CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Balance at period start (in shares) at Dec. 31, 2020		54,003
Balance at period start at Dec. 31, 2020	$ 246,274	$ 540	$ 726,504	$ (477,028)	$ (3,742)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock offering, net of issuance costs (in shares)		5,750
Common stock offering, net of issuance costs	87,401	$ 58	87,343
Stock-based compensation (in shares)		461
Stock-based compensation	1,886	$ 3	1,883
Purchase of common stock for retirement (in shares)		(76)
Purchase of common stock for retirement	(1,321)		(1,321)
Exercise of stock options (in shares)		4
Exercise of stock options	58		58
Other comprehensive income	3,996				3,996
Net loss	(62,227)			(62,227)
Balance at period end (in shares) at Mar. 31, 2021		60,142
Balance at period end at Mar. 31, 2021	276,067	$ 601	814,467	(539,255)	254
Balance at period start (in shares) at Dec. 31, 2021		60,162
Balance at period start at Dec. 31, 2021	265,700	$ 602	821,713	(559,117)	2,502
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)		412
Stock-based compensation	3,658	$ 3	3,655
Purchase of common stock for retirement (in shares)		(462)
Purchase of common stock for retirement	(6,390)	$ (4)	(1,431)	(4,955)
Other comprehensive income	0
Net loss	(137,051)			(137,051)
Balance at period end (in shares) at Mar. 31, 2022		60,112
Balance at period end at Mar. 31, 2022	$ 125,917	$ 601	$ 823,937	$ (701,123)	$ 2,502