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, 2023			$ 19.4	$ 1,547.8	$ (3,308.0)	$ 11,431.5	$ (39.3)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.1	11.0
Cost of Shares Repurchased	$ (302.8)	[1]		0.0			(302.8)
Other Comprehensive Income	461.8
Net Income	784.7					784.7
Dividends to Stockholders (per common share: $0.420; $0.365; $0.840; $0.730)						(141.6)
Balance at End of Year at Jun. 30, 2024	10,464.6		19.5	1,558.8	(2,846.2)	12,074.6	(342.1)
Balance at Beginning of Year at Mar. 31, 2024			19.5	1,548.2	(2,940.0)	11,754.1	(162.3)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.0	10.6
Cost of Shares Repurchased	(179.8)	[1]		0.0			(179.8)
Other Comprehensive Income	93.8				93.8
Net Income	389.5					389.5
Dividends to Stockholders (per common share: $0.420; $0.365; $0.840; $0.730)						(69.0)
Balance at End of Year at Jun. 30, 2024	10,464.6		19.5	1,558.8	(2,846.2)	12,074.6	(342.1)
Balance at Beginning of Year at Dec. 31, 2024	10,961.1		19.5	1,489.6	(2,523.7)	12,914.0	(938.3)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.1	8.5
Cost of Shares Repurchased	(505.9)	[1]		(80.3)			(586.2)
Other Comprehensive Income	483.0				483.0
Net Income	524.7					524.7
Dividends to Stockholders (per common share: $0.420; $0.365; $0.840; $0.730)						(151.5)
Balance at End of Year at Jun. 30, 2025	11,320.0		19.6	1,578.4	(2,040.7)	13,287.2	(1,524.5)
Balance at Beginning of Year at Mar. 31, 2025			19.5	1,568.7	(2,178.8)	13,025.8	(1,221.2)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.1	9.7
Cost of Shares Repurchased	(303.3)	[1]		0.0			(303.3)
Other Comprehensive Income	138.1				138.1
Net Income	335.6					335.6
Dividends to Stockholders (per common share: $0.420; $0.365; $0.840; $0.730)						(74.2)
Balance at End of Year at Jun. 30, 2025	$ 11,320.0		$ 19.6	$ 1,578.4	$ (2,040.7)	$ 13,287.2	$ (1,524.5)

[1] 2Includes $0.4 million and $0.9 million of commissions for the three and six months ended June 30, 2025, respectively, and a de minimis amount of commissions for the three and six months ended June 30, 2024. Also includes $2.9 million and $5.0 million of excise tax for the three and six months ended June 30, 2025, respectively, and $1.7 million and $2.8 million of excise tax for the three and six months ended June 30, 2024, respectively.