Asset retirement obligations (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Asset Retirement Obligations [abstract]


	Turkey		Canada		Greece		Romania		Brazil (1)		Total

At January 1, 2020	$	39,196	$	12,638	$	42,650	$	1,533	$	—	$	96,017

Accretion during the year	753		243		863		34		52		1,945
Revisions to estimate	5,539		80		10,056		94		—		15,769
Settlements	(672)		—		(1,629)		—		—		(2,301)
Disposal	—		—		—		—		(52)		(52)

At December 31, 2020	$	44,816	$	12,961	$	51,940	$	1,661	$	—	$	111,378
Less: Current portion	—		—		(4,701)		—		—		(4,701)
Long term portion	$	44,816	$	12,961	$	47,239	$	1,661	$	—	$	106,677

Estimated undiscounted amount	$	56,752	$	14,218	$	65,564	$	2,153	$	—	$	138,687

(1) The asset retirement obligation related to the Vila Nova mine was included in liabilities associated with assets held for sale at December 31, 2019 and disposed of in 2020 (Note 32)


	Turkey		Canada		Greece		Romania		Brazil		Total

At January 1, 2019	$	36,479	$	12,215	$	40,069	$	1,364	$	4,016	$	94,143

Accretion during the year	981		316		1,090		39		106		2,532
Revisions to estimate	2,330		107		3,704		130		—		6,271
Settlements	(594)		—		(2,213)		—		—		(2,807)
Reclassified to liabilities associated with assets held for sale	—		—		—		—		(4,122)		(4,122)
At December 31, 2019	$	39,196	$	12,638	$	42,650	$	1,533	$	—	$	96,017
Less: Current portion	—		—		(1,782)		—		—		(1,782)
Long term portion	$	39,196	$	12,638	$	40,868	$	1,533	$	—	$	94,235

Estimated undiscounted amount	$	48,064	$	14,998	$	56,467	$	2,287	$	4,416	$	126,232

Summary of present value of estimated future net cash outflows

The provision is calculated as the present value of estimated future net cash outflows based on the following key assumptions:


	Turkey	Canada	Greece	Romania	Brazil
	%	%	%	%	%
At December 31, 2020
Inflation rate	0.7 to 1.5	0.9	0.4 to 1.7	1.5	—
Discount rate	0.7 to 1.5	0.9	0.4 to 1.7	1.5	—

At December 31, 2019
Inflation rate	1.8	1.8	1.7 to 1.9	1.9	1.6
Discount rate	1.9	1.9	1.7 to 2.3	2.3	1.6