Share Plans (Tables)

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Share-based Compensation Expense

Total share-based compensation expense for the three months ended March 31, 2022 and 2021 was as follows:

	Three months ended
In millions	March 31, 2022		March 31, 2021
Restricted stock units	$	3.6	$	3.4
Stock options	1.0		0.9
Performance share units	2.3		1.3
Total share-based compensation expense	$	6.9	$	5.6

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