Long-Duration Insurance Contracts - Actual and Expected Experience of Mortality Rate and Lapse Rate (Details)	Jun. 30, 2024	Jun. 30, 2023
Whole Life Insurance
Liability for Future Policy Benefit, by Product Segment [Line Items]
Mortality, actual experience	0.70%	0.70%
Mortality, expected experience	0.70%	0.70%
Lapse rate, actual experience	2.90%	3.40%
Lapse rate, expected experience	4.40%	4.70%
Term Life Insurance | Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Mortality, actual experience	0.10%	0.10%
Mortality, expected experience	0.10%	0.10%
Lapse rate, actual experience	3.70%	3.60%
Lapse rate, expected experience	5.40%	5.60%
Term Life Insurance | Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Mortality, actual experience	0.30%	0.40%
Mortality, expected experience	0.80%	1.20%
Lapse rate, actual experience	28.60%	5.60%
Lapse rate, expected experience	12.80%	25.90%
Experience Life Insurance
Liability for Future Policy Benefit, by Product Segment [Line Items]
Mortality, actual experience	1.90%	1.70%
Mortality, expected experience	1.70%	1.60%
Lapse rate, actual experience	3.00%	3.10%
Lapse rate, expected experience	3.00%	3.10%
Limited Pay Whole Life Insurance
Liability for Future Policy Benefit, by Product Segment [Line Items]
Mortality, actual experience	0.20%	0.10%
Mortality, expected experience	0.30%	0.20%
Lapse rate, actual experience	3.50%	3.60%
Lapse rate, expected experience	4.70%	5.20%