Warrants (Narrative) (Details) (USD $)
In Thousands, except Share data, unless otherwise specified

1 Months Ended

12 Months Ended

Mar. 31, 2014

Feb. 28, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Warrants Narrative Details

Common shares underlying warrants

2,100,000

6,526,000

8,091,000

5,131,000

Warrant exercise price, per share

$ 2.47

$ 3.08

$ 3.07

$ 7.28

Warrant term, in years

5 years

Loss on warrant exchange

$ 5,000

$ (4,967)

$ 1,900

Warrant Transactions Connected with Contingently Convertible Securities

In March 2014, we raised $13.9 million before issuance costs of approximately $1.0 million through an underwritten offering of 7.2 million shares of our common stock and warrants to purchase 2.1 million shares of our common stock. Each unit was sold to investors for $1.94 and consisted of one share of common stock and one warrant to purchase 0.3 shares of common stock. The warrants have an exercise price of $2.47 per share and expire on the fifth anniversary of the date of issuance.

In February 2014, we issued 3,713,309 shares of our common stock under the conditional exchange provision of the warrants. We did not receive additional cash consideration in the exchange transaction. We recorded a loss of $5.0 million during the year ended December 31, 2014 on the exchange, as the fair market value of the common stock issued was greater than the obligation recorded due to the increase in stock price from December 31, 2013 to the date the warrants were exchanged.