Earnings Per Common Share (Calculations) (Details) - $ / shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share, Diluted [Abstract]
Weighted average common shares outstanding (in shares)	236.2	235.5	236.0	236.2
Effect of dilutive securities:
Stock options (in shares)	0.6	0.4	0.5	0.6
Other stock compensation plans (in shares)	0.7	0.7	0.7	0.7
Potentially dilutive common shares (in shares)	1.3	1.1	1.2	1.3
Adjusted weighted average common shares outstanding (in shares)	237.5	236.6	237.2	237.5
Dividends per common share (in dollars per share)	$ 0.65	$ 0.62	$ 1.89	$ 1.80
Antidilutive securities, stock options (in shares)	0.4	0.9	0.9	0.9