CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total
Balance, beginning at Dec. 31, 2011	$ 44	$ 463,440	$ (388,674)	$ (268)	$ (2,741)	$ 71,801
Balance, beginning (in shares) at Dec. 31, 2011	34,046				(200)
Net income (loss)			(35,431)			(35,431)
Other comprehensive income				8		8
Compensation expenses for share-based payment arrangements		6,536				6,536
Acquisition of subsidiary escrow shares returned						0
Sale of common stock in public offering, net of underwriting discounts and commissions and offering expenses	17	23,331				23,348
Sale of common stock in public offering, net of underwriting discounts and commissions and offering expenses (in shares)	12,650
Forfeitures of restricted stock	0	0				0
Forfeitures of restricted stock (in shares)	(6)
Sale of common stock under employee stock purchase plans and exercise of stock options	0	306				306
Sale of common stock under employee stock purchase plans and exercise of stock options (in shares)	75
Balance, ending at Dec. 31, 2012	61	493,613	(424,105)	(260)	(2,741)	66,568
Balance, ending (in shares) at Dec. 31, 2012	46,765				(200)
Net income (loss)			(42,572)			(42,572)
Other comprehensive income				68		68
Compensation expenses for share-based payment arrangements		3,546				3,546
Acquisition of subsidiary, net of issuance costs	6	11,214				11,220
Acquisition of subsidiary, net of issuance costs - shares	4,472
Acquisition of subsidiary escrow shares returned						0
Sale of common stock in public offering, net of underwriting discounts and commissions and offering expenses	12	40,066				40,078
Sale of common stock in public offering, net of underwriting discounts and commissions and offering expenses (in shares)	9,775
Forfeitures of restricted stock	0	0				0
Forfeitures of restricted stock (in shares)	(1)
Exercise of stock options	0	71				71
Exercise of stock options (in shares)	14
Balance, ending at Dec. 31, 2013	79	548,510	(466,677)	(192)	(2,741)	78,979
Balance, ending (in shares) at Dec. 31, 2013	61,025				(200)
Net income (loss)			4,410			4,410
Other comprehensive income				192		192
Compensation expenses for share-based payment arrangements		3,523				3,523
Acquisition of subsidiary escrow shares returned	0	(82)				(82)
Acquisition of subsidiary escrow shares returned - shares	(19)
Sale of common stock in public offering, net of underwriting discounts and commissions and offering expenses	12	37,447				37,459
Sale of common stock in public offering, net of underwriting discounts and commissions and offering expenses (in shares)	8,750
Exercise of stock options	0	428				428
Exercise of stock options (in shares)	77					77
Balance, ending at Dec. 31, 2014	$ 91	$ 589,826	$ (462,267)	$ 0	$ (2,741)	$ 124,909
Balance, ending (in shares) at Dec. 31, 2014	69,833				(200)