Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments And Contingencies [Abstract]

Schedule of minimum estimated commitment under purchase contracts

The minimum estimated commitment under these contracts, except as noted below, is as follows:

As at December 31, 2017



2018		2019		2020		2021		2022		Thereafter
$	473,927	$	371,167	$	306,400	$	308,338	$	245,989	$	1,300,609

Schedule of minimum lease payments

Finance lease obligations are payable as follows:



	Lease payments		Interest component		Finance lease obligations
2018	$	31,447	$	23,549	$	7,898
2019	31,826		22,727		9,099
2020	32,213		21,756		10,457
2021	32,608		20,612		11,996
2022	33,010		19,271		13,739
Thereafter	236,772		85,719		151,053
	$	397,876	$	193,634	$	204,242

The Company has future minimum lease payments under operating leases relating primarily to vessel charter, terminal facilities, office space, equipment and other operating lease commitments as follows:

As at December 31, 2017



2018		2019		2020		2021		2022		Thereafter
$	90,820	$	90,035	$	56,973	$	38,982	$	37,858	$	163,822