Cash and Cash Equivalents	6 Months Ended
Cash and Cash Equivalents	Jun. 30, 2016
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	Cash and Cash Equivalents 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, 2016 and December 31, 2015, the Company had cash and cash equivalents of $644.2 million and $373.2 million, respectively, which consisted of cash of $588.1 million and $367.2 million and investments of $56.1 million and $6.0 million at June 30, 2016 and December 31, 2015, respectively, in money market funds with original maturities of less than three months. Restricted Cash The Company had restricted cash of $1.4 million at both June 30, 2016 and December 31, 2015, which included $1.0 million at both June 30, 2016 and December 31, 2015 for an outstanding letter of credit associated with the Company’s lease for the office space in Parsippany, New Jersey. The funds are invested in certificates of deposit. The letter of credit 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 $0.1 million at both June 30, 2016 and December 31, 2015, in the form of a guaranteed investment certificate collateralizing an available credit facility. The Company also had restricted cash of $0.3 million at both June 30, 2016 and December 31, 2015, related to certain foreign tender requirements.

The entire disclosure for cash and cash equivalent footnotes, which may include the types of deposits and money market instruments, applicable carrying amounts, restricted amounts and compensating balance arrangements. Cash and equivalents include: (1) currency on hand (2) demand deposits with banks or financial institutions (3) other kinds of accounts that have the general characteristics of demand deposits (4) short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments maturing within three months from the date of acquisition qualify.