Consolidated Statement of Changes in Equity (Parenthetical) $ in Millions					12 Months Ended
	Feb. 07, 2023 $ / shares shares	Aug. 19, 2022 $ / shares shares	Apr. 26, 2022 $ / shares shares	Sep. 13, 2021 $ / shares shares	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares	Nov. 01, 2023 shares	Nov. 01, 2022 shares
Par value less than $.5 million at each date | $					$ 0.5	$ 0.5	$ 0.5
Common stock held in treasury at cost (shares)					145,087,054	142,298,689
Common stock
Common stock activity, shares					500,000	500,000	500,000
Depositary Shares
Common stock held in treasury at cost (shares)								1,000,000	60,000,000
Series T Preferred Stock
Common stock activity, shares				1,500,000
Depositary shares, conversion ratio				0.01
Preferred stock, dividend rate, percentage				3.40%
Preferred stock, par value (in dollars per share) | $ / shares				$ 1
Series U Preferred Stock
Common stock activity, shares			1,000,000
Depositary shares, conversion ratio			0.01
Preferred stock, dividend rate, percentage			6.00%
Preferred stock, par value (in dollars per share) | $ / shares			$ 1
Series V Preferred Stock
Common stock activity, shares		1,250,000
Depositary shares, conversion ratio		0.01
Preferred stock, dividend rate, percentage		6.20%
Preferred stock, par value (in dollars per share) | $ / shares		$ 1
Series P Preferred Stock
Treasury stock, preferred (shares)									15,000
Depositary shares, conversion ratio									0.01
Series W Preferred Stock
Common stock activity, shares	1,500,000
Depositary shares, conversion ratio	0.01
Preferred stock, dividend rate, percentage	6.25%
Preferred stock, par value (in dollars per share) | $ / shares	$ 1
Series O Preferred Stock
Treasury stock, preferred (shares)								10,000
Depositary shares, conversion ratio								0.01