CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Convertible debt	Common Stock	Additional Paid-In Capital	Additional Paid-In Capital Convertible debt	Accumulated Earnings (Deficit)	Accumulated Other Comprehensive Loss
Balances (in shares) at Dec. 31, 2018			64,185
Balances at Dec. 31, 2018	$ 220,335		$ 6	$ 402,934		$ (182,600)	$ (5)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of options (in shares)			14
Issuance of common stock upon exercise of options	25			25
Issuance of common stock in conjunction with vesting of restricted stock units (in shares)			132
Stock-based compensation	2,702			2,702
Shares withheld for payment of employee's withholding tax liability	(216)			(216)
Net income (loss)	(14,301)					(14,301)
Balances (in shares) at Mar. 31, 2019			64,331
Balances at Mar. 31, 2019	208,545		$ 6	405,445		(196,901)	(5)
Balances (in shares) at Dec. 31, 2019			80,888
Balances at Dec. 31, 2019	57,958		$ 8	457,751		(399,801)	0
Increase (Decrease) in Stockholders' Equity
Issuance of common stock in conjunction with vesting of restricted stock units (in shares)			434
Reacquisition of equity component of 2021 Notes and 2024 Notes		$ (16,814)			$ (16,814)
Stock-based compensation	1,934			1,934
Shares withheld for payment of employee's withholding tax liability	(271)			(271)
Net income (loss)	41,230					41,230
Balances (in shares) at Mar. 31, 2020			81,322
Balances at Mar. 31, 2020	$ 84,037		$ 8	$ 442,600		$ (358,571)	$ 0