Debt - Credit Facilities, Borrowings and Repayments and Letters of Credit (Details) - USD ($) $ in Millions		6 Months Ended
	Jan. 31, 2023	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Debt
Repayments of senior notes		$ 400	$ 750
Outstanding letters of credit		127		$ 102
2.85% senior notes due January 2023 | Senior notes
Debt
Debt instrument, interest rate (as a percent)	2.85%			2.85%
Repayments of senior notes	$ 400
Credit facilities and PAA commercial paper program
Debt
Total borrowings		1,500	16,400
Total repayments		$ 1,500	$ 16,300