Capital Accounts, Issuances of Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Net Cash Proceeds from Sale of Common Units [Abstract]
Common units issued in connection with the vesting of phantom unit awards, net (in units)	4,679,377
Buyback Program:
Total of common units repurchased under a buyback program (in units)	1,386,835
Common units acquired in connection with buyback program	$ 40	$ 17
Long-Term Incentive Plan (2008) [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Common units issued in connection with the vesting of phantom unit awards, net (in units)	4,679,377
2019 Buyback Program [Member]
Buyback Program:
Amount authorized under 2019 Buyback Program	$ 2,000
Remaining available capacity under the 2019 Buyback Program	$ 1,000
Total of common units repurchased under a buyback program (in units)	1,386,835	682,589
Common units acquired in connection with buyback program	$ 40	$ 17
At-the-Market Registration [Member]
Registration Statements and Equity Offerings [Line Items]
Maximum common units authorized for issuance	2,500
Remaining units available for issuance	2,500
Employee Unit Purchase Plan [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Employer contribution to EUPP	$ 1
Distribution Reinvestment and Employee Unit Purchase Plans [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Number of common units purchased on the open market and delivered to participants (in units)	1,598,778