Short-Term and Long-Term Debt - Credit Facilities and Letters of Credit (Details)	Dec. 31, 2024 USD ($)
Line of Credit Facility [Line Items]
Maximum Available	$ 3,792,000,000
LOCs Issued	1,972,000,000
Five-year revolving credit facility
Line of Credit Facility [Line Items]
Maximum Available	2,000,000,000
LOCs Issued	250,000,000
LOC facility, due August 2031
Line of Credit Facility [Line Items]
Maximum Available	965,000,000
LOCs Issued	895,000,000
LOC facility, due October 2031
Line of Credit Facility [Line Items]
Maximum Available	827,000,000
LOCs Issued	$ 827,000,000