CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 118,016	$ 159,180
Short-term marketable securities	32,417	28,103
Related party receivables from collaborative arrangements	46,847	26,228
Prepaid expenses and other current assets	766	814
Total current assets	198,046	214,325
Property and equipment, net	368	221
Capitalized fees paid to a related party, net	180,545	194,368
Other assets	37	18
Total assets	378,996	408,932
Current liabilities:
Accounts payable	128	818
Accrued personnel-related expenses	2,361	1,659
Accrued interest payable	7,828	7,911
Other accrued liabilities	1,095	2,218
Non-recourse notes, due 2029, current	7,752	0
Deferred revenue	885	885
Total current liabilities	20,049	13,491
Convertible subordinated notes, due 2023, net of issuance costs	237,597	250,992
Non-recourse notes, due 2029, net of issuance costs	470,744	482,139
Other long-term liabilities	1,383	1,856
Deferred revenue	2,214	3,099
Commitments and contingencies (Notes 9)
Stockholders' Deficit:
Preferred stock: $0.01 par value, 230 shares authorized, no shares issued and outstanding
Common stock: $0.01 par value, 200,000 shares authorized, 108,585 and 114,933 shares issued as of December 31, 2016 and 2015, respectively	1,085	1,149
Treasury stock: 150 shares at December 31, 2016 and 2015	(3,263)	(3,263)
Additional paid-in capital	1,282,077	1,351,898
Accumulated other comprehensive income (loss)	1	(2)
Accumulated deficit	(1,632,891)	(1,692,427)
Total stockholders' deficit	(352,991)	(342,645)
Total liabilities and stockholders' deficit	$ 378,996	$ 408,932