7. MINING INTERESTS

The following table shows the breakdown of the cost, accumulated depreciation and net book value of plant and equipment, mining properties and construction in progress:



	Plant and equipment			Mining properties		Construction in progress			Total
Cost
As of December 31, 2017	479,214			798,433		126,923			1,404,570
Additions	95			677		45,485			46,257
Transfers	16,516			127,902		(144,418		)	—
Capitalized interest	—			—		579			579
Change in rehabilitation provision estimate	—			3,218		—			3,218
Disposals and other	(17,065		)	—		—			(17,065		)
Balance at December 31, 2018	$	478,760		$	930,230	$	28,569		$	1,437,559
Additions	2,869			288		72,615			75,772
Transfers	11,586			71,337		(82,923		)	—
Change in rehabilitation provision estimate	—			4,830		—			4,830
Disposals and other	(621		)	—		—			(621		)
Balance at December 31, 2019	$	492,594		$	1,006,685	$	18,261		$	1,517,540

Accumulated depreciation
As of December 31, 2017	437,292			713,220		—			1,150,512
Depreciation and amortization	12,349			20,900		—			33,249
Disposals and other	(16,842		)	—		—			(16,842		)
Balance at December 31, 2018	$	432,799		$	734,120	$	—		$	1,166,919
Depreciation and amortization	10,582			19,044		—			29,626
Disposals and other	(456		)	—		—			(456		)
Impairment charges (see Note 19)	7,338			49,424		—			56,762
Balance at December 31, 2019	$	450,263		$	802,588	$	—		$	1,252,851

Carrying amount
Balance at December 31, 2018	$	45,961		$	196,110	$	28,569		$	270,640
Balance at December 31, 2019	$	42,331		$	204,097	$	18,261		$	264,689

Additions to plant and equipment include right-of-use assets related to the Company's corporate office space. As at December 31, 2019, the right-of-use assets had net carrying amounts of $3.3 million (December 31, 2018 - $3.0 million). The total minimum lease payments are disclosed in Note 12 - Debt.