Long-Duration Insurance Contracts - Discount Rates for LFPB (Details)	Mar. 31, 2026	Mar. 31, 2025
Whole Life | Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	1.70%	1.70%
Current discount rate	4.80%	4.90%
Whole Life | Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	4.80%	4.80%
Current discount rate	5.90%	5.70%
Term Life | Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	4.10%	4.10%
Current discount rate	5.40%	5.40%
Term Life | Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	4.30%	4.20%
Current discount rate	5.60%	5.40%
Experience life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	6.10%	6.10%
Current discount rate	5.60%	5.50%
Limited-Pay Whole Life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	4.00%	4.00%
Current discount rate	6.00%	5.80%
Supplemental health | Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	1.70%	1.70%
Current discount rate	5.60%	5.50%
Supplemental health | Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	2.80%	2.80%
Current discount rate	5.80%	5.70%
SPIA (life contingent) | Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	1.70%	1.70%
Current discount rate	5.30%	5.30%
SPIA (life contingent) | Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest accretion rate	4.10%	4.10%
Current discount rate	5.40%	5.30%