Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 297,851	$ 14,716
Operating lease liabilities	29,870	5,680
Research and development credits	29,046	3,146
Convertible debt transactions	15,184	0
Stock-based compensation	9,895	1,734
Investment in partnerships	1,020	896
Accruals and reserves	6,908	525
Servicing rights	0	416
Amortization	111	127
Other	573	75
Total deferred tax assets	390,458	27,315
Less: valuation allowance	(351,542)	(21,241)
Deferred tax assets – net of valuation allowance	38,916	6,074
Deferred tax liabilities:
Right of use asset	28,606	5,351
Depreciation	2,123	723
Servicing rights	2,859
Intangible assets	5,911	0
Total deferred tax liabilities	39,499	6,074
Net deferred tax liabilities	$ (583)	$ 0