Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2019

Other Provisions, Contingent Liabilities And Contingent Assets [Abstract]

Change in asset retirement obligations

	December 31, 2019		December 31, 2018
Balance, beginning of year	$	646,898	$	368,995
Liabilities incurred	21,748		12,537
Liabilities settled	(15,417)		(14,035)
Liabilities assumed from corporate acquisition (note 4)	—		39,960
Liabilities acquired from property acquisitions	1,648		132
Liabilities divested	(1,331)		(580)
Property swaps	792		—
Accretion (note 18)	13,713		10,914
Change in estimate(1)	19,632		33,453
Changes in discount rates and inflation rates	(17,486)		192,672
Foreign currency translation	(2,223)		2,850
Balance, end of year	$	667,974	$	646,898
Less current portion of asset retirement obligations	11,579		—
Non-current portion of asset retirement obligations	$	656,395	$	646,898

(1)Changes in the estimated costs, the timing of abandonment and reclamation and the status of wells are factors resulting in a change in estimate.