CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Unaudited) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Balance at Dec. 31, 2019	$ (488,537)	$ 447,747	$ 0	$ 4	$ 403,046	$ (891,633)	$ 46	$ 0
Balance (in shares) at Dec. 31, 2019		139,444,346	0	88,279,119
Stock issuance for exercise of stock options, net of early exercise liability	155	$ 0	$ 0	$ 0	155	0	0	0
Stock issuance for exercise of stock options, net of early exercise liability, shares		0	0	74,587
Stock-based compensation	1,977	$ 0	$ 0	$ 0	1,977	0	0	0
Unrealized holdings gain on investment securities, available-for-sale	1,723	0	0	0	0	0	1,723	0
Beneficial conversion feature	0	0	0	0	0	0	0	0
Interests issued	3,903	0	0	0	0	0	0	3,903
Net loss	(28,162)	0	0	0	0	(28,162)	0	0
Balance at Mar. 31, 2020	(508,941)	$ 447,747	$ 0	$ 4	405,178	(919,795)	1,769	3,903
Balance (in shares) at Mar. 31, 2020		139,444,346	0	88,353,707
Balance at Dec. 31, 2020	(613,193)	$ 447,747	$ 0	$ 4	411,872	(1,028,982)	10	3,903
Balance (in shares) at Dec. 31, 2020		139,444,346	0	89,206,266
Stock issuance for exercise of stock options, net of early exercise liability	1,282	$ 0	$ 0	$ 0	1,282	0	0	0
Stock issuance for exercise of stock options, net of early exercise liability, shares		0	761,480	0
Stock-based compensation	42,713	$ 0	$ 0	$ 0	42,713	0	0	0
Unrealized holdings gain on investment securities, available-for-sale	493	0	0	0		0	493	0
Preferred stock conversion	447,747	$ (447,747)	$ 0	$ 14	447,733	0	0	0
Preferred stock conversion, shares		(139,444,346)	0	139,444,346
Common stock issued related to warrants exercised	97,782			$ 1	97,781	0	0
Common stock issued related to warrants exercised, shares				7,205,490
Convertible debt conversion and other issuances	16,059			$ 7	16,052	0	0	0
Convertible debt conversion and other issuances, shares				75,084,703
Issuance of Common Stock in connection with Business Combination and PIPE offering	666,242		$ 15	$ 0	666,227	0	0	0
Issuance of Common Stock in connection with Business Combination and PIPE offering, shares			146,373,904	(49,975,104)
Conversion from Class B Common Stock to Class A Common Stock			1,143,863	(1,143,863)
Capital Contribution for Extinguishment of Debt	126,795				126,795
Acquisition of Public and Private Placement Warrants	(147,582)				(147,582)
Net loss	(48,417)	$ 0	$ 0	$ 0	0	(48,417)	0	0
Balance at Mar. 31, 2021	$ 588,935	$ 0	$ 15	$ 26	$ 1,662,873	$ (1,077,399)	$ (483)	$ 3,903
Balance (in shares) at Mar. 31, 2021		0	148,279,247	259,821,838