Asset retirement obligations (Tables)

12 Months Ended

Dec. 31, 2017


	Greece			Brazil			Turkey			Romania		Canada		Total
	$			$			$			$		$		$
At January 1, 2017		48,131			4,092			36,196			1,359		-		89,778
Acquired during the year		-			-			-			-		9,453		9,453
Accretion during the year		1,025			32			913			36		-		2,006
Revisions to estimate of obligation		1,112			(80	)		502			10		-		1,544
Settlements		(2,807	)		-			(290	)		-		-		(3,097	)
At December 31, 2017		47,461			4,044			37,321			1,405		9,453		99,684
Less: Current portion		(3,489	)		-			-			-		-		(3,489	)
Long term portion		43,972			4,044			37,321			1,405		9,453		96,195
Estimated undiscounted amount		71,591			4,117			49,257			2,340		12,286		139,591

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

Greece

Brazil

Turkey

Romania

Canada

At December 31, 2016

Inflation rate

2.0 to 2.4

Discount rate

1.5 to 3.0

0.8

2.3 to 2.5

2.7

At December 31, 2017

Inflation rate

2.0 to 2.2

Discount rate

1.5 to 3.0

1.8

2.3 to 2.5

2.7

2.3 to 2.5