Capital Accounts - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended			6 Months Ended
	Aug. 14, 2025	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Buyback Program:
Total of common units repurchased and retired under a buyback program (in units)		3,566,979	1,803,215
Cost of common units repurchased under 2019 buyback program		$ 110		$ 40	$ 170	$ 80
Proceeds from Issuance or Sale of Equity [Abstract]
Common units issued in connection with the vesting of phantom unit awards, net (in units)		220,829	4,989,490
Cash distributions paid to convertible preferred unitholders					$ 2
Paid in-kind distribution to third party (in units)		97	95		192
Paid -in-kind unit issued value (less than)					$ 1
Distribution per common unit (in dollars per unit)		$ 0.545
Annualized distribution per common unit (in dollars per unit)		$ 2.18
Cash payments made in connection with DERs					$ 22	$ 21
Forecast
Proceeds from Issuance or Sale of Equity [Abstract]
Cash distributions paid	$ 1,190
Cash payments made in connection with DERs	$ 11
Long-Term Incentive Plan (2008)
Proceeds from Issuance or Sale of Equity [Abstract]
Common units issued in connection with the vesting of phantom unit awards, net (in units)					5,210,319
2019 Buyback Program
Buyback Program:
Amount authorized under 2019 Buyback Program		$ 2,000			$ 2,000
Total of common units repurchased and retired under a buyback program (in units)		3,566,979		1,419,581	5,370,194	2,806,416
Cost of common units repurchased under 2019 buyback program		$ 110		$ 40	$ 170	$ 80
Remaining available capacity under the 2019 Buyback Program		692			692
At-the-Market Registration
Registration Statements and Equity Offerings [Line Items]
Maximum common units authorized for issuance		2,500			2,500
Remaining units available for issuance		$ 2,500			$ 2,500
Distribution Reinvestment and Employee Unit Purchase Plans
Proceeds from Issuance or Sale of Equity [Abstract]
Number of common units purchased on the open market and delivered to participants (in units)					2,366,556
Employee Unit Purchase Plan
Proceeds from Issuance or Sale of Equity [Abstract]
Employer contribution to EUPP					$ 2