Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating activities
Net loss	$ (205,451)	$ (266,659)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of debt discount and deferred financing	1,124	2,290
Depreciation and amortization	6,299	3,261
Stock-based compensation	36,912	31,522
Loss on exchange of convertible debt	0	40,624
Loss on extinguishment of debt	7,276	0
Non-cash changes in the fair value of contingent consideration payable	2,680	2,652
Foreign currency remeasurement loss	(1,084)	2,665
Other	0	(136)
Changes in operating assets and liabilities:
Accounts receivable	(10,845)	(12,644)
Inventories	2,182	(2,016)
Prepaid expenses and other current assets	4,377	(3,321)
Accounts payable and accrued expenses	(23,424)	8,714
Other non-current assets and liabilities	(2,264)	1,964
Deferred reimbursements	(1,250)	(1,500)
Net cash used in operating activities	(183,468)	(192,584)
Investing activities
Sale and redemption of marketable securities	272,679	389,242
Purchases of marketable securities	(261,322)	(311,965)
Capital expenditures	(2,160)	(9,087)
Net cash provided by investing activities	9,197	68,190
Financing activities
Proceeds from issuance of common stock, net of issuance costs	0	188,994
Payment of long-term debt	(155,249)	0
Proceeds from long-term debt, net of issuance costs	385,929	0
Payment of finance leases	(58)	(177)
Purchase of vested restricted stock units	(9,340)	(3,001)
Proceeds from termination of capped call confirmations	0	19,875
Proceeds from exercise of stock options	20,028	7,808
Proceeds of exercise of warrants	0	812
Net cash provided by financing activities	241,310	214,311
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	45	(2,591)
Net increase in cash, cash equivalents, and restricted cash at the end of the period	67,084	87,326
Cash, cash equivalents, and restricted cash at beginning of period	146,341	82,375
Cash, cash equivalents, and restricted cash at the end of period	213,425	169,701
Supplemental disclosures of cash flow information
Tenant improvements paid through lease incentives	470	14,875
Cash paid during the period for interest	16,712	13,145
Contingent consideration paid in shares	0	9,316
Capital expenditures unpaid at the end of period	$ 265	$ 2,802