Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2019

Supplemental Cash Flow Elements [Abstract]

Schedule of Cash, Cash Equivalents, and Restricted Cash

Total cash, cash equivalents, restricted cash, and cash and restricted cash held for sale are as follows:

	December 31, 2019	December 31, 2018	December 31, 2017
	$	$	$
Cash and cash equivalents	353,241	424,169	445,452
Restricted cash – current	56,777	40,493	38,179
Restricted cash – non-current	44,849	40,977	68,543
Assets held for sale - cash	1,121	—	—
Assets held for sale - restricted cash	337	—	—
	456,325	505,639	552,174

Changes in Operating Assets and Liabilities

The changes in operating assets and liabilities for the years ended December 31, 2019, 2018, and 2017, are as follows:

	Year Ended December 31,
	2019		2018		2017
Accounts receivable	(38,811	)	(25,090	)	(1,925	)
Prepaid expenses and other	(103,712	)	(30,808	)	3,118
Accounts payable	104,579		8,929		(14,499	)
Accrued liabilities and other	33,121		32,215		118,137
	(4,823	)	(14,754	)	104,831