Change in Financial Statement due to adoption of Policy (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Item Effected [Line Items]
Net cash provided by operating activities	$ 747.5	$ 1,259.2	$ 1,198.1
Net cash used in financing activities	$ 1,607.2	(1,042.9)	(505.5)
As Previously Reported [Member]
Item Effected [Line Items]
Net cash provided by operating activities		1,226.1	1,153.6
Net cash used in financing activities		(1,009.8)	(461.0)
Reclassification [Member]
Item Effected [Line Items]
Net cash provided by operating activities		33.1	44.5
Net cash used in financing activities		$ (33.1)	$ (44.5)