Share Plans (Tables)

9 Months Ended

Sep. 30, 2022

Share-based Payment Arrangement [Abstract]

Share-based Compensation Expense

Total share-based compensation expense for the three and nine months ended September 30, 2022 and 2021 was as follows:

	Three months ended				Nine months ended
In millions	September 30, 2022		September 30, 2021		September 30, 2022		September 30, 2021
Restricted stock units	$	4.1	$	2.4	$	11.0	$	9.4
Stock options	1.1		0.7		3.0		2.5
Performance share units	2.2		1.1		6.6		8.9
Total share-based compensation expense	$	7.4	$	4.2	$	20.6	$	20.8

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

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:

	2022 Annual Grant
Risk-free interest rate	1.18	%
Expected dividend yield	1.14	%
Expected share price volatility	29.60	%
Expected term (years)	6.4