Long-Duration Insurance Contracts - Discount Rates for LFPB (Details)	Mar. 31, 2023	Mar. 31, 2022
Whole Life | Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	1.70%	1.70%
Current discount rate	4.70%	3.20%
Whole Life | Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	4.90%	5.00%
Current discount rate	5.00%	3.70%
Term Life | Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	4.10%	4.10%
Current discount rate	4.90%	3.60%
Term Life | Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	4.30%	4.40%
Current discount rate	5.00%	3.60%
Experience Life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	6.10%	6.10%
Current discount rate	5.00%	3.70%
Limited Pay Whole Life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	3.90%	3.90%
Current discount rate	5.00%	3.70%
Supplemental health | Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	1.70%	1.70%
Current discount rate	5.00%	3.50%
Supplemental health | Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	2.70%	2.70%
Current discount rate	5.20%	4.00%
SPIA (life contingent) | Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	1.70%	1.70%
Current discount rate	4.90%	3.50%
SPIA (life contingent) | Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	4.10%	4.00%
Current discount rate	5.00%	3.50%