Commitments and Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Rental expense	$ 13.3	$ 7.6	$ 4.7
Operating Leases Entered Since Prior Year End Future Minimum Payments Due	11.2
Other Commitments [Line Items]
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, increase	$ 9.4
Acquisition Fee, Percentage of Consideration Due	2.50%
London Lease [Member] | Financial Standby Letter of Credit [Member]
Other Commitments [Line Items]
Letters of Credit Outstanding, Amount	$ 0.5