Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	PREFERRED STOCK	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	TREASURY STOCK
Beginning balance at Dec. 31, 2021	$ 12,016.8	$ 884.9	$ 408.6	$ 939.3	$ 13,117.3	$ (35.6)	$ (3,297.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	389.3				389.3
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	(871.4)					(871.4)
Dividends Declared:
Common Stock	(147.8)				(147.8)
Preferred Stock	(16.2)				(16.2)
Stock Awards and Options Exercised	72.9			(7.6)			80.5
Stock Purchased	(33.8)						(33.8)
Ending balance at Mar. 31, 2022	11,409.8	884.9	408.6	931.7	13,342.6	(907.0)	(3,251.0)
Beginning balance at Dec. 31, 2021	12,016.8	884.9	408.6	939.3	13,117.3	(35.6)	(3,297.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,180.3
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	(1,749.4)
Dividends Declared:
Stock Purchased	(35.2)
Ending balance at Sep. 30, 2022	11,030.4	884.9	408.6	963.6	13,806.3	(1,785.0)	(3,248.0)
Beginning balance at Mar. 31, 2022	11,409.8	884.9	408.6	931.7	13,342.6	(907.0)	(3,251.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	396.2				396.2
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	(603.6)					(603.6)
Dividends Declared:
Common Stock	(148.0)				(148.0)
Preferred Stock	(4.7)				(4.7)
Stock Awards and Options Exercised	20.3			19.4			0.9
Stock Purchased	(0.3)						(0.3)
Ending balance at Jun. 30, 2022	11,069.7	884.9	408.6	951.1	13,586.1	(1,510.6)	(3,250.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	394.8				394.8
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	(274.4)					(274.4)
Dividends Declared:
Common Stock	(158.4)				(158.4)
Preferred Stock	(16.2)				(16.2)
Stock Awards and Options Exercised	16.1			12.5			3.6
Stock Purchased	(1.2)						(1.2)
Ending balance at Sep. 30, 2022	11,030.4	884.9	408.6	963.6	13,806.3	(1,785.0)	(3,248.0)
Beginning balance at Dec. 31, 2022	11,259.5	884.9	408.6	983.5	13,798.5	(1,569.2)	(3,246.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	334.6				334.6
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	203.0					203.0
Dividends Declared:
Common Stock	(158.6)				(158.6)
Preferred Stock	(16.2)				(16.2)
Stock Awards and Options Exercised	66.4			(19.0)			85.4
Stock Purchased	(100.9)						(100.9)
Ending balance at Mar. 31, 2023	11,587.8	884.9	408.6	964.5	13,958.3	(1,366.2)	(3,262.3)
Beginning balance at Dec. 31, 2022	11,259.5	884.9	408.6	983.5	13,798.5	(1,569.2)	(3,246.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	994.2
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	205.8
Dividends Declared:
Stock Purchased	(201.3)
Ending balance at Sep. 30, 2023	11,847.2	884.9	408.6	993.1	14,281.6	(1,363.4)	(3,357.6)
Beginning balance at Mar. 31, 2023	11,587.8	884.9	408.6	964.5	13,958.3	(1,366.2)	(3,262.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	331.8				331.8
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	(39.7)					(39.7)
Dividends Declared:
Common Stock	(157.8)				(157.8)
Preferred Stock	(4.7)				(4.7)
Stock Awards and Options Exercised	17.6			15.5			2.1
Stock Purchased	(99.3)						(99.3)
Ending balance at Jun. 30, 2023	11,635.7	884.9	408.6	980.0	14,127.6	(1,405.9)	(3,359.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	327.8				327.8
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	42.5					42.5
Dividends Declared:
Common Stock	(157.6)				(157.6)
Preferred Stock	(16.2)				(16.2)
Stock Awards and Options Exercised	17.2			13.1			4.1
Stock Purchased	(1.1)						(1.1)
Excise Tax on Share Repurchases	(1.1)						(1.1)
Ending balance at Sep. 30, 2023	$ 11,847.2	$ 884.9	$ 408.6	$ 993.1	$ 14,281.6	$ (1,363.4)	$ (3,357.6)