Schedule of Changes in Unrecognized Income Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2012
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Increases in prior period tax positions	$ 4.2	$ 2.0	$ 0.1
Decreases in prior period tax positions	(0.6)	(0.6)	(5.8)
Increases in current period tax positions	1.3	0.7	60.4
Unrecognized tax benefits	15.0	73.4	72.8	$ 15.0	$ 29.2
Expiration of the statute of limitations	(0.7)	(0.5)	(0.7)
Settlements	(62.1)	(0.7)	(8.6)
Interest and penalties, net	(0.5)	(0.3)	(1.8)
Ending balance	$ 15.0	73.4	$ 72.8
Income tax penalties and interest accrued				3.9
Unrecognized tax benefits that would impact effective tax rate				12.0
Unrecognized tax benefits that will be recognized within 12 months of year end				$ 4.0
Temporary difference [Member]
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Unrecognized tax benefits		60.9
Ending balance		$ 60.9