Pension obligations (Tables)

12 Months Ended

Dec. 31, 2017

Statement [Line Items]

Disclosure of additional information about defined benefit plans [Table Text Block]

		Year ended
		December 31,
		2017			2016
Opening defined benefit obligation	$	349,165		$	337,004
Current service cost		10,707			10,768
Past service cost related to the new collective bargaining agreement		10,442			-
Interest cost		12,602			13,415
Benefits paid from plan		(33,721	)		(32,644	)
Benefits paid from employer		(999	)		(1,424	)
Participant contributions		93			93
Effects of movements in exchange rates		24,440			10,348
Remeasurement actuarial (gains)/losses:
Arising from changes in demographic assumptions		1,598			-
Arising from changes in financial assumptions		9,402			14,955
Arising from experience adjustments		(675	)		(3,350	)
Closing defined benefit obligation	$	383,054		$	349,165

Disclosure of additional information about defined benefit plans, balance by member group [Table Text Block]

		Dec. 31, 2017		Dec. 31, 2016
Active members	$	250,965	$	235,815
Deferred members		4,304		3,636
Retired members		127,785		109,714
Closing defined benefit obligation	$	383,054	$	349,165

Disclosure of changes in fair value of plan assets [Table Text Block]

		Year ended
		December 31,
		2017			2016
Opening fair value of plan assets:	$	296,151		$	279,523
Interest income		11,005			11,634
Remeasurements losses:
Return on plan assets (excluding amounts included in net interest expense)		24,437			2,905
Contributions from the employer		22,484			26,198
Employer direct benefit payments		999			1,424
Contributions from plan participants		93			93
Benefit payment from employer		(999	)		(1,424	)
Administrative expenses paid from plan assets		(80	)		(77	)
Benefits paid		(33,721	)		(32,644	)
Effects of changes in foreign exchange rates		21,063			8,519
Closing fair value of plan assets	$	341,432		$	296,151

Disclosure of net defined benefit liability (asset) [Table Text Block]

		Dec. 31, 2017			Dec. 31, 2016
Present value of funded defined benefit obligation	$	365,655		$	333,720
Fair value of plan assets		(341,432	)		(296,151	)
Present value of unfunded defined benefit obligation		17,399			15,445
Net liability arising from defined benefit obligation	$	41,622		$	53,014

Disclosure of detailed information about pension obligation [Table Text Block]

		Dec. 31, 2017		Dec. 31, 2016
Pension obligation - current (note 13)	$	19,401	$	24,635
Pension obligation - non-current		22,221		28,379
Total pension obligation	$	41,622	$	53,014

Disclosure of detailed information about pension expense [Table Text Block]

		Dec. 31, 2017		Dec. 31, 2016
Service costs:
Current service cost	$	10,707	$	10,768
Past service cost and loss from settlements		10,442		-
Total service cost		21,149		10,768
Net interest expense		1,597		1,781
Administration cost		80		77
Defined benefit pension expense	$	22,826	$	12,626
Defined contribution pension expense	$	908	$	829

Disclosure of detailed information about remeasurement on the net defined benefit liability [Table Text Block]

		Dec. 31, 2017			Dec. 31, 2016
(Return)/loss on plan assets (excluding amounts included in net interest expense)	$	(24,437	)	$	(2,905	)
Actuarial gains arising from changes in demographic assumptions		1,598			-
Actuarial losses/(gains) arising from changes in financial assumptions		9,402			14,955
Actuarial gains arising from experience adjustments		(675	)		(3,350	)
Defined benefit loss/(gain) related to remeasurement	$	(14,112	)	$	8,700
Total pension cost	$	9,622		$	22,155

Disclosure of defined benefit plan, assumptions used [Table Text Block]

	2017	2016
Defined benefit cost:
Discount rate - benefit obligations	3.69 %	4.08%
Discount rate - service cost	3.82 %	4.25%
Expected rate of salary increase 1	2.75 %	3.00%
Average longevity at retirement age for current pensioners (years) 2 :
Males	20.9	20.8
Females	23.3	23.3
	2017	2016
Defined benefit obligation:
Discount rate	3.45 %	3.69%
Expected rate of salary increase 1	2.75 %	2.75%
Average longevity at retirement age for current pensioners (years) 2 :
Males	21.0	20.9
Females	23.7	23.3
Average longevity at retirement age for current employees (future pensioners) (years) 2:
Males	22.9	22.2
Females	25.5	24.5

Disclosure of fair value of plan assets [Table Text Block]

December 31, 2017		Level 1		Level 2		Level 3		Total
Investments:
Money market instruments	$	4,625	$	-	$	-	$	4,625
Pooled equity funds		116,027		-		-		116,027
Pooled fixed income funds		-		189,964		-		189,964
Alternative investment funds		-		30,699		-		30,699
Balanced funds		-		117		-		117
	$	120,652	$	220,780	$	-	$	341,432
December 31, 2016		Level 1		Level 2		Level 3		Total
Investments:
Money market instruments	$	4,515	$	-	$	-	$	4,515
Pooled equity funds		121,103		-		-		121,103
Pooled fixed income funds		-		143,489		-		143,489
Alternative investment funds		-		26,404		-		26,404
Balanced funds		-		640		-		640
	$	125,618	$	170,533	$	-	$	296,151