Share-Based Compensation

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Total share-based compensation expense for the three months ended March 31, 2024 and 2023, was as follows:


	Three months ended
In millions	March 31, 2024		March 31, 2023
Restricted stock units	$	3.3	$	2.7
Performance share units	2.0		2.0
Stock options	1.3		1.0
Total	$	6.6	$	5.7

In the first quarter of 2024, we issued our annual share-based compensation grants under the 2018 Omnibus Incentive Plan to eligible employees. The total number of awards issued was approximately 0.6 million, of which 0.2 million were restricted stock units ("RSUs"), 0.1 million were performance share units ("PSUs") and 0.3 million were stock options. The weighted-average grant date fair value of the RSUs, PSUs and stock options issued was $68.74, $103.93 and $27.16, respectively.

We estimated the fair value of each stock option award issued in the annual share-based compensation grant using a Black-Scholes option pricing model, modified for dividends, and using the following assumptions:


	2024 Annual Grant
Risk-free interest rate	4.06	%
Expected dividend yield	1.27	%
Expected share price volatility	37.1	%
Expected term (years)	6.8

These estimates require us to make assumptions based on historical results, observance of trends in our share price, changes in option exercise behaviors, future expectations and other relevant factors. If other assumptions had been used, share-based compensation expense, as calculated and recorded under the accounting guidance, could have been affected.

We based the expected life assumption on historical experience as well as the terms and vesting periods of the options granted. For purposes of determining expected volatility, we considered historical volatilities of peer companies over a period approximately equal to the expected option term. The risk-free rate for periods that coincide with the expected life of the options is based on the U.S. Treasury Department yield curve in effect at the time of grant.