Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities
Net loss	$ (95,115)	$ (95,723)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	2,059	1,081
Amortization and accretion	5,051	200
Stock-based compensation	23,315	19,037
Other non-cash	(155)	(165)
Changes in operating assets and liabilities
Accounts receivable, net	(22,936)	(1,125)
Inventory	(14)	(5,546)
Prepaid, current and other assets	(3,572)	1,438
Accounts payable, accrued expenses and other current liabilities	8,567	3,004
Operating lease liabilities	(2,309)	0
Net cash used in operating activities	(85,109)	(77,799)
Cash flows from investing activities
Purchase of available-for-sale investments	0	(56,195)
Proceeds from sales and maturities of investments	0	92,827
Purchase of property, plant and equipment	(7,118)	(23,032)
Net cash (used in) provided by investing activities	(7,118)	13,600
Cash flows from financing activities
Proceeds from sale of common stock, net	0	135,972
Payments related to issuance of stock for stock-based compensation arrangements, net	(968)	1,693
Payment of debt issuance costs	(396)	0
Proceeds from exercise of warrants	375	0
Other financing	(239)	(387)
Net cash (used in) provided by financing activities	(1,228)	137,278
Net change in cash and cash equivalents	(93,455)	73,079
Cash and cash equivalents, at beginning of period	202,818	197,569
Cash and cash equivalents, at end of period	109,363	270,648
Non-cash investing activities
Purchases of property, plant and equipment	$ 917	$ 5,168