| Form N-CSR Cover | 12 Months Ended |
| Aug. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | Schwab Investments |
| Entity Central Index Key | 0000869365 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Aug. 31, 2024 |
| Shareholder Report | 12 Months Ended | |
| Aug. 31, 2024 USD ($) Holding | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSR | |
| Amendment Flag | false | |
| Registrant Name | Schwab Investments | |
| Entity Central Index Key | 0000869365 | |
| Entity Investment Company Type | N-1A | |
| Document Period End Date | Aug. 31, 2024 | |
| Schwab Treasury Inflation Protected Securities Index Fund [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Schwab Treasury Inflation Protected Securities Index Fund | |
| Class Name | Schwab Treasury Inflation Protected Securities Index Fund | |
| Trading Symbol | SWRSX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the fund for the period of September 1, 2023, to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at www.schwabassetmanagement.com/prospectus . this information by calling 1-866-414-6349 or by sending an email request to orders mysummaryprospectus.com . | |
| Additional Information Phone Number | 1-866-414-6349 | |
| Additional Information Email | orders@mysummaryprospectus.com | |
| Additional Information Website | www.schwabassetmanagement.com/prospectus | |
| Expenses [Text Block] | FUND COSTS FOR THE LAST year ENDED August 31, 2024 (BASED ON A HYPOTHETICAL $10,000 INVESTMENT) COSTS OF A $10,000 INVESTMENT COSTS PAID AS A PERCENTAGE OF A $10,000 INVESTMENT Schwab Treasury Inflation Protected Securities Index Fund $5 0.05% | |
| Expenses Paid, Amount | $ 5 | |
| Expense Ratio, Percent | 0.05% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT’S DISCUSSION OF FUND PERFORMANCE For the 12-month reporting period ended August 31, 2024, the fund returned 6.07%. The Bloomberg US Aggregate Bond Index, which serves at the fund’s regulatory index and provides a broad measure of market performance, returned 7.30%. The fund generally invests in securities that are included in the Bloomberg US Treasury Inflation-Linked Bond Index (Series-L) SM which returned 6.17%. The fund does not seek to track the regulatory index. Differences between the return of the fund and the return of the Bloomberg US Treasury Inflation-Linked Bond Index (Series-L) SM may be attributable to, among other things, the operational and transactional costs incurred by the fund and not the index. ■ Of the fund’s return, approximately two thirds came from income, with the remainder coming from price appreciation Portfolio holdings may have changed since | |
| Performance Past Does Not Indicate Future [Text] | The performance data quoted represents past performance. Past performance does not guarantee future results. | |
| Line Graph [Table Text Block] | Performance of Hypothetical $10,000 Investment (August 31, 2014 - August 31, 2024) 1 All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. Index ownership — Bloomberg ® and Bloomberg US Treasury Inflation-Linked Bond Index (Series-L) SM are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL), the administrator of the indices (collectively, “Bloomberg”). Bloomberg is not affiliated with Charles Schwab Investment Management, Inc., dba Schwab Asset Management, and Bloomberg does not approve, endorse, review, or recommend Schwab Treasury Inflation Protected Securities Index Fund. Bloomberg does not guarantee the timeliness, accurateness, or completeness of any data or information relating to Schwab Treasury Inflation Protected Securities Index Fund. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Average Annual Return [Table Text Block] | Average Annual Returns 1 Fund and Inception Date 1 Year 5 Years 10 Years Fund: Schwab Treasury Inflation Protected Securities Index Fund (03/31/2006) 6.07% 1.97% 2.03% Bloomberg US Aggregate Bond Index 2 7.30% -0.04% 1.64% Bloomberg US Treasury Inflation-Linked Bond Index (Series-L) SM 6.17% 2.04% 2.13% All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. Index ownership — Bloomberg ® and Bloomberg US Treasury Inflation-Linked Bond Index (Series-L) SM are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL), the administrator of the indices (collectively, “Bloomberg”). Bloomberg is not affiliated with Charles Schwab Investment Management, Inc., dba Schwab Asset Management, and Bloomberg does not approve, endorse, review, or recommend Schwab Treasury Inflation Protected Securities Index Fund. Bloomberg does not guarantee the timeliness, accurateness, or completeness of any data or information relating to Schwab Treasury Inflation Protected Securities Index Fund. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. 2 In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg US Treasury Inflation-Linked Bond Index (Series-L) SM to the Bloomberg US Aggregate Bond Index. The Bloomberg US Aggregate Bond Index provides a broad measure of market performance. The fund generally invests in securities that are included in the Bloomberg US Treasury Inflati on-Li SM . The fund does | |
| Performance Inception Date | Mar. 31, 2006 | |
| No Deduction of Taxes [Text Block] | Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | To obtain performance information current to the most recent month end, please visit www.schwabassetmanagement.com/prospectus. | |
| Net Assets | $ 2,479,000,000 | |
| Holdings Count | Holding | 49 | |
| Advisory Fees Paid, Amount | $ 1,272,843 | |
| Investment Company, Portfolio Turnover | 31% | |
| Additional Fund Statistics [Text Block] | Statistics Net Assets (millions) $2,479 Number of Holdings 49 Portfolio Turnover Rate 31% Advisory Fees Paid by the Fund $1,272,843 30-Day SEC Yield 2.25% 12-Month Distribution Yield 3.74% Weighted Average Maturity 7.4 Yrs Weighted Average Duration 6.8 Yrs Business Interest Deduction (163j) 99.8 0 | |
| Holdings [Text Block] | Portfolio Composition By Security Type % of Investments Portfolio Composition By Credit Quality % of Investments 2 Portfolio holdings may have changed since the report date. The fund’s yields, including the SEC Yield, are adjusted monthly based on changes in the rate of inflation and these changes can cause the yield to vary substantially from month to month. Exceptionally high yield is attributable to the rise in inflation rate and might not be repeated. Exceptionally low or negative yield is attributable to the fall in inflation rate and might not be repeated. Fixed-income securities are subject to increased loss of principal during periods of rising interest rates. An investment in the fund(s) is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. Treasury Inflation Protected Securities (TIPS) are inflation-linked securities issued by the U.S. Government whose principal value is adjusted periodically in accordance with the rise and fall in the inflation rate. Thus, the dividend amount payable is also impacted by variations in the inflation rate, as it is based upon the principal value of the bond. It may fluctuate up or down. Repayment at maturity is guaranteed by the U.S. Government and may be adjusted for inflation to become the greater of the original face amount at issuance or that face amount plus an adjustment for inflation. Treasury Inflation-Protected Securities are guaranteed by the U.S. Government, but inflation-protected bond funds do not provide such a guarantee. 1 Includes the fund’s position(s) in money market mutual funds registered under the Investment Company Act of 1940, as amended. 2 Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Credit Quality Explanation [Text Block] | Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Schwab U.S. Aggregate Bond Index Fund [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Schwab U.S. Aggregate Bond Index Fund | |
| Class Name | Schwab U.S. Aggregate Bond Index Fund | |
| Trading Symbol | SWAGX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the fund for the period of September 1, 2023, to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at www.schwabassetmanagement.com/prospectus . You can also request this information by calling 1-866-414-6349 or by sending an email request to orders mysummaryprospectus.com . | |
| Additional Information Phone Number | 1-866-414-6349 | |
| Additional Information Email | orders@mysummaryprospectus.com | |
| Additional Information Website | www.schwabassetmanagement.com/prospectus | |
| Expenses [Text Block] | FUND COSTS FOR THE LAST year ENDED August 31, 2024 (BASED ON A HYPOTHETICAL $10,000 INVESTMENT) COSTS OF A $10,000 INVESTMENT COSTS PAID AS A PERCENTAGE OF A $10,000 INVESTMENT Schwab U.S. Aggregate Bond Index Fund $4 0.04% | |
| Expenses Paid, Amount | $ 4 | |
| Expense Ratio, Percent | 0.04% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT’S DISCUSSION OF FUND PERFORMANCE For the 12-month reporting period ended August 31, 2024, the fund returned 7.23%. The Bloomberg US Aggregate Bond Index returned 7.30%. Differences between the return of the fund and the return of the index may be attributable to, among other things, the operational and transactional costs incurred by the fund and not the index. ■ Of the fund’s return, over half came from income, with the remainder coming from price appreciation ■ The fund held positions in TBAs, or “to-be-announced” securities, which are mortgage-backed bonds that settle on a forward date. The fund’s average month-end position in these securities was 1.8%, with a minimum exposure of 1.1% and maximum exposure of 2.4% over the period. Portfolio holdings may have ch | |
| Performance Past Does Not Indicate Future [Text] | The performance data quoted represents past performance. Past performance does not guarantee future results. | |
| Line Graph [Table Text Block] | Performance of Hypothetical $10,000 Investment (February 23, 2017 - August 31, 2024) 1 All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. Index ownership — Bloomberg ® and Bloomberg US Aggregate Bond Index are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL), the administrator of the indices (collectively, “Bloomberg”). Bloomberg is not affiliated with Charles Schwab Investment Management, Inc., dba Schwab Asset Management, and Bloomberg does not approve, endorse, review, or recommend Schwab U.S. Aggregate Bond Index Fund. Bloomberg does not guarantee the timeliness, accurateness, or completeness of any data or information relating to Schwab U.S. Aggregate Bond Index Fund. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Average Annual Return [Table Text Block] | Average Annual Returns 1 Fund and Inception Date 1 Year 5 Years Since Inception Fund: Schwab U.S. Aggregate Bond Index Fund (02/23/2017) 7.23% -0.15% 1.42% Bloomberg US Aggregate Bond Index 7.30% -0.04% 1.54% All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. Index ownership — Bloomberg ® and Bloomberg US Aggregate Bond Index are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL), the administrator of the indices (collectively, “Bloomberg”). Bloomberg is not affiliated with Charles Schwab Investment Management, Inc., dba Schwab Asset Management, and Bloomberg does not approve, endorse, review, or recommend Schwab U.S. Aggregate Bond Index Fund. Bloomberg does not guarantee the timeliness, accurateness, or completeness of any data or information relating to Schwab U.S. Aggregate Bond Index Fund. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Performance Inception Date | Feb. 23, 2017 | |
| No Deduction of Taxes [Text Block] | Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | To obtain performance information current to the most recent month end, please visit www.schwabassetmanagement.com/prospectus | |
| Net Assets | $ 5,144,000,000 | |
| Holdings Count | Holding | 10,046 | |
| Advisory Fees Paid, Amount | $ 1,834,412 | |
| Investment Company, Portfolio Turnover | 60% | |
| Additional Fund Statistics [Text Block] | Statistics Net Assets (millio ns) $5,144 Number of Holdings 10,046 Portfolio Turnover Rate 60% Advisory Fees Paid by the Fund $1,834,412 30-Day SEC Yield 4.10% 12-Month Distribution Yield 3.62% Weighted Average Maturity 8.3 Yrs Weighted Average Duration 6.0 Yrs Business Interest Deduction (163j) 98.2 7 | |
| Holdings [Text Block] | Portfolio Composition By Security Type % of Investmen ts Portfolio Composition By Credit Quality % of Investments 3 Portfolio holdings may have changed since the report date. Fixed-income securities are subject to increased loss of principal during periods of rising interest rates. An investment in the fund(s) is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. 1 The fund may seek to obtain exposure to U.S. agency mortgage pass-through securities, in part or in full, through the use of “to-be-announced” or “TBA” transactions, which are standardized contracts for future delivery of mortgage pass-through securities in which the exact mortgage pools to be delivered are not specified until a few days prior to settlement. These transactions represented approximately 1.1% of net assets on August 31, 2024. 2 Includes the fund’s position(s) in money market mutual funds registered under the Investment Company Act of 1940, as amended. 3 Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. 4 Less than 0.05%. | |
| Credit Quality Explanation [Text Block] | Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Schwab Short-Term Bond Index Fund [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Schwab Short-Term Bond Index Fund | |
| Class Name | Schwab Short-Term Bond Index Fund | |
| Trading Symbol | SWSBX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the fund for the period of September 1, 2023, to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at www.schwabassetmanagement.com/prospectus . You can also request this information by calling 1-866-414-6349 or by sending an email request to orders mysummaryprospectus.com . | |
| Additional Information Phone Number | 1-866-414-6349 | |
| Additional Information Email | orders@mysummaryprospectus.com | |
| Additional Information Website | www.schwabassetmanagement.com/prospectus | |
| Expenses [Text Block] | FUND COSTS FOR THE LAST year ENDED August 31, 2024 (BASED ON A HYPOTHETICAL $10,000 INVESTMENT) COSTS OF A $10,000 INVESTMENT COSTS PAID AS A PERCENTAGE OF A $10,000 INVESTMENT Schwab Short-Term Bond Index Fund $6 0.06% | |
| Expenses Paid, Amount | $ 6 | |
| Expense Ratio, Percent | 0.06% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT’S DISCUSSION OF FUND PERFORMANCE For the 12-month reporting period ended August 31, 2024, the fund returned 6.56%. The Bloomberg US Aggregate Bond Index, which serves at the fund’s regulatory index and provides a broad measure of market performance, returned 7.30%. The fund generally invests in securities that are included in the Bloomberg US Government/Credit 1-5 Year Index which returned 6.67%. The fund does not seek to track the regulatory index. Differences between the return of the fund and the return of the Bloomberg US Government/Credit 1-5 Year Index may be attributable to, among other things, the operational and transactional costs incurred by the fund and not the index. ■ Of the fund’s return, approximately two thirds came from income, with the remainder coming from price appreciation Portfolio holdings may have c ha | |
| Performance Past Does Not Indicate Future [Text] | The performance data quoted represents past performance. Past performance does not guarantee future results. | |
| Line Graph [Table Text Block] | Performance of Hypothetical $10,000 Investment (February 23, 2017 - August 31, 2024) 1 All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. Index ownership — Bloomberg ® and Bloomberg US Government/Credit 1-5 Year Index are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL), the administrator of the indices (collectively, “Bloomberg”). Bloomberg is not affiliated with Charles Schwab Investment Management, Inc., dba Schwab Asset Management, and Bloomberg does not approve, endorse, review, or recommend Schwab Short-Term Bond Index Fund. Bloomberg does not guarantee the timeliness, accurateness, or completeness of any data or information relating to Schwab Short-Term Bond Index Fund. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Average Annual Return [Table Text Block] | Average Annual Returns 1 Fund and Inception Date 1 Year 5 Years Since Inception Fund: Schwab Short-Term Bond Index Fund (02/23/2017) 6.56% 1.23% 1.68% Bloomberg US Aggregate Bond Index 2 7.30% -0.04% 1.54% Bloomberg US Government/Credit 1-5 Year Index 6.67% 1.32% 1.79% All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. Index ownership — Bloomberg ® and Bloomberg US Government/Credit 1-5 Year Index are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL), the administrator of the indices (collectively, “Bloomberg”). Bloomberg is not affiliated with Charles Schwab Investment Management, Inc., dba Schwab Asset Management, and Bloomberg does not approve, endorse, review, or recommend Schwab Short-Term Bond Index Fund. Bloomberg does not guarantee the timeliness, accurateness, or completeness of any data or information relating to Schwab Short-Term Bond Index Fund. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. 2 In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg US Government/Credit 1-5 Year Index to the Bloomberg US Aggregate Bond Index. The Bloomberg US Aggregate Bond Index provides a broad measure of market performance. The fund generally invests in securities that are included in the Bloomberg US Government/Credit 1-5 Year Index. The fund does not seek to track the regulatory index. | |
| Performance Inception Date | Feb. 23, 2017 | |
| No Deduction of Taxes [Text Block] | Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | T o obtain performance information current to the most recent month end, please visit www.schwabassetmanagement.com/prospectus . | |
| Net Assets | $ 1,490,000,000 | |
| Holdings Count | Holding | 2,462 | |
| Advisory Fees Paid, Amount | $ 885,782 | |
| Investment Company, Portfolio Turnover | 65% | |
| Additional Fund Statistics [Text Block] | Statistics Net Assets (millio ns) $1,490 Number of Holdings 2,462 Portfolio Turnover Rate 65% Advisory Fees Paid by the Fund $885,782 30-Day SEC Yield 4.08% 12-Month Distribution Yield 3.77% Weighted Average Maturity 2.9 Yrs Weighted Average Duration 2.6 Yrs Business Interest Deduction ( 163j 99.82% | |
| Holdings [Text Block] | Portfolio Composition By Security Type % of Investments Portfolio Composition By Credit Quality % of Investments 2 Portfolio holdings may have changed since the report date. Fixed-income securities are subject to increased loss of principal during periods of rising interest rates. An investment in the fund(s) is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. 1 Includes the fund’s position(s) in money market mutual funds registered under the Investment Company Act of 1940, as amended. 2 Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Credit Quality Explanation [Text Block] | Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Schwab Tax-Free Bond Fund [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Schwab Tax-Free Bond Fund | |
| Class Name | Schwab Tax-Free Bond Fund | |
| Trading Symbol | SWNTX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the fund for the period of September 1, 2023, to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at www.schwabassetmanagement.com/prospectus . You can also request this information by calling 1-866-414-6349 or by sending an email request to orders mysummaryprospectus.com . | |
| Additional Information Phone Number | 1-866-414-6349 | |
| Additional Information Email | orders@mysummaryprospectus.com | |
| Additional Information Website | www.schwabassetmanagement.com/prospectus | |
| Expenses [Text Block] | FUND COSTS FOR THE LAST year ENDED August 31, 2024 (BASED ON A HYPOTHETICAL $10,000 INVESTMENT) COSTS OF A $10,000 INVESTMENT COSTS PAID AS A PERCENTAGE OF A $10,000 INVESTMENT Schwab Tax-Free Bond Fund $39 0.38% | |
| Expenses Paid, Amount | $ 39 | |
| Expense Ratio, Percent | 0.38% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT’S DISCUSSION OF FUND PERFORMANCE For the 12-month reporting period ended August 31, 2024, the fund returned 5.64%. The Bloomberg Municipal Bond Index, which serves at the fund’s regulatory index and provides a broad measure of market performance, returned 6.09%. The Bloomberg Municipal 3-15 Year Blend Index which returned 5.14%, is the fund’s additional index, and is more representative of the fund’s investment universe than the regulatory index. ■ The municipal bond market experienced significant increase in new issue supply during the reporting period as: ● Tax-exempt yields fell from their most recent peak in October 2023, leading to more attractive borrowing costs for issuers ● Low municipal-to-U.S. Treasury yield ratios created opportunity for issuers to refund outstanding taxable bonds with tax-exempt bonds and save on net interest costs ■ The fund’s overweight in the 15+ year portion of the yield curve positively contributed to relative performance as yields fell over reporting period ■ The fund’s underweight to AAA and AA rated securities and overweight to A and BBB rated securities contributed to re performance as A and BBB rated securities outperformed over the reporting period Portfolio holdings may have changed since the report date. | |
| Performance Past Does Not Indicate Future [Text] | The performance data quoted represents past performance. Past performance does not guarantee future results. | |
| Line Graph [Table Text Block] | Performance of Hypothetical $10,000 Investment (August 31, 2014 - August 31, 2024) 1,2 All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. 2 Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the total return/yield may have been lower. | |
| Average Annual Return [Table Text Block] | Average Annual Returns 1,2 Fund and Inception Date 1 Year 5 Years 10 Years Fund: Schwab Tax-Free Bond Fund (09/11/1992) 5.64% 0.81% 1.92% Bloomberg Municipal Bond Index 3 6.09% 1.02% 2.43% Bloomberg Municipal 3-15 Year Blend Index 5.14% 1.09% 2.27% All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. 2 Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the total return/yield may have been lower. 3 In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg Municipal 3-15 Year Blend Index to the Bloomberg Municipal Bond Index. The Bloomberg Municipal Bond Index provides a broad measure of market performance. The Bloomberg Municipal 3-15 Year Blend Index is the fund’s additional index and is more representative of the fund’s investment universe than the regulatory index. | |
| Performance Inception Date | Sep. 11, 1992 | |
| No Deduction of Taxes [Text Block] | Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | To obtain performance information current to the most recent month end, please visit www.schwabassetmanagement.com/prospectus . | |
| Net Assets | $ 591,612,000 | |
| Holdings Count | Holding | 378 | |
| Advisory Fees Paid, Amount | $ 1,113,738 | |
| Investment Company, Portfolio Turnover | 127% | |
| Additional Fund Statistics [Text Block] | Statistics Net Assets (thousands) $591,612 Number of Holdings 378 Portfolio Turnover Rate 127% Advisory Fees Paid by the Fund $1,113,738 30-Day SEC Yield 3.34% 30-Day SEC Yield-No Waiver 3.30% 12-Month Distribution Yield 3.34% Weighted Average Maturity 6.8 Yrs Weighted Average Duration 6.2 Yrs Tax Exempt Income Distribut ion 100.00% | |
| Holdings [Text Block] | Portfolio Composition By Security Type % of Investments Portfolio Composition By Credit Quality % of Investments 1 Portfolio holdings may have changed since the report date. Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the 30-Day SEC Yield and 12-Month Distribution Yield may have been lower. The 30-Day SEC Yield-No Waiver is the yield if fund expenses had not been partially absorbed by the investment adviser and its affiliates. Fixed-income securities are subject to increased loss of principal during periods of rising interest rates. An investment in the fund(s) is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. 1 Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Credit Quality Explanation [Text Block] | Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Schwab California Tax-Free Bond Fund | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Schwab California Tax-Free Bond Fund | |
| Class Name | Schwab California Tax-Free Bond Fund | |
| Trading Symbol | SWCAX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the fund for the period of September 1, 2023, to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at www.schwabassetmanagement.com/prospectus . You can also request this information by calling 1-866-414-6349 or by sending an email request to orders mysummaryprospectus.com . | |
| Additional Information Phone Number | 1-866-414-6349 | |
| Additional Information Email | orders@mysummaryprospectus.com | |
| Additional Information Website | www.schwabassetmanagement.com/prospectus | |
| Expenses [Text Block] | FUND COSTS FOR THE LAST year ENDED August 31, 2024 (BASED ON A HYPOTHETICAL $10,000 INVESTMENT) COSTS OF A $10,000 INVESTMENT COSTS PAID AS A PERCENTAGE OF A $10,000 INVESTMENT Schwab California Tax-Free Bond Fund $39 0.38% | |
| Expenses Paid, Amount | $ 39 | |
| Expense Ratio, Percent | 0.38% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT’S DISCUSSION OF FUND PERFORMANCE For the 12-month reporting period ended August 31, 2024, the fund returned 5.55%. The Bloomberg Municipal Bond Index, which serves at the fund’s regulatory index and provides a broad measure of market performance, returned 6.09%. The Bloomberg California Municipal 3-15 Year Blend Index which returned 4.85%, is the fund’s additional index, and is more representative of the fund’s investment universe than the regulatory index. ■ The municipal bond market experienced significant increase in new issue supply during the reporting period as: ● Tax-exempt yields fell from their most recent peak in October 2023, leading to more attractive borrowing costs for issuers ● Low municipal-to-U.S. Treasury yield ratios created opportunity for issuers to refund outstanding taxable bonds with tax-exempt bonds and save on net interest costs ■ The fund’s overweight in the 15+ year portion of the yield curve positively contributed to relative performance as yields fell over the reporting period ■ The fund’s underweight to AAA and AA rated securities and overweight to A and BBB rated securities contributed to relative perfor m Portfolio holdings may have changed since the report date. | |
| Performance Past Does Not Indicate Future [Text] | The performance data quoted represents past performance. Past performance does not guarantee future results. | |
| Line Graph [Table Text Block] | Performance of Hypothetical $10,000 Investment (August 31, 2014 - August 31, 2024) 1,2 All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. 2 Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the total return/yield may have been lower. | |
| Average Annual Return [Table Text Block] | Average Annual Returns 1,2 Fund and Inception Date 1 Year 5 Years 10 Years Fund: Schwab California Tax-Free Bond Fund (02/24/1992) 5.55% 0.70% 1.88% Bloomberg Municipal Bond Index 3 6.09% 1.02% 2.43% Bloomberg California Municipal 3-15 Year Blend Index 4 4.85% 0.95% N/A 5 S&P California AMT-Free Municipal Bond Index 5.30% 0.89% 2.28% All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which would lower performance. Indices are unmanaged and cannot be invested in directly. Performance results less than one year are not annualized. For index definitions, please see www.schwabassetmanagement.com/glossary. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. 2 Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the total return/yield may have been lower. 3 In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg California Municipal 3-15 Year Blend Index to the Bloomberg Municipal Bond Index. The Bloomberg Municipal Bond Index provides a broad measure of market performance. The Bloomberg California Municipal 3-15 Year Blend Index is the fund’s additional index and is more representative of the fund’s investment universe than the regulatory index. 4 The Bloomberg California Municipal 3-15 Year Blend Index was established effective January 1, 2020. Performance shown prior to January 1, 2020 is based on a subset of securities included in the Bloomberg Municipal 3-15 Year Blend Index. 5 Information not available to the fund. | |
| Performance Inception Date | Feb. 24, 1992 | |
| No Deduction of Taxes [Text Block] | Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | To obtain performance information current to the most recent month end, please visit www.schwabassetmanagement.com/prospectus . | |
| Net Assets | $ 439,249,000 | |
| Holdings Count | Holding | 333 | |
| Advisory Fees Paid, Amount | $ 823,846 | |
| Investment Company, Portfolio Turnover | 81% | |
| Additional Fund Statistics [Text Block] | Statistics Net Assets (thousand s) $439,249 Number of Holdings 333 Portfolio Turnover Rate 81% Advisory Fees Paid by the Fund $823,846 30-Day SEC Yield 3.04% 30-Day SEC Yield-No Waiver 3.00% 12-Month Distribution Yield 3.01% Weighted Average Maturity 5.9 Yrs Weighted Average Duration 5.6 Yrs Tax Exempt Income Distribution 100.00% | |
| Holdings [Text Block] | Portfolio Composition By Security Type % of Investments Portfolio Composition By Credit Quality % of Investments 1 Portfolio holdings may have changed since the report date. Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the 30-Day SEC Yield and 12-Month Distribution Yield may have been lower. The 30-Day SEC Yield-No Waiver is the yield if fund expenses had not been partially absorbed by the investment adviser and its affiliates. Fixed-income securities are subject to increased loss of principal during periods of rising interest rates. An investment in the fund(s) is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. 1 Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Credit Quality Explanation [Text Block] | Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Schwab Opportunistic Municipal Bond Fund [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Schwab Opportunistic Municipal Bond Fund | |
| Class Name | Schwab Opportunistic Municipal Bond Fund | |
| Trading Symbol | SWHYX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the fund for the period of September 1, 2023, to August 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the fund at www.schwabassetmanagement.com/prospectus . You can also request this information by calling 1-866-414-6349 or by sending an email request to orders mysummaryprospectus.com . | |
| Additional Information Phone Number | 1-866-414-6349 | |
| Additional Information Email | orders@mysummaryprospectus.com | |
| Additional Information Website | www.schwabassetmanagement.com/prospectus | |
| Expenses [Text Block] | FUND COSTS FOR THE LAST year ENDED August 31, 2024 (BASED ON A HYPOTHETICAL $10,000 INVESTMENT) COSTS OF A $10,000 INVESTMENT COSTS PAID AS A PERCENTAGE OF A $10,000 INVESTMENT Schwab Opportunistic Municipal Bond Fund $52 0.50% | |
| Expenses Paid, Amount | $ 52 | |
| Expense Ratio, Percent | 0.50% | |
| Factors Affecting Performance [Text Block] | MANAGEMENT’S DISCUSSION OF FUND PERFORMANCE For the 12-month reporting period ended August 31, 2024, the fund returned 7.39%. The Bloomberg Municipal Bond Index returned 6.09%. ■ The municipal bond market experienced significant increase in new issue supply during the reporting period as: ● Tax-exempt yields fell from their most recent peak in October 2023, leading to more attractive borrowing costs for issuers ● Low municipal-to-U.S. Treasury yield ratios created opportunity for issuers to refund outstanding taxable bonds with tax-exempt bonds and save on net interest costs ■ The fund’s overweight in the 15+ year portion of the yield curve positively contributed to relative performance as yields fell over the reporting period ■ The fund’s underweight to AAA and AA rated securities and overweight to A and BBB rated securities contributed to relative performance as A and BBB rated securities outperformed over the reporting period Portfolio hold ha an e the | |
| Performance Past Does Not Indicate Future [Text] | The performance data quoted represents past performance. Past performance does not guarantee future results. | |
| Line Graph [Table Text Block] | Performance of Hypothetical $10,000 Investment (August 31, 2014 - August 31, 2024) 1,2,3 All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which performance For index definitions, please see www.schwabassetmanagement.com/glossary. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. 2 Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the total return/yield may have been lower. | |
| Average Annual Return [Table Text Block] | Average Annual Returns 1,2,3 Fund and Inception Date 1 Year 5 Years 10 Years Fund: Schwab Opportunistic Municipal Bond Fund (03/31/2014) 4 7.39% 0.13% 2.94% Bloomberg Municipal Bond Index 6.09% 1.02% 2.43% All total returns on this page assume dividends and distributions were reinvested. Index figures do not include trading and management costs, which performance For index definitions, please see www.schwabassetmanagement.com/glossary. 1 Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. 2 Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the total return/yield may have been lower. 3 Effective August 10, 2020, the Wasmer Schroeder High Yield Municipal Fund (the predecessor fund) was reorganized into the Schwab Opportunistic Municipal Bond Fund. The 4 Inception date is that of the predecessor fund. | |
| Performance Inception Date | Mar. 31, 2014 | [1] |
| No Deduction of Taxes [Text Block] | Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares. | |
| Updated Performance Information Location [Text Block] | To obtain performance information current to the most recent month end, please visit www.schwabassetmanagement.com/prospectus . | |
| Net Assets | $ 67,548,000 | |
| Holdings Count | Holding | 218 | |
| Advisory Fees Paid, Amount | $ 157,086 | |
| Investment Company, Portfolio Turnover | 181% | |
| Additional Fund Statistics [Text Block] | Statistics Net Assets (thousan ds) $67,548 Number of Holdings 218 Portfolio Turnover Rate 181% Advisory Fees Paid by the Fund $157,086 30-Day SEC Yield 3.40% 30-Day SEC Yield-No Waiver 3.30% 12-Month Distribution Yield 4.05% Weighted Average Maturity 9.4 Yrs Weighted Average Duration 8.1 Yrs Tax Exempt Income Distribution 99.77% | |
| Holdings [Text Block] | Portfolio Composition By Security Type % of Investments Portfolio Composition By Credit Quality % of Investments 1 Portfolio holdings may have changed since the report date. Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the 30-Day SEC Yield and 12-Month Distribution Yield may have been lower. The 30-Day SEC Yield-No Waiver is the yield if fund expenses had not been partially absorbed by the investment adviser and its affiliates. Fixed-income securities are subject to increased loss of principal during periods of rising interest rates. An investment in the fund(s) is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. 1 Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| Credit Quality Explanation [Text Block] | Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd. | |
| [1]Inception date is that of the predecessor fund. | ||
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | ||||||||||||
| Aug. 31, 2024 | Aug. 31, 2023 | Aug. 31, 2022 | Aug. 31, 2021 | Aug. 31, 2020 | Aug. 31, 2019 | Aug. 31, 2018 | Aug. 31, 2017 | Feb. 23, 2017 | Aug. 31, 2016 | Aug. 31, 2015 | Aug. 31, 2014 | ||
| Schwab Opportunistic Municipal Bond Fund [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | Schwab Opportunistic Municipal Bond Fund | ||||||||||||
| Account Value | [1],[2],[3] | $ 13,366.25 | $ 12,446.42 | $ 12,186.16 | $ 13,707.62 | $ 13,023.21 | $ 13,278.08 | $ 12,269.39 | $ 11,997.58 | $ 11,736.86 | $ 10,726.05 | $ 10,000 | |
| Schwab California Tax-Free Bond Fund | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | Schwab California Tax-Free Bond Fund | ||||||||||||
| Account Value | [2],[3] | $ 12,045.05 | 11,409.96 | 11,223.45 | 12,195.62 | 11,928.41 | 11,634.37 | 10,853.71 | 10,837.86 | 10,799.45 | 10,222.42 | 10,000 | |
| Schwab Tax-Free Bond Fund [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | Schwab Tax-Free Bond Fund | ||||||||||||
| Account Value | [2],[3] | $ 12,102.4 | 11,453.63 | 11,235.58 | 12,276.81 | 11,916.5 | 11,625.18 | 10,786.65 | 10,809.35 | 10,741.81 | 10,194.77 | 10,000 | |
| Schwab Short-Term Bond Index Fund [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | Schwab Short-Term Bond Index Fund | ||||||||||||
| Account Value | [3] | $ 11,340.75 | 10,640.74 | 10,526.61 | 11,175.56 | 11,155.85 | 10,666.66 | 10,072.79 | 10,124.29 | $ 10,002 | |||
| Schwab U.S. Aggregate Bond Index Fund [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | Schwab U.S. Aggregate Bond Index Fund | ||||||||||||
| Account Value | [3] | $ 11,118.04 | 10,366.16 | 10,506.41 | 11,873.54 | 11,909.57 | 11,201.64 | 10,168.35 | 10,287.56 | 10,022 | |||
| Schwab Treasury Inflation Protected Securities Index Fund [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | Schwab Treasury Inflation Protected Securities Index Fund | ||||||||||||
| Account Value | [3] | $ 12,229.62 | 11,530.11 | 11,969.14 | 12,739.07 | 12,076.77 | 11,092.01 | 10,325.59 | 10,252.73 | 10,216.7 | 9,710.21 | 10,000 | |
| Bloomberg Municipal Bond Index [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | [4],[5] | Bloomberg Municipal Bond Index | |||||||||||
| Account Value | $ 12,708.47 | 11,979.13 | 11,778.36 | 12,891.18 | 12,467.77 | 12,077.01 | 11,108.44 | 11,054.46 | 10,957.66 | 10,252.48 | 10,000 | ||
| Bloomberg US Aggregate Bond Index [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | [6],[7] | Bloomberg US Aggregate Bond Index | |||||||||||
| Account Value | $ 11,765.42 | 10,965.32 | 11,097.74 | 12,542.07 | 12,552.66 | 11,789.47 | 10,700.93 | 10,814.41 | 10,761.41 | 10,155.52 | 10,000 | ||
| Bloomberg California Municipal 3-15 Year Blend Index [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | [8] | Bloomberg California Municipal 3-15 Year Blend Index | |||||||||||
| Account Value | $ 11,468.18 | 10,937.37 | 10,745.42 | 11,557.19 | 11,332.83 | 10,937.48 | 10,162.8 | 10,136.75 | |||||
| S&P California AMT-Free Municipal Bond Index [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | S&P California AMT-Free Municipal Bond Index | ||||||||||||
| Account Value | $ 12,525.8 | 11,895.22 | 11,658.7 | 12,679.74 | 12,404.91 | 11,985.03 | 11,080.47 | 11,018.11 | 10,979.65 | 10,268.9 | 10,000 | ||
| Bloomberg Municipal 3-15 Year Blend Index [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal 3-15 Year Blend Index | ||||||||||||
| Account Value | $ 12,512.86 | 11,901.67 | 11,704.17 | 12,604.34 | 12,269.67 | 11,854.46 | 10,942.85 | 10,956.97 | 10,829.41 | 10,202.47 | 10,000 | ||
| Bloomberg US Government/Credit 1-5 Year Index [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | Bloomberg US Government/Credit 1-5 Year Index | ||||||||||||
| Account Value | $ 11,426.52 | 10,712.01 | 10,586.44 | 11,243.48 | 11,206.89 | 10,701.49 | 10,099.35 | 10,143.23 | $ 10,009.24 | ||||
| Bloomberg US Treasury Inflation Linked Bond Index Series L SM [Member] | |||||||||||||
| Account Value [Line Items] | |||||||||||||
| Line Graph and Table Measure Name | Bloomberg US Treasury Inflation-Linked Bond Index (Series-L)SM | ||||||||||||
| Account Value | $ 12,341.14 | $ 11,623.54 | $ 12,067.18 | $ 12,834.44 | $ 12,158.94 | $ 11,156.26 | $ 10,381.76 | $ 10,296.68 | $ 10,249.45 | $ 9,726.66 | $ 10,000 | ||
| [1]Effective August 10, 2020, the Wasmer Schroeder High Yield Municipal Fund (the predecessor fund) was reorganized into the Schwab Opportunistic Municipal Bond Fund. The performance and financial history prior to August 10, 2020 are that of the predecessor fund.[2]Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the total return/yield may have been lower.[3]Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares.[4]In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg California Municipal 3-15 Year Blend Index to the Bloomberg Municipal Bond Index. The Bloomberg Municipal Bond Index provides a broad measure of market performance. The Bloomberg California Municipal 3-15 Year Blend Index is the fund’s additional index and is more representative of the fund’s investment universe than the regulatory index.[5]In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg Municipal 3-15 Year Blend Index to the Bloomberg Municipal Bond Index. The Bloomberg Municipal Bond Index provides a broad measure of market performance. The Bloomberg Municipal 3-15 Year Blend Index is the fund’s additional index and is more representative of the fund’s investment universe than the regulatory index.[6]In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg US Government/Credit 1-5 Year Index to the Bloomberg US Aggregate Bond Index. The Bloomberg US Aggregate Bond Index provides a broad measure of market performance. The fund generally invests in securities that are included in the Bloomberg US Government/Credit 1-5 Year Index. The fund does not seek to track the regulatory index.[7]In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg US Treasury Inflation-Linked Bond Index (Series-L)SM to the Bloomberg US Aggregate Bond Index. The Bloomberg US Aggregate Bond Index provides a broad measure of market performance. The fund generally invests in securities that are included in the Bloomberg US Treasury Inflation-Linked Bond Index (Series-L)SM. The fund does not seek to track the regulatory index.[8]The Bloomberg California Municipal 3-15 Year Blend Index was established effective January 1, 2020. Performance shown prior to January 1, 2020 is based on a subset of securities included in the Bloomberg Municipal 3-15 Year Blend Index. | |||||||||||||
| Shareholder Report, Average Annual Return (Details) | 12 Months Ended | 60 Months Ended | 90 Months Ended | 120 Months Ended | |
| Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | ||
| Schwab Opportunistic Municipal Bond Fund [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Schwab Opportunistic Municipal Bond Fund | ||||
| Average Annual Return, Percent | [1],[2],[3] | 7.39% | 0.13% | 2.94% | |
| Schwab California Tax-Free Bond Fund | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Schwab California Tax-Free Bond Fund | ||||
| Average Annual Return, Percent | [2],[3] | 5.55% | 0.70% | 1.88% | |
| Schwab Tax-Free Bond Fund [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Schwab Tax-Free Bond Fund | ||||
| Average Annual Return, Percent | [2],[3] | 5.64% | 0.81% | 1.92% | |
| Schwab Short-Term Bond Index Fund [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Schwab Short-Term Bond Index Fund | ||||
| Average Annual Return, Percent | [3] | 6.56% | 1.23% | 1.68% | |
| Schwab U.S. Aggregate Bond Index Fund [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Schwab U.S. Aggregate Bond Index Fund | ||||
| Average Annual Return, Percent | [3] | 7.23% | (0.15%) | 1.42% | |
| Schwab Treasury Inflation Protected Securities Index Fund [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Schwab Treasury Inflation Protected Securities Index Fund | ||||
| Average Annual Return, Percent | [3] | 6.07% | 1.97% | 2.03% | |
| Bloomberg Municipal Bond Index [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | [4],[5] | Bloomberg Municipal Bond Index | |||
| Average Annual Return, Percent | 6.09% | 1.02% | 2.43% | ||
| Bloomberg US Aggregate Bond Index [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | [6],[7] | Bloomberg US Aggregate Bond Index | |||
| Average Annual Return, Percent | 7.30% | (0.04%) | 1.54% | 1.64% | |
| Bloomberg California Municipal 3-15 Year Blend Index [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | [8] | Bloomberg California Municipal 3-15 Year Blend Index | |||
| Average Annual Return, Percent | 4.85% | 0.95% | |||
| S&P California AMT-Free Municipal Bond Index [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | S&P California AMT-Free Municipal Bond Index | ||||
| Average Annual Return, Percent | 5.30% | 0.89% | 2.28% | ||
| Bloomberg Municipal 3-15 Year Blend Index [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg Municipal 3-15 Year Blend Index | ||||
| Average Annual Return, Percent | 5.14% | 1.09% | 2.27% | ||
| Bloomberg US Government/Credit 1-5 Year Index [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg US Government/Credit 1-5 Year Index | ||||
| Average Annual Return, Percent | 6.67% | 1.32% | 1.79% | ||
| Bloomberg US Treasury Inflation-Linked Bond Index (Series-L)SM [Member] | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg US Treasury Inflation-Linked Bond Index (Series-L)SM | ||||
| Average Annual Return, Percent | 6.17% | 2.04% | 2.13% | ||
| [1]Effective August 10, 2020, the Wasmer Schroeder High Yield Municipal Fund (the predecessor fund) was reorganized into the Schwab Opportunistic Municipal Bond Fund. The performance and financial history prior to August 10, 2020 are that of the predecessor fund.[2]Fund expenses may have been partially absorbed by the investment adviser and its affiliates. Without these reductions, the total return/yield may have been lower.[3]Performance does not reflect the deduction of taxes that a shareholder would pay on fund distributions or on the redemption of fund shares.[4]In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg California Municipal 3-15 Year Blend Index to the Bloomberg Municipal Bond Index. The Bloomberg Municipal Bond Index provides a broad measure of market performance. The Bloomberg California Municipal 3-15 Year Blend Index is the fund’s additional index and is more representative of the fund’s investment universe than the regulatory index.[5]In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg Municipal 3-15 Year Blend Index to the Bloomberg Municipal Bond Index. The Bloomberg Municipal Bond Index provides a broad measure of market performance. The Bloomberg Municipal 3-15 Year Blend Index is the fund’s additional index and is more representative of the fund’s investment universe than the regulatory index.[6]In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg US Government/Credit 1-5 Year Index to the Bloomberg US Aggregate Bond Index. The Bloomberg US Aggregate Bond Index provides a broad measure of market performance. The fund generally invests in securities that are included in the Bloomberg US Government/Credit 1-5 Year Index. The fund does not seek to track the regulatory index.[7]In anticipation of new regulatory requirements, the fund’s regulatory index has changed from the Bloomberg US Treasury Inflation-Linked Bond Index (Series-L)SM to the Bloomberg US Aggregate Bond Index. The Bloomberg US Aggregate Bond Index provides a broad measure of market performance. The fund generally invests in securities that are included in the Bloomberg US Treasury Inflation-Linked Bond Index (Series-L)SM. The fund does not seek to track the regulatory index.[8]The Bloomberg California Municipal 3-15 Year Blend Index was established effective January 1, 2020. Performance shown prior to January 1, 2020 is based on a subset of securities included in the Bloomberg Municipal 3-15 Year Blend Index. | |||||
| Shareholder Report, Holdings (Details) | Aug. 31, 2024 | |
| Schwab Treasury Inflation Protected Securities Index Fund [Member] | AAA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [1] |
| Schwab Treasury Inflation Protected Securities Index Fund [Member] | AA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 99.90% | [1] |
| Schwab Treasury Inflation Protected Securities Index Fund [Member] | Treasuries [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 99.90% | |
| Schwab Treasury Inflation Protected Securities Index Fund [Member] | Short-Term Investments [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [2] |
| Schwab U.S. Aggregate Bond Index Fund [Member] | AAA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.80% | [1] |
| Schwab U.S. Aggregate Bond Index Fund [Member] | AA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 70.80% | [1] |
| Schwab U.S. Aggregate Bond Index Fund [Member] | A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 11.20% | [1] |
| Schwab U.S. Aggregate Bond Index Fund [Member] | BBB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.20% | [1] |
| Schwab U.S. Aggregate Bond Index Fund [Member] | Unrated Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0% | [1],[3] |
| Schwab U.S. Aggregate Bond Index Fund [Member] | Treasuries [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 42.70% | |
| Schwab U.S. Aggregate Bond Index Fund [Member] | Short-Term Investments [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.90% | [2] |
| Schwab U.S. Aggregate Bond Index Fund [Member] | Securitized [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 27.10% | [4] |
| Schwab U.S. Aggregate Bond Index Fund [Member] | Corporates [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 23.90% | |
| Schwab U.S. Aggregate Bond Index Fund [Member] | Government Related [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.40% | |
| Schwab Short-Term Bond Index Fund [Member] | AAA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4% | [1] |
| Schwab Short-Term Bond Index Fund [Member] | AA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 71.70% | [1] |
| Schwab Short-Term Bond Index Fund [Member] | A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.20% | [1] |
| Schwab Short-Term Bond Index Fund [Member] | BBB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.10% | [1] |
| Schwab Short-Term Bond Index Fund [Member] | Treasuries [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 67.70% | |
| Schwab Short-Term Bond Index Fund [Member] | Short-Term Investments [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.80% | [2] |
| Schwab Short-Term Bond Index Fund [Member] | Corporates [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 25.10% | |
| Schwab Short-Term Bond Index Fund [Member] | Government Related [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.40% | |
| Schwab Tax-Free Bond Fund [Member] | AAA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 10.40% | [1] |
| Schwab Tax-Free Bond Fund [Member] | AA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 26.80% | [1] |
| Schwab Tax-Free Bond Fund [Member] | A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 44% | [1] |
| Schwab Tax-Free Bond Fund [Member] | BBB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 15.60% | [1] |
| Schwab Tax-Free Bond Fund [Member] | Unrated Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.40% | [1] |
| Schwab Tax-Free Bond Fund [Member] | BB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.80% | [1] |
| Schwab Tax-Free Bond Fund [Member] | Revenue Bonds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 74.10% | |
| Schwab Tax-Free Bond Fund [Member] | General Obligation Bonds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 20.80% | |
| Schwab Tax-Free Bond Fund [Member] | Other [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.60% | |
| Schwab Tax-Free Bond Fund [Member] | Pre Refunded Bonds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| Schwab California Tax-Free Bond Fund | AAA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | [1] |
| Schwab California Tax-Free Bond Fund | AA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 55.90% | [1] |
| Schwab California Tax-Free Bond Fund | A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 28.20% | [1] |
| Schwab California Tax-Free Bond Fund | BBB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 11.70% | [1] |
| Schwab California Tax-Free Bond Fund | Unrated Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.40% | [1] |
| Schwab California Tax-Free Bond Fund | BB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.60% | [1] |
| Schwab California Tax-Free Bond Fund | Revenue Bonds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 68.40% | |
| Schwab California Tax-Free Bond Fund | General Obligation Bonds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 23.20% | |
| Schwab California Tax-Free Bond Fund | Other [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.80% | |
| Schwab California Tax-Free Bond Fund | Pre Refunded Bonds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.60% | |
| Schwab Opportunistic Municipal Bond Fund [Member] | AAA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 7.80% | [1] |
| Schwab Opportunistic Municipal Bond Fund [Member] | AA [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 31.60% | [1] |
| Schwab Opportunistic Municipal Bond Fund [Member] | A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 31.60% | [1] |
| Schwab Opportunistic Municipal Bond Fund [Member] | BBB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 24.20% | [1] |
| Schwab Opportunistic Municipal Bond Fund [Member] | Unrated Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.30% | [1] |
| Schwab Opportunistic Municipal Bond Fund [Member] | BB [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | [1] |
| Schwab Opportunistic Municipal Bond Fund [Member] | Revenue Bonds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 76% | |
| Schwab Opportunistic Municipal Bond Fund [Member] | General Obligation Bonds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 19.30% | |
| Schwab Opportunistic Municipal Bond Fund [Member] | Other [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.70% | |
| [1]Bloomberg Index Rating: Based on the middle rating of Moody’s, S&P and Fitch; when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. In cases where explicit bond level ratings may not be available, other sources may be used to classify securities by credit quality. Source: Bloomberg Index Service Ltd.[2]Includes the fund’s position(s) in money market mutual funds registered under the Investment Company Act of 1940, as amended.[3]Less than 0.05%.[4]The fund may seek to obtain exposure to U.S. agency mortgage pass-through securities, in part or in full, through the use of “to-be-announced” or “TBA” transactions, which are standardized contracts for future delivery of mortgage pass-through securities in which the exact mortgage pools to be delivered are not specified until a few days prior to settlement. These transactions represented approximately 1.1% of net assets on August 31, 2024. | ||
