Share Capital (Tables)

12 Months Ended

Dec. 31, 2024

Equity [Abstract]

Schedule of common stock outstanding roll forward

Common shares

In millions	As at December 31,	2024	2023	2022
Issued common shares		628.8	643.8	672.4
Common shares in Share Trusts		(0.9)	(1.1)	(1.4)
Outstanding common shares		627.9	642.7	671.0

Schedule of activity under share repurchase programs

In millions, except per share data	Year ended December 31,	2024		2023		2022
Number of common shares repurchased		15.4		29.1		30.2
Weighted-average price per share (1)		$	172.07	$	156.37	$	156.00
Amount of repurchase (1)		$	2,651	$	4,551	$	4,709

(1)Includes brokerage fees and tax on share repurchases.

Schedule of activity of purchases and settlements by share trusts

Share purchases

In millions, except per share data	Year ended December 31,	2024		2023		2022
Share purchases by Share Units Plan Share Trusts
Number of common shares		0.1		—		0.5
Weighted-average price per share		$	173.49	$	—	$	170.85
Amount of purchase		$	20	$	—	$	81
Share purchases by ESIP Share Trusts
Number of common shares		0.2		0.2		0.2
Weighted-average price per share		$	163.11	$	156.89	$	155.53
Amount of purchase		$	30	$	28	$	24
Total purchases		$	50	$	28	$	105

Share settlements

In millions, except per share data	Year ended December 31,	2024		2023		2022
Share settlements by Share Units Plan Share Trusts
Number of common shares		0.3		0.3		0.2
Weighted-average price per share		$	127.87	$	122.08	$	88.23
Amount of settlement		$	37	$	31	$	15
Share settlements by ESIP Share Trusts
Number of common shares		0.2		0.2		0.2
Weighted-average price per share		$	157.51	$	151.32	$	141.60
Amount of settlements		$	28	$	23	$	23
Total settlements		$	65	$	54	$	38