Earnings per Share (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Weighted Average Shares - Basic	169.6	170.9	170.9	170.2
Effect of dilutive securities	1.4	2.1	1.4	2.5
Weighted Average Shares - Diluted	171.0	173.0	172.3	172.7
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.1	0.0	0.5	0.0