Condensed Financial Information (Parent Company) (Loans to Subsidiaries - Narrative) (Details) - Parent Company - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Notes to Condensed Financial Information of Parent Company (Textuals) [Abstract]
Other Receivables, Net, Current	$ 225	$ 250	$ 60	$ 300	$ 250	$ 150
Debt Instrument, Interest Rate, Stated Percentage			5.23%	124.00%	100.00%
Note $80M 5.34% maturity in March 2028
Notes to Condensed Financial Information of Parent Company (Textuals) [Abstract]
Other Receivables, Net, Current		$ 80
Debt Instrument, Interest Rate, Stated Percentage		5.34%
Note $80M 5.68% maturity March 2033
Notes to Condensed Financial Information of Parent Company (Textuals) [Abstract]
Other Receivables, Net, Current		$ 80
Debt Instrument, Interest Rate, Stated Percentage		5.68%
Note $50M 6.05% maturity March 2038
Notes to Condensed Financial Information of Parent Company (Textuals) [Abstract]
Other Receivables, Net, Current		$ 50
Debt Instrument, Interest Rate, Stated Percentage		6.05%
Interest Income [Member]
Notes to Condensed Financial Information of Parent Company (Textuals) [Abstract]
Interest Income, Other	$ 28	$ 22	$ 2