Other long-term liabilities:



As at	Dec 31 2018			Dec 31 2017
Site restoration costs^(a)	$	27,638		$	33,975
Finance lease obligations^(b)	198,374			204,242
Share-based compensation liability (note 13)	52,794			111,405
Cash flow hedges (note 18)	105,721			90,199
Defined benefit pension plans (note 20)	24,783			25,076
Land mortgage	30,242			—
Other	4,692			5,214
	444,244			470,111
Less current maturities	(46,146		)	(65,226		)
	$	398,098		$	404,885

a) Site restoration costs:

The Company has accrued liabilities related to the decommissioning and reclamation of its methanol production sites and oil and gas properties. Because of uncertainties in estimating the amount and timing of the expenditures related to the sites, actual results could differ from the amounts estimated. As at December 31, 2018, the total undiscounted amount of estimated cash flows required to settle the liabilities was $37.6 million (2017 - $44.9 million). The movement in the provision during the year is explained as follows:



	2018			2017
Balance at January 1	$	33,975		$	30,512
New or revised provisions	(7,036		)	2,823
Accretion expense	699			640
Balance at December 31	$	27,638		$	33,975

b) Finance lease obligations:

As at December 31, 2018, the Company has finance lease obligations related to a methanol terminal and storage tanks in Geismar, Louisiana, an oxygen production facility in Trinidad, and two ocean-going vessels. Total finance lease payments for 2018 of $32.1 million include an interest component of $23.8 million.

Finance lease obligations are payable as follows:



	Lease payments		Interest component		Finance lease obligations
2019	$	32,222	$	22,990	$	9,232
2020	32,614		22,001		10,613
2021	33,014		20,837		12,177
2022	33,422		19,473		13,949
2023	32,779		17,915		14,864
Thereafter	206,223		68,684		137,539
	$	370,274	$	171,900	$	198,374