Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Convertible Note 2023	Convertible Note 2023 Additional Paid-in Capital
Balance (in shares) at Dec. 31, 2017			53,400,281
Balance at Dec. 31, 2017	$ 44,753	[1]	$ 554	$ 106,312	$ (2,019)	$ (60,094)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	1,165			1,165
Stock options exercised	12			12
Issuance of stock for vested restricted stock units (in shares)			112,607
Fair value of conversion feature on Convertible 4.75% Senior Notes							$ 19,043	$ 19,043
Cumulative translation adjustment	(332)				(332)
Net loss	(25,518)
Balance (in shares) at Jun. 30, 2018			53,512,888
Balance at Jun. 30, 2018	$ 39,123		$ 554	$ 126,532	$ (2,351)	$ (85,612)

[1] Derived from the audited December 31, 2017 financial statement