Annual report pursuant to Section 13 and 15(d)

Capital Structure - Warrants (Details)

Capital Structure - Warrants (Details) - USD ($) $ / shares in Units, $ in Millions	Dec. 31, 2015	Oct. 20, 2015	Aug. 31, 2014	Jul. 31, 2014	Aug. 31, 2013	Apr. 30, 2012	Mar. 23, 2012
Series B convertible preferred stock
Warrants
Face amount				$ 1.0
Common Stock [Member]
Warrants
Number of shares underlying warrants	7,400,934	22,328			80,966	225,869
Exercise price per share (in dollars per share)						$ 28.00	$ 28.00
Common stock warrants
Warrants
Number of shares underlying warrants	40,000
Common stock warrants, expiration date of February 2017 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	109,976
Exercise price per share (in dollars per share)	$ 28.00
Common stock warrants, expiration date of February 2017 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	29,260
Exercise price per share (in dollars per share)	$ 14.00
Common stock warrants, expiration date of March 2017 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	90,529
Exercise price per share (in dollars per share)	$ 28.00
Common stock warrants, expiration date of March 2017 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	29,557
Exercise price per share (in dollars per share)	$ 14.00
Common stock warrants, expiration date of April 2017 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	130,233
Exercise price per share (in dollars per share)	$ 28.00
Common stock warrants, expiration date of April 2017 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	2,275,950
Exercise price per share (in dollars per share)	$ 3.90
Common stock warrants, expiration date of April 2017 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	20,000
Exercise price per share (in dollars per share)	$ 4.49
Common stock warrants, expiration date of July 2017 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	14,284
Exercise price per share (in dollars per share)	$ 28.00
Common stock warrants, expiration date of August 2018 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	80,966
Exercise price per share (in dollars per share)	$ 28.00
Common stock warrants, expiration date of October 2018 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	4,551,900
Exercise price per share (in dollars per share)	$ 4.55
Common stock warrants, expiration date of October 2018 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	40,000
Exercise price per share (in dollars per share)	$ 5.23
Common stock warrants, expiration date of December 2018 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	3,571
Exercise price per share (in dollars per share)	$ 28.00
Common stock warrants, expiration date of October 2020 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	22,328
Exercise price per share (in dollars per share)	$ 8.40
Common stock warrants, expiration date of May 2022 \| Common Stock [Member]
Warrants
Number of shares underlying warrants	2,380
Exercise price per share (in dollars per share)	$ 8.68
Series B convertible preferred stock warrants \| Series B convertible preferred stock
Warrants
Number of shares underlying warrants			625,208
Exercise price per share (in dollars per share)			$ 0.2999
Series B convertible preferred stock warrants \| Term loan
Warrants
Face amount			$ 7.5