Capital Accounts, Issuances of Equity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2022	Jun. 30, 2021
Net Cash Proceeds from Sale of Common Units [Abstract]
Common units issued in connection with the vesting of phantom unit awards, net (in units)	204,357	4,051,207
Buyback Program:
Total of common units repurchased under a buyback program (in units)	1,408,121
Common units acquired in connection with buyback program	$ 35		$ 35	$ 14
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)			4,255,564
2019 Buyback Program [Member]
Buyback Program:
Amount authorized under 2019 Buyback Program	2,000		$ 2,000
Remaining available capacity under the 2019 Buyback Program	$ 1,500		$ 1,500
Total of common units repurchased under a buyback program (in units)	1,408,121		1,408,121	709,816
Common units acquired in connection with buyback program	$ 35		$ 35	$ 14
At-the-Market Registration [Member]
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
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)			3,240,990