Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating activities
Net loss	$ (67,180)	$ (36,439)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	1,637	2,003
Stock-based compensation	6,406	4,196
Amortization of debt discount and issuance costs	1,507	0
Non-cash lease expense	1,216
Change in assets and liabilities
Accrued revenue	(890)	1,241
Inventory	(15,612)	(3,286)
Other assets	1,441	3,374
Accounts payable	14,848	1,029
Accrued liabilities	21,695	7,248
Operating lease liabilities	(1,459)
Deferred rent	69	(268)
Origination of loans held for sale	(49,850)	(9,477)
Proceeds from sale of loans originated as held for sale	39,015	9,887
Net cash used in operating activities	(47,157)	(20,492)
Investing activities
Purchases of property and equipment	(3,151)	(2,305)
Net cash used in investing activities	(3,151)	(2,305)
Financing activities
Proceeds from the exercise of stock options	3,732	5,946
Tax payment related to net share settlements on restricted stock units	(818)	(59)
Borrowings from warehouse credit facilities	48,557	9,265
Repayments of warehouse credit facilities	(38,097)	(9,924)
Other payables - deposits held in escrow	3,968	6,808
Net cash provided by financing activities	17,342	12,036
Net change in cash, cash equivalents, and restricted cash	(32,966)	(10,761)
Cash, cash equivalents, and restricted cash
Beginning of period	439,055	212,658
End of period	406,089	201,897
Supplemental disclosure of cash flow information
Cash paid for interest	1,202	0
Non-cash transactions
Stock-based compensation capitalized in property and equipment	(270)	(124)
Property and equipment additions in accounts payable and accrued liabilities	(1,370)	(55)
Leasehold improvements paid directly by lessor	$ 1,963	$ 0