Common Stock and Warrants (Narrative) (Details) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

Mar. 31, 2014

Feb. 28, 2014

Sep. 30, 2013

May 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Common Stock And Warrants Narrative Details

Number of shares of common stock issued

7,200,000

3,713,309

3,500,000

2,600,000

Cash received from stock sale, before issuance costs

$ 13,900,000

$ 0

$ 6,600,000

$ 5,850,000

$ 12,848,000

$ 4,262,000

Stock issuance costs

$ 1,000,000

$ 452,000

$ 362,000

Common shares underlying warrants

2,100,000

2,100,000

Warrant exercise price, per share

$ 2.47

$ 2.47

Date from which warrants are exercisable

Sep. 30, 2014

Warrant term, in years

5 years

Warrant terms and provisions

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, are exercisable beginning six months from the date of issuance, 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 warrant exchange provisions of our May and September 2013 registered direct offerings. Under the warrant exchange provisions, the holders could elect to exchange the warrants for a variable number of shares of common stock as determined by a formula included in the warrants. We did not receive additional cash consideration in the exchange transaction. During the three months ended March 31, 2014, we recognized a loss of $5.0 million on the exchange as the fair market value of the common stock issued was greater than the obligation recorded due to an increase in our stock price since December 31, 2013.

In September 2013, we raised $6.6 million before issuance costs of approximately $452,000 from the sale of 3.5 million shares of common stock and warrants to purchase up to an aggregate of 2.1 million shares of our common stock in a registered direct offering.

In May 2013, we raised $5.85 million before issuance costs of approximately $362,000 from the sale of 2.6 million shares of common stock and warrants to purchase up to an aggregate of 2.0 million shares of our common stock in a registered direct offering.