Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities
Net loss	$ (144,517)	$ (181,111)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	3,610	1,730
Amortization and accretion	6,335	833
Induced conversion of 2014 Convertible Notes	0	24,059
Stock-based compensation	33,921	29,015
Other non-cash	(252)	(207)
Changes in operating assets and liabilities
Accounts receivable, net	(30,563)	(1,961)
Inventory	(4,080)	(5,299)
Prepaid, current and other assets	(2,715)	955
Accounts payable, accrued expenses and other current liabilities	18,576	10,924
Operating lease liabilities	(3,621)	0
Net cash used in operating activities	(123,306)	(121,062)
Cash flows from investing activities
Purchase of available-for-sale investments	(97,268)	(56,195)
Proceeds from sales and maturities of investments	0	107,297
Purchase of property, plant and equipment	(7,911)	(29,404)
Net cash (used in) provided by investing activities	(105,179)	21,698
Cash flows from financing activities
Proceeds from convertible notes, net of issuance costs	308,349	0
Payment for capped call options	(32,890)	0
Proceeds from sale of common stock, net	0	135,972
Payments related to issuance of stock for stock-based compensation arrangements, net	(597)	2,933
Payments of debt issuance costs	(532)	(1,621)
Proceeds from exercise of warrants	375	0
Other financing	(336)	(535)
Net cash provided by financing activities	274,369	136,749
Net change in cash and cash equivalents	45,884	37,385
Cash and cash equivalents, at beginning of period	202,818	197,569
Cash and cash equivalents, at end of period	248,702	234,954
Non-cash investing and financing activities
Conversion of 2014 Convertible Notes to common stock	0	148,078
Purchase of property, plant and equipment	1,389	3,066
Debt issuance costs included in accrued expense and other current liabilities	$ 1,275	$ 0