Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property, plant and equipment [abstract]

Schedule of property, plant and equipment

	Buildings, plant installations and machinery			Finance leases		Ocean going vessels			Other			TOTAL
Cost at January 1, 2018	$	4,648,924		$	215,773	$	144,423		$	131,070		$	5,140,190
Additions	180,437			2,037		40,284			58,349			281,107
Disposals and other	(131,219		)	—		(1,288		)	(361		)	(132,868		)
Cost at December 31, 2018	4,698,142			217,810		183,419			189,058			5,288,429
Accumulated depreciation at January 1, 2018	1,956,317			33,927		40,427			111,193			2,141,864
Disposals and other	(124,920		)	—		(1,194		)	(360		)	(126,474		)
Depreciation	216,338			16,054		9,193			6,359			247,944
Accumulated depreciation at December 31, 2018	2,047,735			49,981		48,426			117,192			2,263,334
Net book value at December 31, 2018	$	2,650,407		$	167,829	$	134,993		$	71,866		$	3,025,095

	Buildings, plant installations and machinery			Finance leases		Ocean going vessels			Other			TOTAL
Cost at January 1, 2017	$	4,549,816		$	206,260	$	145,303		$	127,575		$	5,028,954
Additions	98,780			7,667		605			4,396			111,448
Disposals and other	328			1,846		(1,485		)	(901		)	(212		)
Cost at December 31, 2017	4,648,924			215,773		144,423			131,070			5,140,190
Accumulated depreciation at January 1, 2017	1,752,540			18,557		31,135			109,253			1,911,485
Disposals and other	(2,066		)	—		—			(673		)	(2,739		)
Depreciation	205,843			15,370		9,292			2,613			233,118
Accumulated depreciation at December 31, 2017	1,956,317			33,927		$	40,427		111,193			2,141,864
Net book value at December 31, 2017	$	2,692,607		$	181,846	$	103,996		$	19,877		$	2,998,326