Condensed Parent Company Financial Statements (Condensed Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Other	$ 223	$ 240
Total current assets	1,250	1,069
Investments:
Other	201	179
Total investments	559	517
Other assets	2,107	1,980
Total assets	20,163	18,553	$ 17,710
Current liabilities:
Commercial paper	642	515
Other	351	284
Total current liabilities	2,363	2,054
Other liabilities	518	388
Common Equity:
Retained earnings	3,509	3,250
Shares in deferred compensation trust	(13)	(12)
Total common equity	6,276	5,990
Total liabilities and equity	20,163	18,553
Parent Company [Member]
Current assets:
Notes receivable from affiliated companies	65	16
Other	1	5
Total current assets	66	21
Investments:
Investments in consolidated subsidiaries	7,801	7,061
Other	2	2
Total investments	7,803	7,063
Other assets	97	96
Total assets	7,966	7,180
Current liabilities:
Commercial paper	352	279
Notes payable to affiliated companies	1,318	900
Other	10	4
Total current liabilities	1,680	1,183
Other liabilities	1	2
Common Equity:
Common stock and additional paid-in capital	2,780	2,752
Retained earnings	3,518	3,255
Shares in deferred compensation trust	(13)	(12)
Total common equity	6,285	5,995
Total liabilities and equity	$ 7,966	$ 7,180