CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (44,372)	$ (104,133)	$ (168,843)
Adjustments to reconcile net loss to net cash used for operating activities:
Non-cash royalty revenue related to sale of future royalties	(68,529)	(47,415)	(32,154)
Non-cash interest expense on liability related to sale of future royalties and convertible senior notes	23,107	16,879	10,631
Depreciation and amortization	2,101	4,028	7,411
(Gain) loss on sale/disposal of fixed assets and impairment charges	(691)	1,689	115
Operating lease right-of-use asset impairment		694
Stock and deferred share unit compensation	14,321	14,167	16,807
Deferred rent			(95)
Change in operating assets and liabilities:
Accounts receivable	7,465	(5,799)	948
Unbilled receivable	990	(384)	1,963
Inventory			1,038
Contract asset	3,631	(3,131)	(500)
Prepaid and other current assets	(2,476)	(963)	(1,495)
Operating lease right-of-use assets	1,515	1,331
Other assets	(7,202)	(75)	88
Accounts payable	(819)	(1,045)	2,667
Accrued compensation	(4,100)	(2,189)	323
Other accrued liabilities	16,734	(6,146)	3,839
Deferred revenue	(17,323)	46,630	(9,165)
Operating lease liability	(2,972)	(2,505)
Net cash used for operating activities	(78,620)	(88,367)	(166,422)
Cash flows from investing activities:
Purchases of property and equipment	(917)	(2,845)	(5,246)
Proceeds from sale of equipment	1,426	2,312
Net cash provided by (used for) investing activities	509	(533)	(5,246)
Cash flows from financing activities:
Proceeds from issuance of common stock under stock plans	1,471	2,873	4,301
Proceeds from common stock issuance, net of $701 and $395 of transaction costs, respectively	194,271		162,512
Net cash provided by financing activities	195,742	2,873	166,813
Net change in cash and cash equivalents	117,631	(86,027)	(4,855)
Cash and cash equivalents, beginning of period	176,225	262,252	267,107
Cash and cash equivalents, end of period	293,856	176,225	262,252
Supplemental cash flow information:
Cash paid during the year for interest	$ 95	$ 95	$ 95