Consolidated Statement of Changes in Shareholders' Equity (USD $) In Thousands, except Share data	Total USD ($)	Common Stock Common Class A USD ($)	Common Stock Common Class B	Additional Paid-In Capital USD ($)	Accumulated Deficit USD ($)
Beginning balance at Dec. 31, 2010	$ 31,570	$ 1		$ 60,726	$ (29,157)
Beginning balance (in shares) at Dec. 31, 2010		16,157,339	2,153,293
Issuance of common stock and other equity changes related to compensation (in shares)		29,408
Issuance of common stock and other equity changes related to compensation	533			533
Issuance of common stock and stock options related to an acquisition (in shares)		8,700,000
Issuance of common stock and stock options related to an acquisition	21,673	2		21,671
Repurchase of common stock, Shares		(379,400)
Repurchase of common stock	(1,070)			(1,070)
Conversion of Class B common stock to Class A common stock (in shares)		2,153,293	(2,153,293)
Net loss	(1,900)				(1,900)
Ending balance at Dec. 31, 2011	50,806	3		81,860	(31,057)
Ending balance (in shares) at Dec. 31, 2011		26,660,640
Issuance of common stock and other equity changes related to compensation (in shares)		33,056
Issuance of common stock and other equity changes related to compensation	325			325
Net loss	(47,206)				(47,206)
Ending balance at Dec. 31, 2012	3,925	3		82,185	(78,263)
Ending balance (in shares) at Dec. 31, 2012		26,693,696
Issuance of common stock and other equity changes related to compensation (in shares)		132,267
Issuance of common stock and other equity changes related to compensation	509			509
Establishment of liability related to common stock warrant	(17,597)			(17,597)
Issuance of common stock related to equity funding, net of offering costs of $2,485 (in shares)		9,266,974
Issuance of common stock related to equity funding, net of offering costs of $2,485	26,834	1		26,833
Issuance of common stock related to the exercise of warrants, shares		260,791
Issuance of common stock related to the exercise of warrants	500			500
Issuance of warrants to Silicon Valley Bank	278			278
Issuance of common stock related to related party debt conversion, shares		62,111
Issuance of common stock related to related party debt conversion	100			100
Net loss	(11,300)				(11,300)
Ending balance at Dec. 31, 2013	$ 3,249	$ 4		$ 92,808	$ (89,563)
Ending balance (in shares) at Dec. 31, 2013		36,415,839