Fiduciary Assets and Liabilities (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
|
| Fiduciary Assets and Liabilities [Line Items] | |||||
| Net uncollected premiums and claims receivable and payable | $ 18,200 | $ 18,200 | $ 15,100 | ||
| Operating Segments | Risk and Insurance Services | |||||
| Fiduciary Assets and Liabilities [Line Items] | |||||
| Interest on fiduciary funds | $ 99 | $ 125 | $ 202 | $ 247 | |