Short-Term Debt (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Short-term Debt [Line Items]
Amount outstanding at period end	$ 802	$ 785
Commercial Paper
Short-term Debt [Line Items]
Borrowing limit	3,550	3,550
Amount outstanding at period end	802	785
Average amount outstanding	449	491
Maximum amount outstanding	$ 802	$ 1,241
Weighted average interest rate, computed on a daily basis	5.54%	5.12%
Weighted average interest rate at period end	5.54%	5.52%
Letter of Credit
Short-term Debt [Line Items]
Amount outstanding at period end	$ 43	$ 44