Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Share-Based Compensation Arrangements by Share-Based Payment Award

At December 31, 2022, the Company had total unrecognized stock-based compensation expense of $125.2 million that is expected to be recognized over a weighted-average period of 1.05 years.

	2022		2021		2020
Stock-based compensation expense	$	99.7	$	97.7	$	95.9
Income tax benefit recognized	24.6		24.1		23.6

Weighted-Average Assumptions Used for Estimating the Fair Value of Option Rights

The fair value of the Company’s options was estimated at the date of grant using a Black-Scholes-Merton option-pricing model with the following weighted-average assumptions for all options granted:

	2022		2021		2020
Risk-free interest rate	4.00	%	1.11	%	.39	%
Expected life of options	5.05 years		5.05 years		5.05 years
Expected dividend yield of stock	.92	%	.75	%	.88	%
Expected volatility of stock	31.6	%	26.8	%	26.7	%

Summary of Non-Qualified and Incentive Stock Option Right Activity

The following table summarizes the Company’s option activity:

	Optioned Shares	Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value		Weighted Average Remaining Term (in Years)
Outstanding at January 1, 2022	8,982,935	$	147.83	$	1,835.5	6.09
Granted	1,000,863	220.57
Exercised	(780,677)	86.91
Forfeited	(81,902)	247.92
Expired	(18,581)	182.48
Outstanding at December 31, 2022	9,102,638	$	160.09	$	756.6	5.82
Exercisable at December 31, 2022	7,088,732	$	137.09	$	727.7	4.91

The following table summarizes fair value and intrinsic value information for option activity:

	2022		2021		2020
Weighted average grant date fair value per share	$	69.82	$	68.63	$	46.56
Total fair value of options vested	57.9		53.2		51.0
Total intrinsic value of options exercised	125.4		485.8		407.9

Summary of RSU Activity

The following table summarizes the Company’s RSU activity:

	Number of RSUs	Weighted Average Grant Date Fair Value Per Share		Aggregate Intrinsic Value		Weighted Average Remaining Term (in Years)
Outstanding at January 1, 2022	510,680	$	185.38	$	179.8	0.96
Granted	254,935	271.75
Vested	(357,832)	145.47
Forfeited	(5,859)	225.42
Outstanding at December 31, 2022	401,924	231.09		$	95.4	1.02

The following table summarizes the fair value and intrinsic value information for RSU activity:

	2022		2021		2020
Weighted average grant date fair value per share	$	271.75	$	238.89	$	193.79
Intrinsic value of RSUs vested during year	97.5		66.3		75.0