Fan Pier Leases	12 Months Ended
Dec. 31, 2013
Fan Pier Leases [Abstract]
Fan Pier Leases	Fan Pier Leases In 2011, the Company entered into two lease agreements, pursuant to which the Company leases approximately 1.1 million square feet of office and laboratory space in two buildings (the "Buildings") at Fan Pier in Boston, Massachusetts (the “Fan Pier Leases”). The Company commenced lease payments in December 2013, and will make lease payments pursuant to the Fan Pier Leases through December 2028. The Company has an option to extend the term of the Fan Pier Leases for an additional 10 years. Because the Company was involved in the construction project, including having responsibility to pay for a portion of the costs of finish work and structural elements of the Buildings, the Company was deemed for accounting purposes to be the owner of the Buildings during the construction period. Therefore, the Company recorded project construction costs incurred by the landlord as an asset and a related financing obligation during the construction period. The Company evaluated the Fan Pier Leases in the fourth quarter of 2013 and determined that the Fan Pier Leases did not meet the criteria for “sale-leaseback” treatment. This determination was based on, among other things, the Company's continuing involvement with the property in the form of non-recourse financing to the lessor. Accordingly, the Company began depreciating the asset and incurring interest expense related to the financing obligation during the fourth quarter of 2013. The Company bifurcates its lease payments pursuant to the Fan Pier Leases into (i) a portion that is allocated to the Buildings and (ii) a portion that is allocated to the land on which the Buildings were constructed. The portion of the lease obligations allocated to the land is treated as an operating lease that commenced in 2011. Property and equipment, net, included $506.1 million and $290.7 million as of December 31, 2013 and 2012, respectively, related to construction costs for the Buildings. The construction financing lease obligations related to the Buildings on the Company's consolidated balance sheets were $440.9 million and $268.0 million, respectively, as of December 31, 2013 and 2012.

Fan Pier Leases

In 2011, the Company entered into two lease agreements, pursuant to which the Company leases approximately 1.1 million square feet of office and laboratory space in two buildings (the "Buildings") at Fan Pier in Boston, Massachusetts (the “Fan Pier Leases”). The Company commenced lease payments in December 2013, and will make lease payments pursuant to the Fan Pier Leases through December 2028. The Company has an option to extend the term of the Fan Pier Leases for an additional 10 years.

Because the Company was involved in the construction project, including having responsibility to pay for a portion of the costs of finish work and structural elements of the Buildings, the Company was deemed for accounting purposes to be the owner of the Buildings during the construction period. Therefore, the Company recorded project construction costs incurred by the landlord as an asset and a related financing obligation during the construction period. The Company evaluated the Fan Pier Leases in the fourth quarter of 2013 and determined that the Fan Pier Leases did not meet the criteria for “sale-leaseback” treatment. This determination was based on, among other things, the Company's continuing involvement with the property in the form of non-recourse financing to the lessor. Accordingly, the Company began depreciating the asset and incurring interest expense related to the financing obligation during the fourth quarter of 2013. The Company bifurcates its lease payments pursuant to the Fan Pier Leases into (i) a portion that is allocated to the Buildings and (ii) a portion that is allocated to the land on which the Buildings were constructed. The portion of the lease obligations allocated to the land is treated as an operating lease that commenced in 2011.

Property and equipment, net, included $506.1 million and $290.7 million as of December 31, 2013 and 2012, respectively, related to construction costs for the Buildings. The construction financing lease obligations related to the Buildings on the Company's consolidated balance sheets were $440.9 million and $268.0 million, respectively, as of December 31, 2013 and 2012.