Earnings Per Share (EPS) (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Weighted-average number of basic shares	95.1	95.0	95.1	95.2
Shares issuable under incentive stock plans	0.7	0.8	0.7	0.8
Weighted average number of diluted shares	95.8	95.8	95.8	96.0