Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities:
Net (loss) income	$ (69,707)	$ 26,144	$ 8,587
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Stock-based compensation	7,353	7,686	9,492
Depreciation	1,402	1,621	1,625
Amortization of debt issuance costs and debt discount	991	791	457
Change in fair value of warrant liabilities	(5,387)	1,103	(25,332)
Change in fair value of embedded derivatives	0	0	14
Change in fair value of contingent consideration	1,800	(2,000)	0
Impairment charges	8,431	0	838
Loss on sale of short-term investments	0	5,746	0
Loss on extinguishment of debt	0	0	1,254
Gain on sale of business	0	(89,484)	(79,980)
Changes in operating assets and liabilities:
Trade accounts receivable	(11,181)	7,477	(2,212)
Inventory	4,983	1,394	(3,503)
Prepaid expenses and other current assets	(3,394)	(650)	(9,200)
Other assets	471	316	(4,126)
Accounts payable and accrued expenses	(1,671)	(14,385)	5,404
Deferred revenue	(5,839)	(8,464)	15,658
Deferred tax liability	(1,025)	(2,050)	0
Deferred rent and other liabilities	(107)	153	208
Net cash used in operating activities	(72,880)	(64,602)	(80,816)
Investing activities:
Purchases of property and equipment	(103)	(308)	(122)
Proceeds from divestiture of businesses	0	82,984	89,624
Change in restricted cash from divestiture of businesses	10,002	(1,502)	(8,500)
Proceeds from sale of short-term investments	0	4,371	0
Acquisition of business, net of cash acquired	0	0	(20,000)
Net cash provided by investing activities	9,899	85,545	61,002
Financing activities:
Proceeds from borrowings of debt and revolving credit facility, net of issuance costs	2,167	0	27,977
Payments on borrowings of debt	(3,334)	(1,450)	(40,041)
Proceeds from issuance of common stock under employee stock plans and exercise of warrants	350	1,441	1,506
Proceeds from issuance of common stock and common stock warrants, net of issuance costs	0	92,210	556
Net cash (used in) provided by financing activities	(817)	92,201	(10,002)
Net (decrease) increase in cash and cash equivalents	(63,798)	113,144	(29,816)
Cash and cash equivalents at beginning of period	155,349	42,205	72,021
Cash and cash equivalents at end of period	91,551	155,349	42,205
Supplemental disclosure of cash flow information:
Cash paid for interest	1,470	1,466	12,847
Noncash investing and financing activities:
Issuance of common stock in connection with acquisition	0	0	15,237
Issuance of common stock in connection with cashless exercise of warrants	0	300	0
Purchase of property and equipment in accounts payable	0	0	12
Change in common stock warrant liability associated with exercise of warrants	0	0	(916)
Warrants issued in connection with debt	$ 0	$ 0	$ 558