Environmental and other provisions (Tables)

12 Months Ended

Dec. 31, 2025

Disclosure of other provisions [abstract]

Disclosure of detailed information about changes in provisions [Table Text Block]

		Decommis- sioning, restoration and similar liabilities			Deferred share units³			Restricted share units^{1, 3}			Performance share units³			Other²			Total
Balance, January 1, 2025	$	296.9		$	12.3		$	9.6		$	5.5		$	6.4		$	330.7
Net change in provision		26.2			0.9			11.5			16.0			9.5			64.1
Disbursements		(1.7	)		(5.4	)		(6.3	)		(3.5	)		(0.9	)		(17.8	)
Reduction of obligation to renounce flow-through share expenditures, net of provisions		-			-			-			-			(5.5	)		(5.5	)
Unwinding of discount (note 6h)		11.1			-			-			-			-			11.1
Effect of change in discount rate		(25.9	)		-			-			-			-			(25.9	)
Effect of foreign exchange		11.8			0.7			0.3			0.3			0.4			13.5
Effect of change in share price		-			13.0			11.0			8.6			-			32.6
Balance, December 31, 2025	$	318.4		$	21.5		$	26.1		$	26.9		$	9.9		$	402.8

		Decommis- sioning, restoration and similar liabilities			Deferred share units³			Restricted share units^1,3			Performan- ce share units³			Other²			Total
Balance, January 1, 2024	$	315.4		$	8.7		$	5.0		$	2.6		$	12.5		$	344.2
Net additional provisions made		14.5			1.1			5.6			3.1			0.8			25.1
Disbursements		(2.1	)		(1.6	)		(2.2	)		(0.9	)		(4.8	)		(11.6	)
Reduction of obligation to renounce flow-through share-expenditures, net of provisions		-			-			-			-			(2.0	)		(2.0	)
Unwinding of discount (note 6h)		10.5			-			-			-			-			10.5
Effect of change in discount rate		(22.7	)		-			-			-			-			(22.7	)
Effect of foreign exchange		(18.7	)		(1.1	)		(0.5	)		(0.4	)		(0.1	)		(20.8	)
Effect of change in share price		-			5.2			1.7			1.1			-			8.0
Balance, December 31, 2024	$	296.9		$	12.3		$	9.6		$	5.5		$	6.4		$	330.7

Disclosure of detailed information about provisions [Table Text Block]

December 31, 2025

Decommis-

sioning,

restoration

and similar

liabilities

Deferred

share units

Restricted

share units

Performance

share units

Other

Total

Current (note 16)

$

20.6

$

21.5

$

20.5

$

19.0

$

8.6

$

90.2

Non-current

297.8

-

5.6

7.9

1.3

312.6

$

318.4

$

21.5

$

26.1

$

26.9

$

9.9

$

402.8

December 31, 2024		Decommis- sioning, restoration and similar liabilities			Deferred share units			Restricted share units			Performance share units			Other			Total
Current (note 16)	$	4.0		$	12.3		$	6.4		$	1.9		$	5.3		$	29.9
Non-current		292.9			-			3.2			3.6			1.1			300.8
	$	296.9		$	12.3		$	9.6		$	5.5		$	6.4		$	330.7