Stock Based Incentive Compensation Plans (Summary of activity for stock options with performance conditions) (Details) - Stock options with performance conditions [Member] $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) $ / shares shares
Shares
Outstanding as of beginning of year (in shares) | shares	208,650
Granted - original (in shares) | shares	33,125
Exercised (includes shares tendered) (in shares) | shares	(52,518)
Forfeited or expired (in shares) | shares	(22,979)
Outstanding as of end of year (in shares) | shares	166,278
Vested or expected to vest as of end of year (in shares) | shares	157,122
Exercisable as of end of year (in shares) | shares	135,759
Summary of activity for stock options, additional disclosures [Abstract]
Weighted average exercise price as of beginning of year (in dollars per share) | $ / shares	$ 52.70
Weighted average exercise price granted - original (in dollars per share) | $ / shares	61.71
Weighted average exercise price exercised (includes shares tendered) (in dollars per share) | $ / shares	43.94
Weighted average exercise price forfeited or expired (in dollars per share) | $ / shares	41.00
Weighted average exercise price outstanding as of end of year (in dollars per share) | $ / shares	58.88
Weighted average exercise price vested or expected to vest as of end of year (in dollars per share) | $ / shares	59.75
Weighted average exercise price exercisable as of end of year (in dollars per share) | $ / shares	$ 62.23
Weighted average remaining contractual term outstanding as of end of year (in years)	1 year 11 months 1 day
Weighted average remaining contractual term vested or expected to vest as of end of year (in years)	1 year 9 months 21 days
Weighted average remaining contractual term exercisable as of end of year (in years)	1 year 6 months 3 days
Aggregate intrinsic value outstanding as of end of year | $	$ 2
Aggregate intrinsic value vested or expected to vest as of end of year | $	2
Aggregate intrinsic value exercisable as of end of year | $	$ 1