Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Flows from Operating Activities:
Net loss	$ (102,115)	$ (41,818)
Reconciliation of net loss to net cash used in operating activities:
Depreciation and amortization	1,566	786
Amortization of debt discount	4,598	4,265
Amortization of debt issuance costs	341	326
(Accretion) amortization of discounts/premiums on investments, net	(290)	512
Share-based compensation expense	15,764	19,879
Change in fair value of investment in restricted equity securities	(1,680)	0
Other	116	(229)
Change in operating assets and liabilities:
Accounts receivable	(15,724)	(13,497)
Inventory	(1,753)	(309)
Other current assets	(2,110)	(441)
Accounts payable and accrued liabilities	(16,567)	(7,870)
Other liabilities	5,363	(90)
Net cash used in operating activities	(112,491)	(38,486)
Cash Flows from Investing Activities:
Purchases of investments	(116,307)	(139,354)
Sales and maturities of investments	215,936	84,086
Investment in equity securities	(54,720)	0
Purchases of property and equipment	(3,939)	(1,800)
Proceeds from sales of property and equipment	4	18
Net cash provided by (used in) investing activities	40,974	(57,050)
Cash Flows from Financing Activities:
Issuance of common stock	2,581	16,135
Net cash provided by financing activities	2,581	16,135
Change in cash and cash equivalents and restricted cash	(68,936)	(79,401)
Cash and cash equivalents and restricted cash at beginning of the period	147,191	259,212
Cash and cash equivalents and restricted cash at end of the period	78,255	179,811
Supplemental Disclosure:
Non-cash capital expenditures	$ 615	$ 0