Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Income	$ 57.8	$ 60.2	$ 193.1	$ 172.9
Weighted Average Shares:
Basic (shares)	319.7	329.7	322.1	329.9
Dilutive effect of RSUs (shares)	0.7	0.7	0.8	0.8
Diluted (shares)	320.4	330.4	322.9	330.7
Income Per Share - Basic (in dollars per share)	$ 0.18	$ 0.18	$ 0.60	$ 0.52
Income Per Share - Diluted (in dollars per share)	$ 0.18	$ 0.18	$ 0.60	$ 0.52