Commitments and Contingencies (Details) $ in Millions	Dec. 31, 2015 USD ($)
Minimum rental commitments under non-cancelable leases
Minimum lease payments, 2016	$ 75.9	[1]
Minimum lease payments, 2017	75.7	[1]
Minimum lease payments, 2018	67.9	[1]
Minimum lease payments, 2019	66.7	[1]
Minimum lease payments, 2020	63.2	[1]
Minimum lease payments, Thereafter	382.7	[1]
Minimum lease payments, Total	732.1	[1]
Less: income from subleases, 2016	(6.0)
Less: income from subleases, 2017	(6.0)
Less: income from subleases, 2018	(6.3)
Less: income from subleases, 2019	(6.3)
Less: income from subleases, 2020	(6.3)
Less: income from subleases, Thereafter	(28.9)
Less: income from subleases, Total	(59.8)
Net minimum lease payments, 2016	69.9
Net minimum lease payments, 2017	69.7
Net minimum lease payments, 2018	61.6
Net minimum lease payments, 2019	60.4
Net minimum lease payments, 2020	56.9
Net minimum lease payments, Thereafter	353.8
Net minimum lease payments, Total	$ 672.3

[1] As a result of our decision to relocate our corporate headquarters to Cambridge, Massachusetts, we vacated part of our Weston, Massachusetts facility in the fourth quarter of 2013. We incurred a charge of $27.2 million in connection with this move. This charge represented our remaining lease obligation for the vacated portion of our Weston, Massachusetts facility, net of sublease income expected to be received. The term of our sublease to the vacated portion of our Weston, Massachusetts facility started in January 2014 and will continue through the remaining term of our lease agreement.