LEASES (Tables)

12 Months Ended

Dec. 31, 2020

LEASES

Summary of carrying amounts of right-of-use assets

	As at December 31,		As at December 31,
	2020		2019
Balance, beginning of year	$	117,581	$	83,743
Additions and modifications, net of disposals		9,688		46,822
Amortization		(14,554)		(12,984)
Balance, end of year	$	112,715	$	117,581

Summary of lease obligations included in the consolidated balance sheets

	As at December 31,		As at December 31,
	2020		2019
Current	$	20,852	$	14,693
Non-current		99,423		102,135
Total lease obligations	$	120,275	$	116,828

Summary of future minimum lease payments required to meet obligations that have initial or remaining non-cancellable lease terms

	As at December 31,		As at December 31,
	2020		2019
Within 1 year	$	20,464	$	16,641
Between 1 - 3 years		28,090		31,220
Between 3 - 5 years		17,846		19,189
Thereafter		57,301		62,587
Total undiscounted lease obligations	$	123,701	$	129,637

Summary of amounts recognized in consolidated statements of income (loss) with respect to leases

	Year Ended December 31,
	2020		2019
Amortization of right-of-use assets	$	14,554	$	12,984
Interest expense on lease obligations	$	1,997	$	1,909
Variable lease payments not included in the measurement of lease obligations	$	117,317	$	106,909
Expenses relating to short-term leases	$	4,926	$	3,595
Expenses relating to leases of low value assets, excluding short-term leases of low value assets	$	792	$	1,071