Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense

Components of income tax expense are as follows (in millions):

	Year Ended December 31,
	2023		2022		2021
Current income tax expense:
State income tax	$	2	$	1	$	2
Canadian federal and provincial income tax	143		83		48
Total current income tax expense	$	145	$	84	$	50
Deferred income tax expense/(benefit):
Canadian federal and provincial income tax	$	(24)	$	105	$	23
Total deferred income tax expense/(benefit)	$	(24)	$	105	$	23
Total income tax expense	$	121	$	189	$	73

Schedule of Differences Between Tax Expense based on the Statutory Federal Income Tax Rate and the Effective Income Tax Expense

The difference between income tax expense based on the statutory federal income tax rate and our effective income tax expense is summarized as follows (in millions):

	Year Ended December 31,
	2023		2022		2021
Income before tax	$	1,623	$	1,417	$	721
Partnership earnings not subject to Canadian tax	(1,136)		(686)		(370)
	$	487	$	731	$	351
Canadian federal and provincial corporate tax rate	24%		24%		24%
Income tax expense at statutory rate	$	117	$	175	$	84
Canadian permanent differences	$	2	$	13	$	(13)
State income tax	2		1		2
Total income tax expense	$	121	$	189	$	73

Schedule of Deferred Tax Assets and Liabilities

Deferred tax assets and liabilities are aggregated by the applicable tax paying entity and jurisdiction and result from the following (in millions):

	December 31,
	2023		2022
Deferred tax assets:
Lease liabilities	$	40	$	45
Other	45		16
Total deferred tax assets	85		61
Deferred tax liabilities:
Property and equipment in excess of tax values	(573)		(515)
Derivative instruments	(6)		(46)
Lease assets	(38)		(42)
Other	(3)		(3)
Total deferred tax liabilities	(620)		(606)
Net deferred tax liabilities	$	(535)	$	(545)
Balance sheet classification of deferred tax assets/(liabilities):
Other long-term liabilities and deferred credits	$	(535)	$	(545)
	$	(535)	$	(545)