Capital Accounts, Issuances of Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Net Cash Proceeds from Sale of Common Units [Abstract]
Common units issued in connection with the vesting of phantom unit awards, net (in units)	4,989,490
Buyback Program:
Total of common units repurchased under a buyback program (in units)	1,803,215
Common units acquired in connection with buyback program	$ 60	$ 40
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)	4,989,490
2019 Buyback Program [Member]
Buyback Program:
Amount authorized under 2019 Buyback Program	$ 2,000
Remaining available capacity under the 2019 Buyback Program	$ 803
Total of common units repurchased under a buyback program (in units)	1,803,215	1,386,835
Common units acquired in connection with buyback program	$ 60	$ 40
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)	1,063,842