Income Taxes - Reconciliation and Deferred Tax Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Examination [Line Items]
Income/(loss) before tax	$ 1,417	$ 721	$ (2,599)
Partnership (earnings)/loss not subject to current Canadian tax	(686)	(370)	2,221
Partnership earnings subject to current Canadian tax	$ 731	$ 351	$ (378)
Canadian federal and provincial corporate tax rate	24.00%	24.00%	24.00%
Income tax expense/(benefit) at statutory rate	$ 175	$ 84	$ (91)
Canadian permanent differences and rate changes	13	(13)	72
State income tax	1	2	0
Total income tax expense/(benefit)	189	73	$ (19)
Deferred tax assets:
Derivative instruments	0	39
Lease liabilities	45	48
Net operating losses	0	2
Other	16	17
Total deferred tax assets	61	106
Deferred tax liabilities:
Property and equipment in excess of tax values	(515)	(531)
Derivative instruments	(46)	0
Lease assets	(42)	(47)
Other	(3)	(3)
Total deferred tax liabilities	(606)	(581)
Net deferred tax liabilities	(545)	(475)
Other long-term assets, net
Deferred tax liabilities:
Other long-term assets, net	0	2
Other long-term liabilities and deferred credits
Deferred tax liabilities:
Other long-term liabilities and deferred credits	$ (545)	$ (477)