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

1 Months Ended

3 Months Ended

6 Months Ended

Mar. 31, 2014

Feb. 28, 2014

Jun. 30, 2015

Mar. 31, 2015

Jun. 30, 2014

Jun. 30, 2015

Jun. 30, 2014

Common Stock And Warrants Narrative Details

Exchange of warrants

$ 0

$ 9,869,000

Exchange of warrants, shares

3,700,000

1,500,000

Cash on exercise of warrants

$ 3,300,000

Number of shares of common stock issued

7,200,000

555,000

Loss on warrant exchange

$ (5,000,000)

$ 0

$ 0

$ (4,967,000)

Cash received from stock sale, before issuance costs

$ 13,900,000

1,800,000

$ 1,000,000

Stock issuance costs

$ 1,000,000

$ 71,000

Common shares underlying warrants

2,100,000

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.

In February 2014, we issued 3.7 million shares of our common stock under the warrant exchange provisions of our May and September 2013 registered direct offerings. 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 to the date the warrants were exchanged.

In May 2015, we entered into an At-the-Market (ATM) agreement with Meyers Associates, L.P. Under the terms of the agreement, we may, from time to time, at our discretion, offer and sell shares of our common stock having an aggregate value of up to $6.0 million. During the three months ended June 30, 2015, we received gross proceeds of $1.8 million before issuance costs of approximately $71,000 from the sale of 555,000 shares of our common stock.

During the three months ended March 31, 2015, we received gross proceeds of $1.0 million as part of an At-the-Market (ATM) agreement we entered into with Meyers Associates, L.P. in June 2014. We have completed sales under this agreement, having received total proceeds of $4.5 million before issuance costs of approximately $206,000 from the sale of 2.0 million shares of our common stock.

During the six months ended June 30, 2015, we received $3.3 million from the exercise of warrants we issued in connection with earlier financing transactions to purchase 1.5 million shares of our common stock.