CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net loss	$ (278,017)	$ (236,455)	$ (215,524)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	6,798	6,441	4,481
Amortization and accretion income, net	(1,079)	(3,451)	(1,315)
Share-based compensation	62,976	60,450	51,313
Net gain from the sale of VIBATIV business			(6,056)
Amortization of right-of-use assets	3,344	3,224
Undistributed earnings from TRC, LLC	(37,975)	(23,152)	(5,152)
Interest shortfall on 2035 notes, net	17,643
Loss on extinguishment of debt	15,464
Other	(95)	146	(43)
Changes in operating assets and liabilities:
Accounts receivable		620	1,633
Receivables from collaborative and licensing arrangements	6,128	(11,943)	(2,944)
Prepaid clinical and development services	(17,638)	(561)	(2,175)
Other prepaid and current assets	(2,327)	(73)	(225)
Inventory			(1,629)
Tax receivable	(258)	(3,700)	8,191
Other assets	(852)	(358)	45
Accounts payable	3,658	(4,274)	3,575
Accrued personnel-related expenses, accrued clinical and development expenses, and other accrued liabilities	5,983	10,626	(12,357)
Accrued interest payable	(1,685)	2,573	1,841
Deferred rent			4,308
Deferred revenue	(26,465)	(31,245)	69,224
Operating lease liabilities	1,600	(2,317)
Other long-term liabilities	(7,606)	(4,748)	(10,058)
Net cash used in operating activities	(250,403)	(238,197)	(112,867)
Investing activities
Purchases of property and equipment	(6,616)	(3,176)	(7,240)
Purchases of marketable securities	(401,987)	(423,898)	(183,261)
Maturities of marketable securities	399,318	339,018	347,192
Proceeds from the sale of marketable securities	19,942
Proceeds from the sale of property and equipment	64	5	17
Proceeds from the sale of VIBATIV business, net		5,000	20,000
Net cash provided by (used in) investing activities	10,721	(83,051)	176,708
Financing activities
Proceeds from the sale of ordinary shares, net	139,915
Proceeds from issuance of 2035 notes, net	380,000
Payment of issuance costs on 2035 notes	(5,326)
Proceeds from issuance of 2033 notes, net			229,441
Payment of redemption premium on 2033 notes	(11,470)
Principal payment on 2033 notes	(235,347)	(2,152)
Proceeds from ESPP purchases	3,701	3,474	4,173
Proceeds from option exercises	1,361	3,142	1,393
Repurchase of shares to satisfy tax withholding	(9,749)	(3,173)	(9,807)
Net cash provided by financing activities	263,085	1,291	225,200
Net increase (decrease) in cash, cash equivalents, and restricted cash	23,403	(319,957)	289,041
Cash, cash equivalents, and restricted cash at beginning of period	58,897	378,854	89,813
Cash, cash equivalents, and restricted cash at end of period	82,300	58,897	378,854
Supplemental disclosure of cash flow information
Cash paid for interest	24,024	26,178	7,475
Cash paid (received) for income taxes, net	$ 14	22	$ (7,316)
Right-of-use assets obtained in exchange for lease obligations (1)		$ 49,847