Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (111,560)	$ (162,044)	$ (120,692)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	6,662	6,288	6,006
Share-based compensation	9,892	7,625	12,429
Non-cash royalty revenue	(30,424)	(17,309)
Non-cash interest expense	42,201	24,599	18,242
Loss on disposal of assets	58	145	24
Change in fair value of contingent obligations	5,805	(1,335)	(3,188)
Gain on issuance of stock for settlement of milestone obligation			(566)
Loss on extinguishment of debt		10,767
Changes in operating assets and liabilities:
Accounts receivable	(15,355)	196	10,217
Inventories	55	24	9
Prepaid expenses	11,792	(8,210)	(8,453)
Accounts payable	(234)	5,366	1,646
Deferred revenue	53,900	(397)	(2,722)
Accrued liabilities and other current liabilities	7,097	3,303	(4,849)
Other operating assets and liabilities	1,429	(113)	(2,329)
Net cash used in operating activities	(18,682)	(131,095)	(94,226)
Cash flows from investing activities:
Proceeds from sale of plant and equipment		6	120
Purchases of plant and equipment	(4,657)	(3,597)	(3,120)
Purchases of available-for-sale securities			(14,936)
Proceeds from sale of available-for-sale securities			20,000
Net cash provided by (used in) investing activities	(4,657)	(3,591)	2,064
Cash flows from financing activities:
Net proceeds from sale of equity	30,000	44,919	65,560
Proceeds from employee stock purchases and option exercises	1,643	1,234	987
Purchase of treasury shares to satisfy tax withholdings			(527)
Proceeds from issuance of long-term debt			15,000
Debt issuance costs			(150)
Proceeds from sale of future royalties		204,878
Transaction costs from sale of future royalties and milestones		(494)
Repayments of debt		(161,847)
Payment of finance lease obligation	(320)	(283)	(331)
Net cash provided by (used in) financing activities	31,323	128,286	80,539
Effect of exchange rate changes on cash	770	(733)	362
Net decrease in cash and cash equivalents	8,754	(7,133)	(11,261)
Cash and cash equivalents, beginning of period	53,054	60,187	71,448
Cash and cash equivalents, end of period	61,808	53,054	60,187
Supplemental cash flow information:
Cash paid for interest	1,224	1,171	1,120
Supplemental disclosures - non-cash activities:
Purchases of plant and equipment in accounts payable and accrued liabilities	1,242	300	968
Lease right-of-use assets obtained in exchange for new operating lease liabilities	3,017
Milestone obligation [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock			1,486
Payment to Consultant [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock	$ 81	50
SECANT Yeast Display technology [Member]
Supplemental disclosures - non-cash activities:
Issuance of common stock			$ 3,548
Series C-1 Convertible Preferred Stock [Member]
Cash flows from financing activities:
Net proceeds from sale of C-1 Preferred Stock		$ 39,879