| Form N-CSR Cover | 6 Months Ended |
| Nov. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | BlackRock California Municipal Series Trust |
| Entity Central Index Key | 0000765199 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Nov. 30, 2024 |
| Shareholder Report | 6 Months Ended | |
| Nov. 30, 2024 USD ($) Holding | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSRS | |
| Amendment Flag | false | |
| Registrant Name | BlackRock California Municipal Series Trust | |
| Entity Central Index Key | 0000765199 | |
| Entity Investment Company Type | N-1A | |
| Document Period End Date | Nov. 30, 2024 | |
| C000011302 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | BlackRock California Municipal Opportunities Fund | |
| Class Name | Institutional Shares | |
| Trading Symbol | MACMX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock California Municipal Opportunities Fund (the “Fund”) for the period of June 1, 2024 to November 30, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports | |
| Additional Information Phone Number | (800) 441‑7762 | |
| Additional Information Website | blackrock.com/fundreports | |
| Expenses [Text Block] | What were the Fund costs for the last six months ? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Institutional Shares $ 0.47 % (a) (a) Annualized. | |
| Expenses Paid, Amount | $ 24 | |
| Expense Ratio, Percent | 0.47% | [1] |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. | |
| Average Annual Return [Table Text Block] | Average annual total returns 6-Month 1 Year 5 Years 10 Years Institutional Shares 3.93 % 6.08 % 1.48 % 2.75 % Bloomberg Municipal Bond Index 4.54 4.93 1.35 2.45 California Customized Reference Benchmark 4.72 5.56 1.28 N/A | |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit blackrock.com | |
| Net Assets | $ 2,417,800,535 | |
| Holdings Count | Holding | 240 | |
| Investment Company Portfolio Turnover | 63% | |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ Number of Portfolio Holdings 240 Portfolio Turnover Rate 63 % | |
| Holdings [Text Block] | What did the Fund invest in? (as of November 30, 2024) Sector allocation Sector (a) Percent of Total (b) County/City/Special District/School District 25.8 % Corporate 22.1 % Utilities 21.0 % Transportation 16.4 % Health 4.6 % State 4.3 % Education 3.2 % Tobacco 2.2 % Housing 0.4 % Credit quality allocation Credit Rating (c) Percent of Total (b) AAA/Aaa 13.1 % AA/Aa 46.0 % A 26.9 % BBB/Baa 1.7 % BB/Ba 0.1 % CCC/Caa 0.1 % N/R (d) 12.1 % (a) For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes. (b) Excludes short-term securities. (c) For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. (d) The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Quality Explanation [Text Block] | The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Ratings Selection [Text Block] | For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. | |
| C000038561 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | BlackRock California Municipal Opportunities Fund | |
| Class Name | Investor A Shares | |
| Trading Symbol | MECMX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock California Municipal Opportunities Fund (the “Fund”) for the period of June 1, 2024 to November 30, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports | |
| Additional Information Phone Number | (800) 441‑7762 | |
| Additional Information Website | blackrock.com/fundreports | |
| Expenses [Text Block] | What were the Fund costs for the last six months ? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Investor A Shares $ 0.71 % (a) (a) Annualized. | |
| Expenses Paid, Amount | $ 36 | |
| Expense Ratio, Percent | 0.71% | [2] |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. | |
| Average Annual Return [Table Text Block] | Average annual total returns 6-Month 1 Year 5 Years 10 Years Investor A Shares 3.81 % 5.83 % 1.25 % 2.50 % Investor A Shares (with sales charge) (0.61 ) 1.33 0.38 2.06 Bloomberg Municipal Bond Index 4.54 4.93 1.35 2.45 California Customized Reference Benchmark 4.72 5.56 1.28 N/A | |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit blackrock.com | |
| Net Assets | $ 2,417,800,535 | |
| Holdings Count | Holding | 240 | |
| Investment Company Portfolio Turnover | 63% | |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ Number of Portfolio Holdings 240 Portfolio Turnover Rate 63 % | |
| Holdings [Text Block] | What did the Fund invest in? (as of November 30, 2024) Sector allocation Sector (a) Percent of Total (b) County/City/Special District/School District 25.8 % Corporate 22.1 % Utilities 21.0 % Transportation 16.4 % Health 4.6 % State 4.3 % Education 3.2 % Tobacco 2.2 % Housing 0.4 % Credit quality allocation Credit Rating (c) Percent of Total (b) AAA/Aaa 13.1 % AA/Aa 46.0 % A 26.9 % BBB/Baa 1.7 % BB/Ba 0.1 % CCC/Caa 0.1 % N/R (d) 12.1 % (a) For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes. (b) Excludes short-term securities. (c) For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. (d) The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Quality Explanation [Text Block] | The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Ratings Selection [Text Block] | For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. | |
| C000011299 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | BlackRock California Municipal Opportunities Fund | |
| Class Name | Investor A1 Shares | |
| Trading Symbol | MDCMX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock California Municipal Opportunities Fund (the “Fund”) for the period of June 1, 2024 to November 30, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports | |
| Additional Information Phone Number | (800) 441‑7762 | |
| Additional Information Website | blackrock.com/fundreports | |
| Expenses [Text Block] | What were the Fund costs for the last six months ? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Investor A1 Shares $ 0.56 % (a) (a) Annualized. | |
| Expenses Paid, Amount | $ 29 | |
| Expense Ratio, Percent | 0.56% | [3] |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. | |
| Average Annual Return [Table Text Block] | Average annual total returns 6-Month 1 Year 5 Years 10 Years Investor A1 Shares 3.88 % 5.99 % 1.41 % 2.66 % Bloomberg Municipal Bond Index 4.54 4.93 1.35 2.45 California Customized Reference Benchmark 4.72 5.56 1.28 N/A | |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit blackrock.com | |
| Net Assets | $ 2,417,800,535 | |
| Holdings Count | Holding | 240 | |
| Investment Company Portfolio Turnover | 63% | |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ Number of Portfolio Holdings 240 Portfolio Turnover Rate 63 % | |
| Holdings [Text Block] | What did the Fund invest in? (as of November 30, 2024) Sector allocation Sector (a) Percent of Total (b) County/City/Special District/School District 25.8 % Corporate 22.1 % Utilities 21.0 % Transportation 16.4 % Health 4.6 % State 4.3 % Education 3.2 % Tobacco 2.2 % Housing 0.4 % Credit quality allocation Credit Rating (c) Percent of Total (b) AAA/Aaa 13.1 % AA/Aa 46.0 % A 26.9 % BBB/Baa 1.7 % BB/Ba 0.1 % CCC/Caa 0.1 % N/R (d) 12.1 % (a) For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes. (b) Excludes short-term securities. (c) For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. (d) The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Quality Explanation [Text Block] | The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Ratings Selection [Text Block] | For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. | |
| C000038562 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | BlackRock California Municipal Opportunities Fund | |
| Class Name | Investor C Shares | |
| Trading Symbol | MFCMX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock California Municipal Opportunities Fund (the “Fund”) for the period of June 1, 2024 to November 30, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports | |
| Additional Information Phone Number | (800) 441‑7762 | |
| Additional Information Website | blackrock.com/fundreports | |
| Expenses [Text Block] | What were the Fund costs for the last six months ? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Investor C Shares $ 1.47 % (a) (a) Annualized. | |
| Expenses Paid, Amount | $ 75 | |
| Expense Ratio, Percent | 1.47% | [4] |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. | |
| Average Annual Return [Table Text Block] | Average annual total returns 6-Month 1 Year 5 Years 10 Years Investor C Shares 3.41 % 5.03 % 0.48 % 1.89 % Investor C Shares (with sales charge) 2.41 4.03 0.48 1.89 Bloomberg Municipal Bond Index 4.54 4.93 1.35 2.45 California Customized Reference Benchmark 4.72 5.56 1.28 N/A | |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit blackrock.com | |
| Net Assets | $ 2,417,800,535 | |
| Holdings Count | Holding | 240 | |
| Investment Company Portfolio Turnover | 63% | |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ Number of Portfolio Holdings 240 Portfolio Turnover Rate 63 % | |
| Holdings [Text Block] | What did the Fund invest in? (as of November 30, 2024) Sector allocation Sector (a) Percent of Total (b) County/City/Special District/School District 25.8 % Corporate 22.1 % Utilities 21.0 % Transportation 16.4 % Health 4.6 % State 4.3 % Education 3.2 % Tobacco 2.2 % Housing 0.4 % Credit quality allocation Credit Rating (c) Percent of Total (b) AAA/Aaa 13.1 % AA/Aa 46.0 % A 26.9 % BBB/Baa 1.7 % BB/Ba 0.1 % CCC/Caa 0.1 % N/R (d) 12.1 % (a) For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes. (b) Excludes short-term securities. (c) For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. (d) The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Quality Explanation [Text Block] | The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Ratings Selection [Text Block] | For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. | |
| C000199773 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | BlackRock California Municipal Opportunities Fund | |
| Class Name | Class K Shares | |
| Trading Symbol | MKCMX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about BlackRock California Municipal Opportunities Fund (the “Fund”) for the period of June 1, 2024 to November 30, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at blackrock.com/fundreports | |
| Additional Information Phone Number | (800) 441‑7762 | |
| Additional Information Website | blackrock.com/fundreports | |
| Expenses [Text Block] | What were the Fund costs for the last six months ? (based on a hypothetical $10,000 investment) Class name Costs of a $10,000 Costs paid as a percentage of a Class K Shares $ 0.42 % (a) (a) Annualized. | |
| Expenses Paid, Amount | $ 21 | |
| Expense Ratio, Percent | 0.42% | [5] |
| Performance Past Does Not Indicate Future [Text] | Past performance is not an indication of future results. | |
| Average Annual Return [Table Text Block] | Average annual total returns 6-Month 1 Year 5 Years 10 Years Class K Shares 4.04 % 6.13 % 1.55 % 2.79 % Bloomberg Municipal Bond Index 4.54 4.93 1.35 2.45 California Customized Reference Benchmark 4.72 5.56 1.28 N/A | |
| Performance Inception Date | Jan. 25, 2018 | |
| No Deduction of Taxes [Text Block] | Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption or sale of fund shares. | |
| Updated Performance Information Location [Text Block] | Visit blackrock.com | |
| Net Assets | $ 2,417,800,535 | |
| Holdings Count | Holding | 240 | |
| Investment Company Portfolio Turnover | 63% | |
| Additional Fund Statistics [Text Block] | Key Fund statistics Net Assets $ Number of Portfolio Holdings 240 Portfolio Turnover Rate 63 % | |
| Holdings [Text Block] | What did the Fund invest in? (as of November 30, 2024) Sector allocation Sector (a) Percent of Total (b) County/City/Special District/School District 25.8 % Corporate 22.1 % Utilities 21.0 % Transportation 16.4 % Health 4.6 % State 4.3 % Education 3.2 % Tobacco 2.2 % Housing 0.4 % Credit quality allocation Credit Rating (c) Percent of Total (b) AAA/Aaa 13.1 % AA/Aa 46.0 % A 26.9 % BBB/Baa 1.7 % BB/Ba 0.1 % CCC/Caa 0.1 % N/R (d) 12.1 % (a) For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes. (b) Excludes short-term securities. (c) For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. (d) The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Quality Explanation [Text Block] | The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments. | |
| Credit Ratings Selection [Text Block] | For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change. | |
| [1]Annualized.[2]Annualized.[3]Annualized.[4]Annualized.[5]Annualized. | ||
| Shareholder Report, Line Graph (Details) | 6 Months Ended | 12 Months Ended | 60 Months Ended | 120 Months Ended |
| Nov. 30, 2024 | Nov. 30, 2024 | Nov. 30, 2024 | Nov. 30, 2024 | |
| C000011302 [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Institutional Shares | |||
| Average Annual Return, Percent | 3.93% | 6.08% | 1.48% | 2.75% |
| C000038561 [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Investor A Shares (with sales charge) | |||
| Average Annual Return, Percent | (0.61%) | 1.33% | 0.38% | 2.06% |
| C000038561 [Member] | Without Sales Load [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Investor A Shares | |||
| Average Annual Return, Percent | 3.81% | 5.83% | 1.25% | 2.50% |
| C000011299 [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Investor A1 Shares | |||
| Average Annual Return, Percent | 3.88% | 5.99% | 1.41% | 2.66% |
| C000038562 [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Investor C Shares (with sales charge) | |||
| Average Annual Return, Percent | 2.41% | 4.03% | 0.48% | 1.89% |
| C000038562 [Member] | Without Sales Load [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Investor C Shares | |||
| Average Annual Return, Percent | 3.41% | 5.03% | 0.48% | 1.89% |
| C000199773 [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Class K Shares | |||
| Average Annual Return, Percent | 4.04% | 6.13% | 1.55% | 2.79% |
| Bloomberg Municipal Bond Index [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | |||
| Average Annual Return, Percent | 4.54% | 4.93% | 1.35% | 2.45% |
| California Customized Reference Benchmark [Member] | ||||
| Account Value [Line Items] | ||||
| Line Graph and Table Measure Name | California Customized Reference Benchmark | |||
| Average Annual Return, Percent | 4.72% | 5.56% | 1.28% |
| Shareholder Report, Holdings (Details) | Nov. 30, 2024 | |
| C000011302 [Member] | N R [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.10% | [1],[2],[3] |
| C000011302 [Member] | Standard & Poor's, AAA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 13.10% | [1],[2] |
| C000011302 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 46% | [1],[2] |
| C000011302 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 26.90% | [1],[2] |
| C000011302 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | [1],[2] |
| C000011302 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [1],[2] |
| C000011302 [Member] | Standard & Poor's, CCC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [1],[2] |
| C000011302 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.60% | [1],[4] |
| C000011302 [Member] | Transportation Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 16.40% | [1],[4] |
| C000011302 [Member] | Utilities Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 21% | [1],[4] |
| C000011302 [Member] | County City Special District School District [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 25.80% | [1],[4] |
| C000011302 [Member] | Corporate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 22.10% | [1],[4] |
| C000011302 [Member] | State [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.30% | [1],[4] |
| C000011302 [Member] | Education [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.20% | [1],[4] |
| C000011302 [Member] | Tobacco [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.20% | [1],[4] |
| C000011302 [Member] | Housing [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.40% | [1],[4] |
| C000038561 [Member] | N R [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.10% | [5],[6],[7] |
| C000038561 [Member] | Standard & Poor's, AAA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 13.10% | [5],[6] |
| C000038561 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 46% | [5],[6] |
| C000038561 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 26.90% | [5],[6] |
| C000038561 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | [5],[6] |
| C000038561 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [5],[6] |
| C000038561 [Member] | Standard & Poor's, CCC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [5],[6] |
| C000038561 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.60% | [5],[8] |
| C000038561 [Member] | Transportation Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 16.40% | [5],[8] |
| C000038561 [Member] | Utilities Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 21% | [5],[8] |
| C000038561 [Member] | County City Special District School District [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 25.80% | [5],[8] |
| C000038561 [Member] | Corporate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 22.10% | [5],[8] |
| C000038561 [Member] | State [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.30% | [5],[8] |
| C000038561 [Member] | Education [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.20% | [5],[8] |
| C000038561 [Member] | Tobacco [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.20% | [5],[8] |
| C000038561 [Member] | Housing [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.40% | [5],[8] |
| C000011299 [Member] | N R [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.10% | [9],[10],[11] |
| C000011299 [Member] | Standard & Poor's, AAA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 13.10% | [9],[10] |
| C000011299 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 46% | [9],[10] |
| C000011299 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 26.90% | [9],[10] |
| C000011299 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | [9],[10] |
| C000011299 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [9],[10] |
| C000011299 [Member] | Standard & Poor's, CCC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [9],[10] |
| C000011299 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.60% | [9],[12] |
| C000011299 [Member] | Transportation Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 16.40% | [9],[12] |
| C000011299 [Member] | Utilities Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 21% | [9],[12] |
| C000011299 [Member] | County City Special District School District [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 25.80% | [9],[12] |
| C000011299 [Member] | Corporate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 22.10% | [9],[12] |
| C000011299 [Member] | State [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.30% | [9],[12] |
| C000011299 [Member] | Education [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.20% | [9],[12] |
| C000011299 [Member] | Tobacco [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.20% | [9],[12] |
| C000011299 [Member] | Housing [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.40% | [9],[12] |
| C000038562 [Member] | N R [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.10% | [13],[14],[15] |
| C000038562 [Member] | Standard & Poor's, AAA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 13.10% | [13],[14] |
| C000038562 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 46% | [13],[14] |
| C000038562 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 26.90% | [13],[14] |
| C000038562 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | [13],[14] |
| C000038562 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [13],[14] |
| C000038562 [Member] | Standard & Poor's, CCC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [13],[14] |
| C000038562 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.60% | [13],[16] |
| C000038562 [Member] | Transportation Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 16.40% | [13],[16] |
| C000038562 [Member] | Utilities Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 21% | [13],[16] |
| C000038562 [Member] | County City Special District School District [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 25.80% | [13],[16] |
| C000038562 [Member] | Corporate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 22.10% | [13],[16] |
| C000038562 [Member] | State [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.30% | [13],[16] |
| C000038562 [Member] | Education [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.20% | [13],[16] |
| C000038562 [Member] | Tobacco [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.20% | [13],[16] |
| C000038562 [Member] | Housing [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.40% | [13],[16] |
| C000199773 [Member] | N R [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.10% | [17],[18],[19] |
| C000199773 [Member] | Standard & Poor's, AAA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 13.10% | [17],[18] |
| C000199773 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 46% | [17],[18] |
| C000199773 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 26.90% | [17],[18] |
| C000199773 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | [17],[18] |
| C000199773 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [17],[18] |
| C000199773 [Member] | Standard & Poor's, CCC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [17],[18] |
| C000199773 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.60% | [17],[20] |
| C000199773 [Member] | Transportation Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 16.40% | [17],[20] |
| C000199773 [Member] | Utilities Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 21% | [17],[20] |
| C000199773 [Member] | County City Special District School District [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 25.80% | [17],[20] |
| C000199773 [Member] | Corporate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 22.10% | [17],[20] |
| C000199773 [Member] | State [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.30% | [17],[20] |
| C000199773 [Member] | Education [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.20% | [17],[20] |
| C000199773 [Member] | Tobacco [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.20% | [17],[20] |
| C000199773 [Member] | Housing [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.40% | [17],[20] |
| [1]Excludes short-term securities.[2]For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change.[3]The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments.[4]For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes.[5]Excludes short-term securities.[6]For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change.[7]The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments.[8]For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes.[9]Excludes short-term securities.[10]For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change.[11]The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments.[12]For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes.[13]Excludes short-term securities.[14]For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change.[15]The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments.[16]For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes.[17]Excludes short-term securities.[18]For purposes of this report, credit quality ratings shown above reflect the highest rating assigned by either S&P Global Ratings or Moody’s Investors Service, Inc. if ratings differ. These rating agencies are independent, nationally recognized statistical rating organizations and are widely used. Investment grade ratings are credit ratings of BBB/Baa or higher. Below investment grade ratings are credit ratings of BB/Ba or lower. Investments designated N/R are not rated by either rating agency. Unrated investments do not necessarily indicate low credit quality. Credit quality ratings are subject to change.[19]The investment adviser evaluates the credit quality of unrated investments based upon certain factors including, but not limited to, credit ratings for similar investments and financial analysis of sectors and individual investments. Using this approach, the investment adviser has deemed certain of these unrated securities as investment grade quality. As of November 30, 2024, the market value of unrated securities deemed by the investment adviser to be investment grade represents less than 1.0% of total investments.[20]For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes. | ||
