Accumulation Units - Schedule of changes in the number of accumulation units outstanding (Details) - shares shares in Millions |
6 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2025 |
Dec. 31, 2024 |
|
| Outstanding: | ||
| Beginning of period (in shares) | 47.8 | 48.0 |
| Credited for premiums (in shares) | 3.1 | 6.3 |
| Credited for purchase of liquidity units by TIAA (in shares) | 0.0 | 0.6 |
| Annuity, other periodic payments, withdrawals and death benefits (in shares) | (3.6) | (7.1) |
| End of period (in shares) | 47.3 | 47.8 |