Income and mining taxes (Tables)

12 Months Ended

Dec. 31, 2020

Major components of tax expense (income) [abstract]

Disclosure of detailed information about effective income tax expense recovery [Table Text Block]

		Year ended December 31,
		2020			2019
Current:
Income taxes	$	4,458		$	24,919
Mining taxes		4,671			4,720
Adjustments in respect of prior years		(398	)		6,273
		8,731			35,912
Deferred:
Income tax recoveries - origination, revaluation and/or reversal of temporary differences		(39,411	)		(133,468	)
Mining tax recoveries - origination, revaluation and/or reversal of temporary difference		(3,331	)		(12,214	)
Adjustments in respect of prior years		(494	)		817
		(43,236	)		(144,865	)
	$	(34,505	)	$	(108,953	)

Disclosure of detailed information about deferred taxes [Table Text Block]

		Dec. 31, 2020			Dec. 31, 2019
Deferred income tax asset	$	94,070		$	69,950
Deferred mining tax asset		7,829			5,096
		101,899			75,046
Deferred income tax liability		(220,568	)		(233,218	)
Deferred mining tax liability		(8,865	)		(9,710	)
		(229,433	)		(242,928	)
Net deferred tax liability balance, end of year	$	(127,534	)	$	(167,882	)

Disclosure of detailed information about changes in deferred tax assets and liabilities [Table Text Block]

		Year ended Dec. 31, 2020			Year ended Dec. 31, 2019
Net deferred tax liability balance, beginning of year	$	(167,882	)	$	(308,577	)
Deferred tax recovery		43,236			144,865
OCI transactions		(759	)		1,878
Foreign currency translation on the deferred tax liability		(2,129	)		(6,048	)
Net deferred tax liability balance, end of year	$	(127,534	)	$	(167,882	)

Disclosure of detailed information about reconciliation to statutory tax rate [Table Text Block]

		Year ended December 31,
		2020			2019
Statutory tax rate		26.3	%		27.0	%
Tax recovery at statutory rate	$	(47,047	)	$	(122,246	)
Effect of:
Deductions related to mining taxes		(1,369	)		(1,493	)
Adjusted income taxes		(48,416	)		(123,739	)
Mining tax expense (recovery)		1,291			(6,674	)
		(47,125	)		(130,413	)
Permanent differences related to:
Capital items		(160	)		3,270
Other income tax permanent differences		(1,165	)		1,747
Impact of remeasurement on decommissioning liability		7,094			(12,018	)
Temporary income tax differences not recognized		(1,827	)		(351	)
Other temporary income tax differences not recognized		2,927			2,323
Non-deductible impairment on UCM receivable		—			7,041
Withholding tax on dividends		—			6,826
Impact related to differences in tax rates in foreign operations		5,534			20,338
Impact of changes to statutory tax rates		2,412			(259	)
Foreign exchange on non-monetary items		(3,628	)		(6,633	)
Impact related to tax assessments and tax return amendments		1,433			(824	)
Tax recovery	$	(34,505	)	$	(108,953	)

Disclosure of temporary differences recognized [Table Text Block]

		Balance sheet						Income Statement
		Dec. 31, 2020			Dec. 31, 2019			Dec. 31, 2020			Dec. 31, 2019
Deferred income tax (liability) asset/expense (recovery)
Property, plant and equipment	$	(88,368	)	$	(96,841	)	$	(8,473	)	$	13,434
Pension obligation		9,467			11,332			1,294			(1,115	)
Other employee benefits		25,687			16,837			(8,850	)		(3,349	)
Decommissioning and restoration obligation		37,902			41,208			3,307			(33,391	)
Non-capital losses		110,374			90,446			(19,928	)		(17,976	)
Share issuance and debt cost		8,972			6,540			(2,768	)		4,361
Embedded derivative (prepayment option)		(13,137	)		(694	)		12,443			245
Deferred revenue		(809	)		(112	)		697			(12,839	)
Other		3,982			1,234			(4,516	)		(7,755	)
Deferred income tax asset / expense (recovery)		94,070			69,950			(26,794	)		(58,385	)
Deferred income tax liability (asset)/ (recovery) expense
Property, plant and equipment		292,858			259,145			33,713			(79,892	)
Other employee benefits		203			(80	)		(176	)		(320	)
Asset retirement obligations		(1,588	)		(833	)		(756	)		85
Non-capital losses		(78,607	)		(28,643	)		(49,965	)		(1,269	)
Other		7,702			3,629			4,073			7,302
Deferred income tax liability/ expense (recovery)		220,568			233,218			(13,111	)		(74,094	)
Deferred income tax liability/ expense (recovery)	$	(126,498	)	$	(163,268	)	$	(39,905	)	$	(132,479	)

Disclosure of detailed information about temporary differences not recognized [Table Text Block]

		Dec. 31, 2020		Dec. 31, 2019
Property, plant and equipment	$	46,718	$	33,269
Capital losses		166,227		159,545
Other employee benefits		51,226		68,866
Asset retirement obligations		193,898		146,679
Non-capital losses		115,902		122,979
Temporary differences not recognized	$	573,971	$	531,338

Disclosure of detailed information about temporary differences - deferred mining tax assets and liabilities [Table Text Block]

		Dec. 31, 2020			Dec. 31, 2019
Canada
Property, plant and equipment	$	7,829		$	5,095
		Dec. 31, 2020			Dec. 31, 2019
Peru
Property, plant and equipment	$	(8,865	)	$	(9,710	)