Investments (Net Unrealized Gains Losses on Investments) (Details) - USD ($) $ in Millions |
Jun. 30, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Gain (Loss) on Securities [Line Items] | ||
| Net unrealized gains (losses) on investments | $ (28,156) | $ (27,281) |
| Fixed maturities | Available-for-sale | With an allowance | ||
| Gain (Loss) on Securities [Line Items] | ||
| Net unrealized gains (losses) on investments | 3 | 6 |
| Fixed maturities | Available-for-sale | Without an allowance | ||
| Gain (Loss) on Securities [Line Items] | ||
| Net unrealized gains (losses) on investments | (27,550) | (29,109) |
| Derivatives designated as cash flow hedges | ||
| Gain (Loss) on Securities [Line Items] | ||
| Net unrealized gains (losses) on investments | (597) | 1,780 |
| Derivatives designated as fair value hedges | ||
| Gain (Loss) on Securities [Line Items] | ||
| Net unrealized gains (losses) on investments | (168) | (64) |
| Other investments | ||
| Gain (Loss) on Securities [Line Items] | ||
| Net unrealized gains (losses) on investments | $ 156 | $ 106 |