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 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Aug. 31, 2016 |
Aug. 31, 2026 |
Aug. 31, 2017 |
Aug. 31, 2018 |
Aug. 31, 2019 |
Aug. 31, 2020 |
Aug. 31, 2021 |
Aug. 31, 2022 |
Aug. 31, 2023 |
Aug. 31, 2024 |
Aug. 31, 2025 |
Aug. 31, 2026 |
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| C000135926 [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Nomura Tax‑Free California Fund (Institutional Class) – including sales charge | |||||||||||
| Accumulated Value | $ 10,000 | $ 10,080 | $ 10,206.31 | $ 11,049.13 | $ 11,254.39 | $ 12,066.54 | $ 10,828.91 | $ 10,960.69 | $ 12,073.37 | $ 11,591.91 | $ 12,242.72 | |
| C000006417 [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Nomura Tax‑Free California Fund (Class C) – including sales charge | |||||||||||
| Accumulated Value | 10,000 | 9,982.66 | 10,007.68 | 10,734.64 | 10,825.02 | 11,478.51 | 10,210.23 | 10,222.71 | 11,147.61 | 10,598.18 | 11,081.76 | |
| C000006415 [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Nomura Tax‑Free California Fund (Class A) – including sales charge | |||||||||||
| Accumulated Value | 9,550 | 9,606 | 9,702 | 10,477 | 10,645 | 11,384 | 10,191 | 10,279 | 11,305 | 10,828 | 11,407 | |
| Bloomberg Municipal Bond Index [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | |||||||||||
| Accumulated Value | $ 10,000 | $ 10,088 | $ 10,138 | $ 11,022 | $ 11,378 | $ 11,765 | $ 10,749 | $ 10,932 | $ 11,598 | $ 11,607 | $ 12,085 | |