Nature of Operations, Basis of Presentation and Summary of Significant Accounting Policies - Summary of Amortization Basis and Expected Amortization Period by Reportable Segment (Details) |
12 Months Ended |
|---|---|
Dec. 31, 2025 | |
| Life Insurance | |
| Product Information [Line Items] | |
| Traditional contract acquisition cost amortization period | 60 years |
| Group Protection | |
| Product Information [Line Items] | |
| Traditional contract acquisition cost amortization period | 4 years |
| Retirement Plan Services | |
| Product Information [Line Items] | |
| Traditional contract acquisition cost amortization period | 40 years |