CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total		Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock, Common
Balance at Beginning of Year at Dec. 31, 2020			$ 30.7	$ 2,376.2	$ (6,310.2)	$ 11,249.0	$ (3,179.7)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.0	31.9
Other Comprehensive Income	$ 1,145.6				1,145.6
Net Income	981.0					981.0
Dividends to Stockholders (per common share: $1.39; $1.26; $1.17)						(240.6)
Purchases of Treasury Stock	(50.0)	[1]					(50.0)
Treasury Stock, Retired, Cost Method, Amount			0.0	0.0		0.0	0.0
Balance at End of Year at Dec. 31, 2021	6,033.9		30.7	2,408.1	(5,164.6)	11,989.4	(3,229.7)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.1	32.9
Other Comprehensive Income	1,716.3				1,716.3
Net Income	1,407.2					1,407.2
Dividends to Stockholders (per common share: $1.39; $1.26; $1.17)						(255.3)
Purchases of Treasury Stock	(200.1)	[1]					(200.1)
Treasury Stock, Retired, Cost Method, Amount			0.0	0.0		0.0	0.0
Balance at End of Year at Dec. 31, 2022	8,735.0		30.8	2,441.0	(3,448.3)	13,141.3	(3,429.8)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.1	21.3
Other Comprehensive Income	140.3				140.3
Net Income	1,283.8					1,283.8
Dividends to Stockholders (per common share: $1.39; $1.26; $1.17)						(277.1)
Purchases of Treasury Stock	(252.0)	[1]					(252.0)
Treasury Stock, Retired, Cost Method, Amount	(3,642.5)		(11.5)	(914.5)		(2,716.5)	(3,642.5)
Balance at End of Year at Dec. 31, 2023	$ 9,651.4		$ 19.4	$ 1,547.8	$ (3,308.0)	$ 11,431.5	$ (39.3)

[1] Includes $0.1 million of commissions for the years ended December 31, 2023 and 2022, respectively. There were no commissions for the year ended December 31, 2021. Also includes $1.9 million of excise tax for the year ended December 31, 2023. There were no excise taxes during the years ended December 31, 2022 and 2021.