CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net loss	$ (159,576)	$ (163,357)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,936	1,839
Loss on disposal of property and equipment	87	0
Interest on non-recourse debt	27,469	20,373
Amortization of debt issuance costs	8	25
Non-cash lease expense	142	130
Non-cash expense related to stock-based compensation	11,098	4,147
Changes in inventory	(20,807)	0
Changes in accounts receivable, net	(21,963)	0
Changes in deferred revenue	61,210	65,000
Changes in other operating assets and liabilities	(2,298)	4,670
Net cash used in operating activities	(102,694)	(67,173)
Cash flows from investing activities
Purchases of property and equipment	(1,324)	(5,699)
Net cash used in investing activities	(1,324)	(5,699)
Cash flows from financing activities:
Exercise of stock options, net	1,995	2,106
Proceeds from issuance of common stock	464,593	5,829
Net cash provided by financing activities	466,588	7,935
Effect of changes in exchange rates on cash, cash equivalents and restricted cash	(5)	(14)
Net increase (decrease) in cash, cash equivalents and restricted cash	362,565	(64,951)
Cash, cash equivalents and restricted cash beginning of period	612,041	494,173
Cash, cash equivalents and restricted cash end of period	974,606	429,222
Supplemental disclosure of cash flow information:
Interest paid	169	169
Schedule for non-cash investing and financing activities:
Issuance of common stock due to debt conversion	7,114	0
Accrued capital expenditures	1,690	404
Shares received in cashless exercise	0	1,271
Total cash, cash equivalents and restricted cash	974,606	429,222
Non-cash lease expense	142	130
Change in operating lease liabilities	$ 164	$ 79