Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities
Net loss	$ (49,129)	$ (47,951)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	1,591	564
Amortization and accretion	6,585	2,105
Stock-based compensation	10,529	12,620
Other non-cash	(39)	(186)
Changes in operating assets and liabilities
Accounts receivable, net	(4,587)	(12,043)
Inventory	1,048	33
Prepaid, current and other assets	(2,410)	(1,391)
Accounts payable, accrued expenses and other current liabilities	(3,952)	(1,267)
Operating lease liabilities	(1,458)	(1,123)
Net cash used in operating activities	(41,822)	(48,639)
Cash flows from investing activities
Purchase of available-for-sale investments	(15,834)	0
Proceeds from sales and maturities of investments	50,557	0
Purchase of property, plant and equipment	(1,240)	(4,939)
Net cash provided by (used in) investing activities	33,483	(4,939)
Cash flows from financing activities
Payments related to issuance of stock for stock-based compensation arrangements, net	(1,422)	(599)
Proceeds from exercise of warrants	0	375
Other financing	0	(148)
Net cash used in financing activities	(1,422)	(372)
Net change in cash and cash equivalents	(9,761)	(53,950)
Cash and cash equivalents, at beginning of period	143,940	202,818
Cash and cash equivalents, at end of period	134,179	148,868
Non-cash investing and financing activities
Purchase of property, plant and equipment	$ 254	$ 1,608