Stock-Based Incentive Compensation Plans (Option price assumptions used for stock option incentive plans) (Details) - Stock Options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assumptions:
Weighted-average fair value per option granted (in dollars per share)	$ 12.25	$ 13.23	$ 18.74
Dividend yield	3.00%	2.80%	2.10%
Expected volatility	30.10%	26.90%	27.20%
Risk-free interest rate, minimum	0.30%	2.10%	2.50%
Risk-free interest rate, maximum	1.40%	2.50%	2.90%
Expected life (in years)	5 years 9 months 18 days	5 years 9 months 18 days	5 years 9 months 18 days