Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2021

Environmental Remediation Obligations [Abstract]

Changes in Reserve for Environmental Remediation and Asset Retirement Obligations

The following table reflects changes in the reserve for environmental remediation and asset retirement obligations:

	March 31, 2021
	$
Balance at beginning of year		47
Additions and other changes		1
Environmental spending		(1	)
Balance at end of period		47