Mineral Property, Pland and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Amortization rates applicable to each category of property, plant and equipment, with the exception of land, are as follows:


Asset			Useful life
Leasehold improvements			Lease term
Mobile equipment			2-10 years
Other equipment			2-20 years
Processing plant			Unit-of-production
Shaft, underground infrastructure and mineral properties			Unit-of-production
Vehicles			3-7 years
Buildings			7-20 years
Office equipment			2-8 years


		Mineral property
	Plant and equipment	Depletable	Non-depletable	Exploration and evaluation	Total
Cost
At December 31, 2018	$1,194.6	$2,305.6	$95.8	$250.4	$3,846.4
Additions	125.2	131.9	9.1	11.6	277.8
Revisions to decommissioning liabilities	—	13.3	—	—	13.3
Right-of-use assets	2.4	—	—	—	2.4
Disposals	(1.9)	—	—	—	(1.9)
At December 31, 2019	$1,320.3	$2,450.8	$104.9	$262.0	$4,138.0
Additions	94.1	101.5	33.2	14.2	243.0
Acquisition of Trillium Mining Corp. (i)	—	—	—	19.3	19.3
Repurchase of Island Gold royalty (ii)	—	54.8	—	—	54.8
Revisions to decommissioning liabilities	—	17.1	—	—	17.1
Disposals	(5.6)	—	—	—	(5.6)
Transfers	121.2	—	(121.2)	—	—
At December 31, 2020	$1,530.0	$2,624.2	$16.9	$295.5	$4,466.6

Accumulated amortization and impairment charges
At December 31, 2018	$502.9	$521.4	$—	$8.8	$1,033.1
Amortization	66.6	105.0	—	—	171.6
Amortization (right-of-use assets)	1.1	—	—	—	1.1
Disposals	(1.2)	—	—	—	(1.2)
At December 31, 2019	$569.4	$626.4	$—	$8.8	$1,204.6
Amortization	75.5	88.8	—	—	164.3
Amortization (right-of-use assets)	1.0	—	—	—	1.0
Disposals	(4.6)	—	—	—	(4.6)

At December 31, 2020	$641.3	$715.2	$—	$8.8	$1,365.3

Net carrying value
At December 31, 2019	$750.9	$1,824.4	$104.9	$253.2	$2,933.4
At December 31, 2020	$888.7	$1,909.0	$16.9	$286.7	$3,101.3

Note: Certain comparative balances have been restated to conform presentation adopted during the year.

The net carrying values by segment (note 14) are as follows: