Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	PREFERRED STOCK	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	TREASURY STOCK
Balance, beginning of period at Dec. 31, 2019	$ 11,080.9	$ 1,273.4	$ 408.6	$ 1,013.1	$ 11,646.6	$ (194.7)	$ (3,066.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,209.3				1,209.3
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	622.7					622.7
Dividends Declared:
Common Stock	(592.0)				(592.0)
Preferred Stock	(44.7)				(44.7)
Stock Purchased	(400.0)	(388.5)			(11.5)
Redemption of Preferred Stock, Series C	(299.8)						(299.8)
Stock Awards and Options Exercised	111.9			(49.5)			161.4
Balance, end of period at Dec. 31, 2020	11,688.3	884.9	408.6	963.6	12,207.7	428.0	(3,204.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,545.3				1,545.3
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	(463.6)					(463.6)
Dividends Declared:
Common Stock	(593.9)				(593.9)
Preferred Stock	(41.8)				(41.8)		0.0
Redemption of Preferred Stock, Series C	(267.6)						(267.6)
Stock Awards and Options Exercised	150.1			(24.3)			174.4
Balance, end of period 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	1,336.0				1,336.0
Other Comprehensive Income (Loss) (Net of Tax and Reclassifications)	(1,533.6)					(1,533.6)
Dividends Declared:
Common Stock	(613.0)				(613.0)
Preferred Stock	(41.8)				(41.8)
Redemption of Preferred Stock, Series C	(35.4)						(35.4)
Stock Awards and Options Exercised	130.5			44.2			86.3
Balance, end of period at Dec. 31, 2022	$ 11,259.5	$ 884.9	$ 408.6	$ 983.5	$ 13,798.5	$ (1,569.2)	$ (3,246.8)