Share Plans (Tables)

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Share-based Compensation Expense

Total share-based compensation expense for the three and six months ended June 30, 2020 and 2019 was as follows:

	Three months ended				Six months ended
In millions	June 30, 2020		June 30, 2019		June 30, 2020		June 30, 2019
Restricted stock units	$	3.1	$	2.9	$	6.3	$	5.7
Stock options	0.6		1.1		1.6		2.5
Performance share units	0.5		1.3		2.5		2.5
Total share-based compensation expense	$	4.2	$	5.3	$	10.4	$	10.7

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:

	2020 Annual Grant
Risk-free interest rate	1.61	%
Expected dividend yield	1.80	%
Expected share price volatility	24.1	%
Expected term (years)	6.8