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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Condensed Financial Information (Parent Company) (Long-term Debt Outstanding) (Details) - Parent Company $ in Millions, ¥ in Billions	Dec. 31, 2024 USD ($)	Mar. 31, 2024	Dec. 31, 2023 USD ($)	Jul. 10, 2023 JPY (¥)	Jul. 08, 2023 JPY (¥)	Mar. 31, 2023	Dec. 31, 2022
Condensed Financial Statements, Captions [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		124.00%				100.00%	5.23%
Long-term Debt [Abstract]
Senior Notes	$ 14,431		$ 14,516
Long-term Debt	15,878		16,101
Senior Notes, Unaffiliated [Member]
Long-term Debt [Abstract]
Senior Notes	14,431		14,516
Senior Notes, Affiliated [Member]
Long-term Debt [Abstract]
Senior Notes	$ 1,447		$ 1,585
Minimum \| Senior Notes, Unaffiliated [Member]
Long-term Debt [Abstract]
Debt Instrument, Interest Rate, Effective Percentage	0.50%
Minimum \| Senior Notes, Affiliated [Member]
Long-term Debt [Abstract]
Debt Instrument, Interest Rate, Effective Percentage	1.59%
Maximum \| Senior Notes, Unaffiliated [Member]
Long-term Debt [Abstract]
Debt Instrument, Interest Rate, Effective Percentage	6.50%
Maximum \| Senior Notes, Affiliated [Member]
Long-term Debt [Abstract]
Debt Instrument, Interest Rate, Effective Percentage	7.45%
SeniorDebtYen37.3BillionJuly2023 \| Senior Notes, Affiliated [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					1.6015%
Long-term Debt [Abstract]
Senior Notes \| ¥					¥ 37.3
SeniorDebtYen37.3BillionJuly2030 \| Senior Notes, Affiliated [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				2.1575%
Long-term Debt [Abstract]
Senior Notes \| ¥				¥ 37.3
Note $80M 5.68% maturity March 2033
Condensed Financial Statements, Captions [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			5.68%