Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	COMMON STOCK, $1 PAR VALUE:	ADDITIONAL PAID-IN CAPITAL:	TREASURY STOCK, AT COST:	RETAINED EARNINGS:	ACCUMULATED OTHER COMPREHENSIVE LOSS:
Beginning balance at Dec. 31, 2020		$ 346.6	$ 88.5		$ 11,148.5	$ (1,050.3)
Net income	$ 1,865.5				1,865.5
Purchases, shares: 2023 - .05; 2022 - .04; 2021 - .02				$ (1.5)
Cash dividends declared on common stock, per share: 2023 - $4.24; 2022 - $2.80; 2021 - $1.89					(988.2)
Treasury stock retirement			(1.5)	1.5
Stock compensation		0.7	55.0
Other comprehensive income (loss)	129.2					129.2
Ending balance at Dec. 31, 2021	11,594.0	347.3	142.0		12,025.8	(921.1)
Net income	3,011.6				3,011.6
Purchases, shares: 2023 - .05; 2022 - .04; 2021 - .02				(2.1)
Cash dividends declared on common stock, per share: 2023 - $4.24; 2022 - $2.80; 2021 - $1.89					(1,461.0)
Treasury stock retirement			(2.1)	2.1
50% stock dividend		174.0			(174.0)
Stock compensation		0.7	56.2
Other comprehensive income (loss)	(32.3)					(32.3)
Ending balance at Dec. 31, 2022	13,167.1	522.0	196.1		13,402.4	(953.4)
Net income	4,600.8				4,600.8
Purchases, shares: 2023 - .05; 2022 - .04; 2021 - .02				(3.5)
Cash dividends declared on common stock, per share: 2023 - $4.24; 2022 - $2.80; 2021 - $1.89					(2,222.9)
Treasury stock retirement			(3.5)	$ 3.5
Stock compensation		1.3	76.5
Other comprehensive income (loss)	259.5					259.5
Ending balance at Dec. 31, 2023	$ 15,878.8	$ 523.3	$ 269.1		$ 15,780.3	$ (693.9)