Investments - Schedule of Unrealized Investment Gains and Losses Reflected as a Separate Component of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions |
Mar. 31, 2026 |
Dec. 31, 2025 |
Mar. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|---|---|
| Investments, Debt and Equity Securities [Abstract] | ||||
| Net unrealized gains (losses) on fixed maturity securities without an allowance for credit losses | $ (3,068) | $ (2,356) | ||
| Net unrealized gains (losses) on fixed maturity securities with an allowance for credit losses | (6) | (9) | ||
| Adjustments to policyholder contract balances | 77 | 66 | ||
| Income taxes, net | 456 | 307 | ||
| Net unrealized investment gains (losses) | (2,541) | (1,992) | ||
| Less: net unrealized investment gains (losses) attributable to noncontrolling interests | (15) | (5) | ||
| Net unrealized investment gains (losses) attributable to Genworth Financial, Inc. | $ (2,526) | $ (1,987) | $ (2,660) | $ (3,156) |