Earnings Per Common Share (Calculations) (Details) - $ / shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share, Diluted [Abstract]
Weighted average common shares outstanding	233.3	236.2	234.5	236.0
Effect of dilutive securities:
Stock options	0.3	0.6	0.4	0.5
Other stock compensation plans	0.7	0.7	0.7	0.7
Potentially dilutive common shares	1.0	1.3	1.1	1.2
Adjusted weighted average common shares outstanding	234.3	237.5	235.6	237.2
Dividends per common share (in dollars per share)	$ 0.68	$ 0.65	$ 1.98	$ 1.89
Outstanding stock options excluded from the computation of diluted earnings per share due to their antidilutive effect	1.6	0.4	1.3	0.9