Shareholder Report, Line Graph (Details) - USD ($) |
12 Months Ended | 24 Months Ended | 36 Months Ended | 48 Months Ended | 60 Months Ended | 72 Months Ended | 84 Months Ended | 96 Months Ended | 108 Months Ended | 120 Months Ended | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jul. 31, 2016 |
Jul. 31, 2026 |
Jul. 31, 2017 |
Jul. 31, 2018 |
Jul. 31, 2019 |
Jul. 31, 2020 |
Jul. 31, 2021 |
Jul. 31, 2022 |
Jul. 31, 2023 |
Jul. 31, 2024 |
Jul. 31, 2025 |
Jul. 31, 2026 |
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| C000035521 | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Changing Parameters Fund | |||||||||||
| Accumulated Value | $ 10,000 | $ 10,561 | $ 10,628 | $ 11,088 | $ 12,043 | $ 13,328 | $ 13,108 | $ 13,677 | $ 14,663 | $ 15,452 | $ 16,013 | |
| Bloomberg U.S. Aggregate Bond Index | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | |||||||||||
| Accumulated Value | $ 10,000 | $ 9,949 | $ 9,869 | $ 10,666 | $ 11,746 | $ 11,664 | $ 10,600 | $ 10,243 | $ 10,766 | $ 11,130 | $ 11,431 | |