Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income (loss)	$ 14,016	$ 19,871	$ (92,273)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Loss on extinguishment of debt	2,338	2,592	9,550
Change in fair value of derivative liability	(193)	(2,809)	13,354
Unrealized loss (gain) on marketable securities		(154)	57
Depreciation and amortization	921	928	742
Amortization of deferred financing costs and debt discount	748	2,090	3,033
Share-based compensation expense	4,231	2,716	1,913
Changes in operating assets and liabilities:
Accounts receivable	(8,638)	(12,216)	(5,043)
Inventories	854	(6,289)	(6,000)
Prepaid expenses and other assets	(1,582)	(1,144)	(889)
Accounts payable	2,061	(1,279)	336
Accrued sales deductions	18,333	7,461	1,000
Accrued expenses	(1,604)	2,854	7,156
Deferred product revenue, net		(7,882)	7,883
Deferred licensing revenue	149	(204)	803
Other non-current liabilities	489	1,198	429
Net cash provided by (used in) operating activities	32,123	7,733	(57,949)
Cash flows from investing activities
Purchases of marketable securities	(63,205)	(53,262)	(85,567)
Sales and maturities of marketable securities	37,581	53,473	75,806
Purchases of property and equipment	(2,104)	(593)	(1,646)
Deferred legal fees	(8,506)	(4,505)	(705)
Net cash used in investing activities	(36,234)	(4,887)	(12,112)
Cash flows from financing activities
Proceeds from issuance of common stock	1,867	571	2,437
Proceeds from convertible debt issuance			90,000
Cash settlement of debt to equity conversion		(1)	(1,727)
Repayment of secured notes payable			(24,344)
Financing costs and underwriters discounts			(3,627)
Net cash provided by financing activities	1,867	570	62,739
Net change in cash and cash equivalents	(2,244)	3,416	(7,322)
Cash and cash equivalents at beginning of year	36,396	32,980	40,302
Cash and cash equivalents at end of year	34,152	36,396	32,980
Supplemental cash flow information:
Cash paid for interest	825	2,854	4,313
Noncash financial activity:
Conversion of convertible notes and interest make-whole	27,089	$ 14,887	42,417
Initial value of interest make-whole derivative issued in connection with the convertible debt			9,270
Initial value of conversion option reported in equity			$ 22,336
Exercise of warrants	652
Deferred legal fees included in accrued expenses	$ 9,392