Stock Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Assumptions Used in Determining Fair Value of Option Awards

The assumptions used in determining the fair value of the option awards for each of the grant years are as follows:

		2023			2022			2021
Risk-free interest rate		3.84	%		1.86	%		.71	%
Expected volatility		26	%		26	%		26	%
Expected dividend yield		4.5	%		4.3	%		3.6	%
Expected term	6 years			6 years			6 years
Weighted average grant date fair value of options per share	$	13.17		$	9.70		$	9.48

Activity Under Company's Stock Plans

A summary of activity under the Company’s stock plans is presented below:

		2023		2022		2021
Intrinsic value of options exercised	$	41.2	$	17.8	$	25.4
Cash received from stock option exercises		51.7		35.8		38.4
Tax benefit related to stock award exercises		5.4		2.6		4.9
Stock-based compensation		21.2		17.1		14.7
Tax benefit related to stock-based compensation		1.7		1.7		1.6

Stock Option Activity

The summary of options as of December 31, 2023 and changes during the year then ended are presented below:

				PER SHARE		REMAINING		AGGREGATE
	NUMBER			EXERCISE		CONTRACTUAL		INTRINSIC
	OF SHARES			PRICE*		LIFE IN YEARS*		VALUE
Options outstanding at January 1		4,205,200		$	51.10
Granted		898,100			72.00
Exercised		(1,174,400	)		44.08
Cancelled		(105,600	)		66.09
Options outstanding at December 31		3,823,300		$	57.77		6.64	$	152.5
Vested and expected to vest		3,678,800		$	57.34		6.55	$	148.3
Exercisable		1,498,400		$	45.45		4.25	$	78.2

* Weighted Average

Nonvested Restricted Shares Activity

The fair value of restricted shares is determined based upon the stock price on the date of grant. The summary of nonvested restricted shares as of December 31, 2023 and changes during the year then ended is presented below:

	NUMBER			GRANT DATE
NONVESTED SHARES	OF SHARES			FAIR VALUE*
Nonvested awards outstanding at January 1		241,500		$	59.69
Granted		197,000			71.27
Vested		(168,700	)		63.06
Forfeited		(8,000	)		60.25
Nonvested awards outstanding at December 31		261,800		$	66.21

* Weighted Average

Dilutive and Antidilutive Options

The dilutive and antidilutive options are shown separately in the table below:

Year Ended December 31,	2023	2022	2021
Additional shares	1,099,000	769,100	973,300
Antidilutive options	891,500	1,653,600	883,800