Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (51,903,000)	$ (86,975,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Payment-in-kind interest on promissory notes	(32,822,000)
Interest expense on promissory notes	4,712,000	4,488,000
Stock-based compensation expense	6,203,000	6,857,000
Gain on foreign currency translation	(1,913,000)	(4,468,000)
(Gain) loss on extinguishment of debt	(3,529,000)	765,000
Amortization of right-of-use assets	1,182,000
Depreciation, amortization and accretion	972,000	2,857,000
Loss on warrant transactions	868,000
Gain on sale, abandonment/disposal or impairment of property and equipment		(114,000)
Write-off of inventory	0	2,212,000
Other, net	107,000	(35,000)
Changes in operating assets and liabilities:
Accounts receivable, net	504,000	(1,339,000)
Inventory	(558,000)	(3,152,000)
Prepaid expenses and other current assets	(333,000)	454,000
Other assets	(549,000)	200,000
Accounts payable	(593,000)	(1,605,000)
Accrued expenses and other current liabilities	3,498,000	2,249,000
Deferred revenue	(6,717,000)	46,814,000
Recognized loss on purchase commitments	(4,395,000)	(6,939,000)
Operating lease liabilities	(1,672,000)
Accrued interest on Mann Group promissory notes	(1,545,000)
Net cash used in operating activities	(88,483,000)	(37,731,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of treasury bills	(44,971,000)
Proceeds from sale of treasury bills	24,993,000
Purchase of property and equipment	(2,565,000)	(354,000)
Proceeds from sale of property and equipment		120,000
Purchase of limited liability company ownership interest	(300,000)
Net cash used in investing activities	(22,843,000)	(234,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from promissory notes	70,051,000
Proceeds from MidCap Credit Facility	40,000,000
Proceeds from senior convertible notes	9,910,000
Principal payments on Mann Group promissory notes	(38,264,000)
Principal payments on senior convertible notes	(11,081,000)
Principal payments on facility financing obligation	(6,920,000)	(5,000,000)
Issuance of common stock from the exercise of warrants	5,900,000
Proceeds from public offering		40,000,000
Milestone payment	(1,643,000)
Issuance cost associated with MidCap Credit Facility	(886,000)
Issuance cost associated with Mann Group promissory notes	(33,000)
Repurchase of warrants	(433,000)
Exercise of stock options	124,000
Proceeds from direct placement		28,000,000
Proceeds from market price stock purchase plan		430,000
Issuance cost associated with direct placement		(1,610,000)
Other		7,000
Net cash provided by financing activities	69,864,000	61,294,000
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS AND RESTRICTED CASH	(41,462,000)	23,329,000
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD	71,684,000	48,355,000
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD	30,222,000	71,684,000
SUPPLEMENTAL CASH FLOWS DISCLOSURES:
Interest paid in cash, net of amounts capitalized	1,757,000	3,759,000
Income taxes paid in cash		240,000
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Payment on promissory notes through issuance of common stock	8,000,000	8,160,000
Addition of right-of-use assets upon adoption of new lease guidance	5,192,000
Payment of facility obligation through common stock issuance	4,575,000	37,912,000
Payment of senior convertible notes through common stock issuance	4,500,000	5,000,000
Payment of interest on senior convertible notes through common stock issuance	1,075,000
Common stock issuance to settle employee stock purchase plan liability	656,000
Issuance of warrants associated with MidCap Credit Facility	1,854,000
Public Offering
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance costs		(2,538,000)
At The Market Issuance
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from public offering	3,199,000	2,089,000
Issuance costs	$ (60,000)	$ (84,000)