Common and Preferred Stock	12 Months Ended
Dec. 31, 2017
Equity [Abstract]
Common and Preferred Stock	11. Common and Preferred Stock On December 13, 2017, the Company approved a proposal to amend the Company’s Amended and Restated Certificate of Incorporation to increase the authorized number of shares of the Company’s common stock from 140,000,000 to 280,000,000 shares. The Company is authorized to issue 280,000,000 shares of common stock, par value $0.01 per share, and 10,000,000 shares of undesignated preferred stock, par value $0.01 per share, issuable in one or more series as designated by the Company’s board of directors. No other class of capital stock is authorized. As of December 31, 2017 and 2016, 119,053,414 and 95,680,831 shares of common stock, respectively, were issued and outstanding and no shares of preferred stock were outstanding. In November 2017, the Company sold an aggregate of 173,327 shares of the Company’s common stock at a purchase price of $3.15 per share pursuant to the Company’s At Market Issuance Sales Agreement with FBR Capital Markets & Co. The aggregate gross proceeds from the sales were approximately $0.5 million. On October 10, 2017, the Company entered into securities purchase agreements (the “Purchase Agreements”) with certain institutional investors and a charitable foundation (collectively, the “Purchasers”). Pursuant to the terms of the Purchase Agreements, the Company sold to the Purchasers in a registered offering an aggregate of 10,166,600 shares of the Company’s common stock at a purchase price of $6.00 per share. Included in this offering was 166,600 shares issued to a charitable foundation associated with the Chairman of the Company’s board of directors. The net proceeds to the Company from the offering were approximately $57.7 million, after deducting placement agent fees equal to 5.0% of the aggregate gross proceeds from the offering (except for the proceeds received from the sale of 166,600 shares issued to the charitable foundation) and offering expenses payable by the Company . The offering closed on October 13, 2017. On March 1, 2017, the Company effected a 1-for-5 reverse stock split of the Company’s outstanding common stock. As a result, prior to March 1, 2017, all common stock share amounts included in these consolidated financial statements have been retroactively reduced by a factor of five, and all common stock per share amounts have been increased by a factor of five, with the exception of the Company’s common stock par value. See Note 1 — Description of Business. On November 9, 2015, the Company entered into a series of stock purchase agreements to sell up to an aggregate of 10,000,000 shares of its common stock in a registered direct offering to selected investment funds in Israel that hold securities included within certain stock indexes of the Tel Aviv Stock Exchange (the “TASE”). Pursuant to the agreements, the shares of common stock were sold at a price per share equal to 97% of the closing price of the Company’s common stock on the TASE on November 12, 2015. During November 2015, the Company sold 2,770,487 shares of common stock for an aggregate price of approximately $34,710,000, or $13.05 per share, which is net of $1,432,000 of issuance costs. The Company engaged Sunrise Securities Corporation as its exclusive placement agent in connection with the offering of the 10,000,000 shares. In connection with the services provided, the Company issued to Sunrise Securities Corporation, or its designee, restricted warrants to purchase a number of shares of the Company’s common stock in an aggregate equal to 1.15% of the aggregate shares sold in the offering, which totaled approximately 32,000 shares on November 16, 2015. The warrants are exercisable for a five year period at an exercise price of $13.05, the price paid per share in connection with the offering. The Company had an obligation to register the common stock that may be issued pursuant to the exercise of the warrants, which resulted in their initial classification as liability and were deemed immaterial. On December 15, 2015 the warrants were reclassified to equity as the Company registered the common stock pursuant to a registration statement and continue to be classified in equity as of December 31, 2017. The Company’s stock was delisted from the TASE in November of 2017. During 2014, the Company loaned to Bank of America 1,800,000 shares of common stock under a share lending agreement in connection with the offering of the $100.0 million aggregate principal amount of the 2015 notes. Bank of America was obligated to return the borrowed shares (or, in certain circumstances, the cash value thereof) to the Company on or about the 45th business day following the date as of which the entire principal amount of the 2015 notes ceases to be outstanding, subject to extension or acceleration in certain circumstances or early termination at Bank of America’s option. On October 23, 2015, the 1,800,000 shares of common stock loaned to Bank of America were returned, as the Company settled all payments and deliveries in respect of such convertible notes on August 17, 2015. The Company did not receive any proceeds from the sale of the borrowed shares by Bank of America, but the Company did receive a nominal lending fee of $0.05 per share from Bank of America for the use of borrowed shares. For the year ended December 31, 2015, the Company received $10.1 million in proceeds from the exercise of the February 2012 public offering warrants. There were no warrant exercises during the year ended December 31, 2016 and any unexercised February 2012 public offering warrants expired on February 8, 2016.

11. Common and Preferred Stock

On December 13, 2017, the Company approved a proposal to amend the Company’s Amended and Restated Certificate of Incorporation to increase the authorized number of shares of the Company’s common stock from 140,000,000 to 280,000,000 shares. The Company is authorized to issue 280,000,000 shares of common stock, par value $0.01 per share, and 10,000,000 shares of undesignated preferred stock, par value $0.01 per share, issuable in one or more series as designated by the Company’s board of directors. No other class of capital stock is authorized. As of December 31, 2017 and 2016, 119,053,414 and 95,680,831 shares of common stock, respectively, were issued and outstanding and no shares of preferred stock were outstanding.

In November 2017, the Company sold an aggregate of 173,327 shares of the Company’s common stock at a purchase price of $3.15 per share pursuant to the Company’s At Market Issuance Sales Agreement with FBR Capital Markets & Co. The aggregate gross proceeds from the sales were approximately $0.5 million.

On October 10, 2017, the Company entered into securities purchase agreements (the “Purchase Agreements”) with certain institutional investors and a charitable foundation (collectively, the “Purchasers”). Pursuant to the terms of the Purchase Agreements, the Company sold to the Purchasers in a registered offering an aggregate of 10,166,600 shares of the Company’s common stock at a purchase price of $6.00 per share. Included in this offering was 166,600 shares issued to a charitable foundation associated with the Chairman of the Company’s board of directors. The net proceeds to the Company from the offering were approximately $57.7 million, after deducting placement agent fees equal to 5.0% of the aggregate gross proceeds from the offering (except for the proceeds received from the sale of 166,600 shares issued to the charitable foundation) and offering expenses payable by the Company . The offering closed on October 13, 2017.

On March 1, 2017, the Company effected a 1-for-5 reverse stock split of the Company’s outstanding common stock. As a result, prior to March 1, 2017, all common stock share amounts included in these consolidated financial statements have been retroactively reduced by a factor of five, and all common stock per share amounts have been increased by a factor of five, with the exception of the Company’s common stock par value. See Note 1 — Description of Business.

On November 9, 2015, the Company entered into a series of stock purchase agreements to sell up to an aggregate of 10,000,000 shares of its common stock in a registered direct offering to selected investment funds in Israel that hold securities included within certain stock indexes of the Tel Aviv Stock Exchange (the “TASE”). Pursuant to the agreements, the shares of common stock were sold at a price per share equal to 97% of the closing price of the Company’s common stock on the TASE on November 12, 2015. During November 2015, the Company sold 2,770,487 shares of common stock for an aggregate price of approximately $34,710,000, or $13.05 per share, which is net of $1,432,000 of issuance costs.

The Company engaged Sunrise Securities Corporation as its exclusive placement agent in connection with the offering of the 10,000,000 shares. In connection with the services provided, the Company issued to Sunrise Securities Corporation, or its designee, restricted warrants to purchase a number of shares of the Company’s common stock in an aggregate equal to 1.15% of the aggregate shares sold in the offering, which totaled approximately 32,000 shares on November 16, 2015. The warrants are exercisable for a five year period at an exercise price of $13.05, the price paid per share in connection with the offering. The Company had an obligation to register the common stock that may be issued pursuant to the exercise of the warrants, which resulted in their initial classification as liability and were deemed immaterial. On December 15, 2015 the warrants were reclassified to equity as the Company registered the common stock pursuant to a registration statement and continue to be classified in equity as of December 31, 2017.

The Company’s stock was delisted from the TASE in November of 2017.

During 2014, the Company loaned to Bank of America 1,800,000 shares of common stock under a share lending agreement in connection with the offering of the $100.0 million aggregate principal amount of the 2015 notes. Bank of America was obligated to return the borrowed shares (or, in certain circumstances, the cash value thereof) to the Company on or about the 45th business day following the date as of which the entire principal amount of the 2015 notes ceases to be outstanding, subject to extension or acceleration in certain circumstances or early termination at Bank of America’s option. On October 23, 2015, the 1,800,000 shares of common stock loaned to Bank of America were returned, as the Company settled all payments and deliveries in respect of such convertible notes on August 17, 2015. The Company did not receive any proceeds from the sale of the borrowed shares by Bank of America, but the Company did receive a nominal lending fee of $0.05 per share from Bank of America for the use of borrowed shares.

For the year ended December 31, 2015, the Company received $10.1 million in proceeds from the exercise of the February 2012 public offering warrants. There were no warrant exercises during the year ended December 31, 2016 and any unexercised February 2012 public offering warrants expired on February 8, 2016.