Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net loss	$ (90,806)	$ (35,784)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	14,813	4,341
Stock-based compensation	16,788	12,583
Amortization of debt discount and issuance costs	1,440	855
Non-cash lease expense	3,169	2,533
Net loss (gain) on IRLCs, forward sales commitments, and loans held for sale	60	(1,052)
Other	2,290	109
Change in assets and liabilities:
Accounts receivable, net	17,312	7,303
Inventory	112,734	(48,213)
Prepaid expenses and other assets	(1,982)	(3,359)
Accounts payable	9,876	5,947
Accrued and other liabilities, deferred tax liabilities, and payroll tax liabilities, noncurrent	(14,442)	8,873
Lease liabilities	(3,642)	(2,951)
Origination of loans held for sale	(159,186)	(227,090)
Proceeds from sale of loans originated as held for sale	170,577	225,140
Net cash provided by (used in) operating activities	79,001	(50,765)
Investing activities
Purchases of property and equipment	(7,442)	(5,285)
Purchases of investments	(77,596)	(67,877)
Sales of investments	5,346	0
Maturities of investments	6,500	63,589
Net cash used in investing activities	(73,192)	(9,573)
Financing activities
Proceeds from the issuance of common stock pursuant to employee equity plans	1,887	3,411
Tax payments related to net share settlements on restricted stock units	(2,595)	(10,860)
Borrowings from warehouse credit facilities	152,386	216,382
Repayments to warehouse credit facilities	(163,144)	(214,747)
Borrowings from secured revolving credit facility	156,799	71,177
Repayments to secured revolving credit facility	(219,711)	(46,275)
Proceeds from issuance of convertible senior notes, net of issuance costs	0	488,691
Purchases of capped calls related to convertible senior notes	0	(54,480)
Payments for repurchases and conversions of convertible senior notes	0	(1,886)
Other financing payables	0	6,521
Principal payments under finance lease obligations	(217)	(67)
Cash paid for secured revolving credit facility issuance costs	(764)	(305)
Net cash (used in) provided by financing activities	(75,359)	457,562
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(4)	1
Net change in cash, cash equivalents, and restricted cash	(69,554)	397,225
Cash, cash equivalents, and restricted cash:
Beginning of period	718,281	945,820
End of period	648,727	1,343,045
Supplemental disclosure of cash flow information
Cash paid for interest	3,377	973
Non-cash transactions
Stock-based compensation capitalized in property and equipment	1,134	732
Property and equipment additions in accounts payable and accrued liabilities	326	2,348
Leasehold improvements paid directly by lessor	$ 0	$ 1,334