Cash and Cash Equivalents and Investments	6 Months Ended
Jun. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Cash and Cash Equivalents and Investments	Cash and Cash Equivalents and Investments The Company considers all highly liquid investments purchased with original maturities at the date of purchase of three months or less to be cash equivalents. At June 30, 2018 and December 31, 2017, the Company had cash and cash equivalents of $162.5 million and $151.4 million, respectively, which consisted of cash of $150.3 million and $139.3 million, and money market funds with original maturities of less than three months of $12.2 million and $12.1 million at June 30, 2018 and December 31, 2017, respectively. As of June 30, 2018, the Company’s common stock investment in Melinta had a readily determinable fair value of $21.0 million. During the three and six months ended June 30, 2018, the Company recognized a loss of $3.5 million and $33.5 million, respectively, all of which was unrealized, in the accompanying condensed consolidated statements of operations, relating to the Company’s investment in Melinta. Restricted Cash The Company had restricted cash of $5.4 million and $5.5 million at June 30, 2018 and December 31, 2017, respectively, which included $4.2 million and $1.0 million reserved for an outstanding letter of credit associated with foreign taxes and the Company’s lease for the office space in Parsippany, New Jersey, respectively, at both June 30, 2018 and December 31, 2017, respectively. These funds are invested in certificates of deposit. The letter of credit for the Company’s lease for the office space in Parsippany, New Jersey permits draws by the landlord to cure defaults by the Company. In addition, as a result of the acquisition of Targanta Therapeutics Corporation (Targanta) in 2009, the Company had restricted cash of $0.2 million at December 31, 2017, in the form of a guaranteed investment certificate collateralizing an available credit facility, which was settled at June 30, 2018. The Company also had restricted cash of $0.2 million and $0.3 million at June 30, 2018 and December 31, 2017, respectively, related to certain foreign tender requirements.

Cash and Cash Equivalents and Investments

The Company considers all highly liquid investments purchased with original maturities at the date of purchase of three months or less to be cash equivalents. At June 30, 2018 and December 31, 2017, the Company had cash and cash equivalents of $162.5 million and $151.4 million, respectively, which consisted of cash of $150.3 million and $139.3 million, and money market funds with original maturities of less than three months of $12.2 million and $12.1 million at June 30, 2018 and December 31, 2017, respectively.

As of June 30, 2018, the Company’s common stock investment in Melinta had a readily determinable fair value of $21.0 million. During the three and six months ended June 30, 2018, the Company recognized a loss of $3.5 million and $33.5 million, respectively, all of which was unrealized, in the accompanying condensed consolidated statements of operations, relating to the Company’s investment in Melinta.

Restricted Cash

The Company had restricted cash of $5.4 million and $5.5 million at June 30, 2018 and December 31, 2017, respectively, which included $4.2 million and $1.0 million reserved for an outstanding letter of credit associated with foreign taxes and the Company’s lease for the office space in Parsippany, New Jersey, respectively, at both June 30, 2018 and December 31, 2017, respectively. These funds are invested in certificates of deposit. The letter of credit for the Company’s lease for the office space in Parsippany, New Jersey permits draws by the landlord to cure defaults by the Company. In addition, as a result of the acquisition of Targanta Therapeutics Corporation (Targanta) in 2009, the Company had restricted cash of $0.2 million at December 31, 2017, in the form of a guaranteed investment certificate collateralizing an available credit facility, which was settled at June 30, 2018. The Company also had restricted cash of $0.2 million and $0.3 million at June 30, 2018 and December 31, 2017, respectively, related to certain foreign tender requirements.