Insurance Liabilities - Account balances by guaranteed minimum interest rates (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2022
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 101,902	$ 103,226
Account balance percentage	100.00%	100.00%
At Guaranteed Minimum
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 58,748	$ 70,515
Account balance percentage	58.00%	68.00%
1 Basis Point - 50 Basis Points Above
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 8,075	$ 4,816
Account balance percentage	8.00%	5.00%
More than 50 Basis Points Above Minimum Guarantee
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 35,079	$ 27,895
Account balance percentage	34.00%	27.00%
Individual Retirement
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 56,699	$ 56,442
Individual Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	33,231	31,943
Individual Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	6,241	5,991
Individual Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	9,574	10,014
Individual Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	7,167	7,980
Individual Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	450	476
Individual Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	36	38
Individual Retirement | At Guaranteed Minimum
Policyholder Account Balance [Line Items]
Policyholder Account Balance	27,626	33,034
Individual Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	7,044	10,300
Individual Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	4,151	4,300
Individual Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	8,831	9,995
Individual Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	7,122	7,934
Individual Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	446	471
Individual Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	32	34
Individual Retirement | 1 Basis Point - 50 Basis Points Above
Policyholder Account Balance [Line Items]
Policyholder Account Balance	2,463	1,841
Individual Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	2,390	1,775
Individual Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	23	25
Individual Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	11	1
Individual Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	39	40
Individual Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Individual Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Individual Retirement | More than 50 Basis Points Above Minimum Guarantee
Policyholder Account Balance [Line Items]
Policyholder Account Balance	26,610	21,567
Individual Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	23,797	19,868
Individual Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	2,067	1,666
Individual Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	732	18
Individual Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	6	6
Individual Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	4	5
Individual Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	4	4
Group Retirement
Policyholder Account Balance [Line Items]
Policyholder Account Balance	37,914	39,299
Group Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	10,974	10,208
Group Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	6,065	6,727
Group Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	13,274	14,556
Group Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	651	696
Group Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	6,799	6,953
Group Retirement | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	151	159
Group Retirement | At Guaranteed Minimum
Policyholder Account Balance [Line Items]
Policyholder Account Balance	26,792	32,491
Group Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	2,018	3,817
Group Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	4,050	6,310
Group Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	13,123	14,556
Group Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	651	696
Group Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	6,799	6,953
Group Retirement | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	151	159
Group Retirement | 1 Basis Point - 50 Basis Points Above
Policyholder Account Balance [Line Items]
Policyholder Account Balance	4,287	2,127
Group Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	2,574	1,717
Group Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	1,624	410
Group Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	89	0
Group Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Group Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Group Retirement | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Group Retirement | More than 50 Basis Points Above Minimum Guarantee
Policyholder Account Balance [Line Items]
Policyholder Account Balance	6,835	4,681
Group Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	6,382	4,674
Group Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	391	7
Group Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	62	0
Group Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Group Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Group Retirement | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Life Insurance
Policyholder Account Balance [Line Items]
Policyholder Account Balance	7,289	7,485
Life Insurance | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Life Insurance | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	481	479
Life Insurance | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	1,965	1,986
Life Insurance | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	1,713	1,770
Life Insurance | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	2,909	3,024
Life Insurance | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	221	226
Life Insurance | At Guaranteed Minimum
Policyholder Account Balance [Line Items]
Policyholder Account Balance	4,330	4,990
Life Insurance | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Life Insurance | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	105
Life Insurance | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	10	240
Life Insurance | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	1,190	1,395
Life Insurance | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	2,909	3,024
Life Insurance | At Guaranteed Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	221	226
Life Insurance | 1 Basis Point - 50 Basis Points Above
Policyholder Account Balance [Line Items]
Policyholder Account Balance	1,325	848
Life Insurance | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Life Insurance | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	131	24
Life Insurance | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	872	638
Life Insurance | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	322	186
Life Insurance | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Life Insurance | 1 Basis Point - 50 Basis Points Above | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Life Insurance | More than 50 Basis Points Above Minimum Guarantee
Policyholder Account Balance [Line Items]
Policyholder Account Balance	1,634	1,647
Life Insurance | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range Less Than 1%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Life Insurance | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 1% To 2%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	350	350
Life Insurance | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 2% To 3%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	1,083	1,108
Life Insurance | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 3% To 4%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	201	189
Life Insurance | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 4% To 5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Life Insurance | More than 50 Basis Points Above Minimum Guarantee | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 5% To 5.5%
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 0	$ 0