Purchase and Sale Program (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Purchase And Sale Program [Abstract] | |||
| Trust Interests redeemed | 3,370,923 | 3,727,301 | 3,778,528 |
| Net realized investment gains | $ 225,826,000 | $ 229,291,000 | $ 185,694,000 |
| Maximum Trust Interests Per Beneficiary | 1,000 | ||
| Amount Of Minimum Purchase Requirement | $ 250 | ||
| Trust Interests issued | 7,705 | 10,859 | 17,194 |