Subsequent Events	9 Months Ended
Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	On November 14, 2018, the Company entered into a Securities Purchase Agreement (the “Purchase Agreement”) with an existing investor, pursuant to which the Company agreed to issue and sell, in a registered direct offering (the “Offering”), Pre-Funded Series K Warrants (the “Pre-Funded Series K Warrants”) to purchase 1,666,666 shares of common stock (and the shares of Common Stock issuable upon exercise of the Pre-Funded Series K Warrants (the “Warrant Shares”)), in lieu of shares of common stock because the purchase of common stock would have caused the beneficial ownership of the Purchaser, together with its affiliates and certain related parties, to exceed 9.99% of the Company’s outstanding common stock. The price to the Purchaser for each Pre-Funded Series K Warrant was $0.59 and the Pre-Funded Series K Warrants are immediately exercisable at a price of $0.01 per share of common stock. The Company received approximately $983 million in gross proceeds from the Offering before the deduction of fees and offering expenses. The Pre-Funded Series K Warrants and the Warrant Shares are being offered by the Company pursuant to a registration statement on Form S-3 (File No. 333-227858), which was initially filed with the Securities and Exchange Commission (the “Commission”) on October 16, 2018 and was declared effective by the Commission on November 9, 2018 (the “Registration Statement”).

Subsequent Events

9 Months Ended

Sep. 30, 2018

On November 14, 2018, the Company entered into a Securities Purchase Agreement (the “Purchase Agreement”) with an existing investor, pursuant to which the Company agreed to issue and sell, in a registered direct offering (the “Offering”), Pre-Funded Series K Warrants (the “Pre-Funded Series K Warrants”) to purchase 1,666,666 shares of common stock (and the shares of Common Stock issuable upon exercise of the Pre-Funded Series K Warrants (the “Warrant Shares”)), in lieu of shares of common stock because the purchase of common stock would have caused the beneficial ownership of the Purchaser, together with its affiliates and certain related parties, to exceed 9.99% of the Company’s outstanding common stock. The price to the Purchaser for each Pre-Funded Series K Warrant was $0.59 and the Pre-Funded Series K Warrants are immediately exercisable at a price of $0.01 per share of common stock. The Company received approximately $983 million in gross proceeds from the Offering before the deduction of fees and offering expenses. The Pre-Funded Series K Warrants and the Warrant Shares are being offered by the Company pursuant to a registration statement on Form S-3 (File No. 333-227858), which was initially filed with the Securities and Exchange Commission (the “Commission”) on October 16, 2018 and was declared effective by the Commission on November 9, 2018 (the “Registration Statement”).