Commitments and Contingencies - Additional Information for Operating Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 70.7	$ 73.0	$ 74.7
Sublease income	2.9	3.3	3.4
Accelerated rent	$ 1.0	$ (5.4)	$ 24.0