CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Noncontrolling Interests
Balance at Dec. 31, 2020	$ 103,806	$ 168	$ 1,012,932	$ 674	$ (909,968)
Balance (in shares) at Dec. 31, 2020		168,170
Issuance of common stock from exercise of stock options, vesting of restricted stock units, and ESPP purchases	1,171		1,171
Issuance of common stock from exercise of stock options, vesting of restricted stock units, and ESPP purchases (in shares)		2,621
Stock-based compensation	5,333		5,333
Other comprehensive loss	(218)			(218)
Net loss	(17,457)				(17,457)
Balance at Mar. 31, 2021	92,635	$ 168	1,019,436	456	(927,425)
Balance (in shares) at Mar. 31, 2021		170,791
Balance at Dec. 31, 2021	85,617	$ 174	1,048,936	(149)	(964,342)	$ 998
Balance (in shares) at Dec. 31, 2021		173,670
Issuance of common stock from exercise of stock options, vesting of restricted stock units, and ESPP purchases	2,138	$ 3	2,135
Issuance of common stock from exercise of stock options, vesting of restricted stock units, and ESPP purchases (in shares)		3,134
Stock-based compensation	6,426		6,426
Other comprehensive loss	(1,486)			(1,486)
Net loss	(12,284)				(12,284)
Balance at Mar. 31, 2022	$ 80,411	$ 177	$ 1,057,497	$ (1,635)	$ (976,626)	$ 998
Balance (in shares) at Mar. 31, 2022		176,804