| Form N-CSR Cover | 12 Months Ended |
| Sep. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | Vanguard Malvern Funds |
| Entity Central Index Key | 0000836906 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| Shareholder Report | 12 Months Ended |
| Sep. 30, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | Vanguard Malvern Funds |
| Entity Central Index Key | 0000836906 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| C000118815 | |
| Shareholder Report [Line Items] | |
| Fund Name | Short-Term Inflation-Protected Securities Index Fund |
| Class Name | ETF Shares |
| Trading Symbol | VTIP |
| Security Exchange Name | NASDAQ |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Vanguard Short-Term Inflation-Protected Securities Index Fund (the "Fund") for the period of October 1, 2023, to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature. You can also request this information by contacting us at 800-662-7447. |
| Additional Information Phone Number | 800-662-7447 |
| Additional Information Website | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Share Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment ETF Shares $4 0.04% |
| Expenses Paid, Amount | $ 4 |
| Expense Ratio, Percent | 0.04% |
| Factors Affecting Performance [Text Block] | How did the Fund perform during the reporting period? For the 12 months ended September 30, 2024, the Fund performed in line with its benchmark, the Bloomberg U.S. 0–5 Year Treasury Inflation Protected Securities Index. U.S. economic growth hovered around 3% on a year-over-year basis during the period, quelling recession fears. The Federal Reserve began cutting interest rates for the first time since early 2020, and the year-over-year rate of consumer price inflation eased to around 2.5%. The Bloomberg U.S. Aggregate Bond Index of investment-grade bonds returned about 11.6%. Bond prices and yields move in opposite directions, and short-term TIPS prices got a boost during the period from falling U.S. Treasury yields. The yield of the 2-year note, for example, fell to 3.64%, from 5.04% a year earlier. Inflation expectations cooled. The five-year break-even inflation rate—which implies the markets’ expectation for the annualized rate of inflation over the coming five years—ended the period at 2.07%. It started the Fund’s fiscal year at 2.22% and peaked during the period at 2.52%. |
| Line Graph [Table Text Block] | ETF Shares Net Asset Value Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index Bloomberg U.S. Aggregate Bond Index 2014 $10,000 $10,000 $10,000 2014 $9,851 $9,849 $10,179 2015 $9,884 $9,886 $10,343 2015 $9,935 $9,946 $10,169 2015 $9,874 $9,881 $10,294 2015 $9,837 $9,847 $10,235 2016 $10,015 $10,026 $10,546 2016 $10,098 $10,111 $10,779 2016 $10,125 $10,140 $10,829 2016 $10,104 $10,124 $10,506 2017 $10,174 $10,195 $10,592 2017 $10,120 $10,143 $10,745 2017 $10,165 $10,192 $10,836 2017 $10,187 $10,213 $10,879 2018 $10,207 $10,234 $10,720 2018 $10,258 $10,284 $10,703 2018 $10,268 $10,295 $10,705 2018 $10,241 $10,273 $10,880 2019 $10,415 $10,443 $11,200 2019 $10,582 $10,615 $11,545 2019 $10,623 $10,650 $11,807 2019 $10,736 $10,771 $11,828 2020 $10,659 $10,697 $12,200 2020 $10,939 $10,978 $12,554 2020 $11,126 $11,170 $12,632 2020 $11,270 $11,317 $12,716 2021 $11,392 $11,438 $12,287 2021 $11,584 $11,631 $12,512 2021 $11,736 $11,783 $12,518 2021 $11,869 $11,921 $12,520 2022 $11,835 $11,886 $11,777 2022 $11,701 $11,755 $11,224 2022 $11,394 $11,447 $10,691 2022 $11,533 $11,595 $10,891 2023 $11,794 $11,848 $11,214 2023 $11,715 $11,767 $11,119 2023 $11,767 $11,818 $10,760 2023 $12,066 $12,124 $11,493 2024 $12,167 $12,227 $11,404 2024 $12,345 $12,399 $11,411 2024 $12,654 $12,707 $12,004 |
| Average Annual Return [Table Text Block] | 1 Year 5 Years 10 Years ETF Shares Net Asset Value 7.53% 3.56% 2.38% ETF Shares Market Price 7.52% 3.55% 2.38% Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index 7.53% 3.60% 2.42% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.84% |
| AssetsNet | $ 54,073,000,000 |
| Holdings Count | Holding | 28 |
| Advisory Fees Paid, Amount | $ 1,372,000 |
| InvestmentCompanyPortfolioTurnover | 26% |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of September 30, 2024 Fund Net Assets (in millions) $54,073 Number of Portfolio Holdings 28 Portfolio Turnover Rate 26% Total Investment Advisory Fees (in thousands) $1,372 |
| Holdings [Text Block] | This table reflects the Fund's investments, including short-term investments and other assets and liabilities. Distribution by Stated Maturity % of Net Assets (as of September 30, 2024) Less than 1 Year 20.3% 1 to 3 Years 36.7% 3 to 5 Years 42.5% Other Assets and Liabilities—Net 0.5% |
| Material Fund Change [Text Block] | |
| Updated Prospectus Web Address | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| C000118814 | |
| Shareholder Report [Line Items] | |
| Fund Name | Short-Term Inflation-Protected Securities Index Fund |
| Class Name | Admiral™ Shares |
| Trading Symbol | VTAPX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Vanguard Short-Term Inflation-Protected Securities Index Fund (the "Fund") for the period of October 1, 2023, to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature. You can also request this information by contacting us at 800-662-7447. |
| Additional Information Phone Number | 800-662-7447 |
| Additional Information Website | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Share Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Admiral Shares $6 0.06% |
| Expenses Paid, Amount | $ 6 |
| Expense Ratio, Percent | 0.06% |
| Factors Affecting Performance [Text Block] | How did the Fund perform during the reporting period? For the 12 months ended September 30, 2024, the Fund performed in line with its benchmark, the Bloomberg U.S. 0–5 Year Treasury Inflation Protected Securities Index. U.S. economic growth hovered around 3% on a year-over-year basis during the period, quelling recession fears. The Federal Reserve began cutting interest rates for the first time since early 2020, and the year-over-year rate of consumer price inflation eased to around 2.5%. The Bloomberg U.S. Aggregate Bond Index of investment-grade bonds returned about 11.6%. Bond prices and yields move in opposite directions, and short-term TIPS prices got a boost during the period from falling U.S. Treasury yields. The yield of the 2-year note, for example, fell to 3.64%, from 5.04% a year earlier. Inflation expectations cooled. The five-year break-even inflation rate—which implies the markets’ expectation for the annualized rate of inflation over the coming five years—ended the period at 2.07%. It started the Fund’s fiscal year at 2.22% and peaked during the period at 2.52%. |
| Line Graph [Table Text Block] | Admiral Shares Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index Bloomberg U.S. Aggregate Bond Index 2014 $10,000 $10,000 $10,000 2014 $9,854 $9,849 $10,179 2015 $9,886 $9,886 $10,343 2015 $9,939 $9,946 $10,169 2015 $9,878 $9,881 $10,294 2015 $9,838 $9,847 $10,235 2016 $10,017 $10,026 $10,546 2016 $10,102 $10,111 $10,779 2016 $10,127 $10,140 $10,829 2016 $10,105 $10,124 $10,506 2017 $10,175 $10,195 $10,592 2017 $10,121 $10,143 $10,745 2017 $10,167 $10,192 $10,836 2017 $10,188 $10,213 $10,879 2018 $10,209 $10,234 $10,720 2018 $10,258 $10,284 $10,703 2018 $10,268 $10,295 $10,705 2018 $10,242 $10,273 $10,880 2019 $10,417 $10,443 $11,200 2019 $10,585 $10,615 $11,545 2019 $10,623 $10,650 $11,807 2019 $10,738 $10,771 $11,828 2020 $10,660 $10,697 $12,200 2020 $10,938 $10,978 $12,554 2020 $11,124 $11,170 $12,632 2020 $11,272 $11,317 $12,716 2021 $11,393 $11,438 $12,287 2021 $11,583 $11,631 $12,512 2021 $11,733 $11,783 $12,518 2021 $11,864 $11,921 $12,520 2022 $11,834 $11,886 $11,777 2022 $11,695 $11,755 $11,224 2022 $11,390 $11,447 $10,691 2022 $11,529 $11,595 $10,891 2023 $11,791 $11,848 $11,214 2023 $11,709 $11,767 $11,119 2023 $11,764 $11,818 $10,760 2023 $12,058 $12,124 $11,493 2024 $12,161 $12,227 $11,404 2024 $12,339 $12,399 $11,411 2024 $12,642 $12,707 $12,004 |
| Average Annual Return [Table Text Block] | 1 Year 5 Years 10 Years Admiral Shares 7.46% 3.54% 2.37% Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index 7.53% 3.60% 2.42% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.84% |
| AssetsNet | $ 54,073,000,000 |
| Holdings Count | Holding | 28 |
| Advisory Fees Paid, Amount | $ 1,372,000 |
| InvestmentCompanyPortfolioTurnover | 26% |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of September 30, 2024 Fund Net Assets (in millions) $54,073 Number of Portfolio Holdings 28 Portfolio Turnover Rate 26% Total Investment Advisory Fees (in thousands) $1,372 |
| Holdings [Text Block] | This table reflects the Fund's investments, including short-term investments and other assets and liabilities. Distribution by Stated Maturity % of Net Assets (as of September 30, 2024) Less than 1 Year 20.3% 1 to 3 Years 36.7% 3 to 5 Years 42.5% Other Assets and Liabilities—Net 0.5% |
| Material Fund Change [Text Block] | |
| Updated Prospectus Web Address | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| C000118816 | |
| Shareholder Report [Line Items] | |
| Fund Name | Short-Term Inflation-Protected Securities Index Fund |
| Class Name | Institutional Shares |
| Trading Symbol | VTSPX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Vanguard Short-Term Inflation-Protected Securities Index Fund (the "Fund") for the period of October 1, 2023, to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature. You can also request this information by contacting us at 800-662-7447. |
| Additional Information Phone Number | 800-662-7447 |
| Additional Information Website | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Share Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Institutional Shares $4 0.04% |
| Expenses Paid, Amount | $ 4 |
| Expense Ratio, Percent | 0.04% |
| Factors Affecting Performance [Text Block] | How did the Fund perform during the reporting period? For the 12 months ended September 30, 2024, the Fund performed in line with its benchmark, the Bloomberg U.S. 0–5 Year Treasury Inflation Protected Securities Index. U.S. economic growth hovered around 3% on a year-over-year basis during the period, quelling recession fears. The Federal Reserve began cutting interest rates for the first time since early 2020, and the year-over-year rate of consumer price inflation eased to around 2.5%. The Bloomberg U.S. Aggregate Bond Index of investment-grade bonds returned about 11.6%. Bond prices and yields move in opposite directions, and short-term TIPS prices got a boost during the period from falling U.S. Treasury yields. The yield of the 2-year note, for example, fell to 3.64%, from 5.04% a year earlier. Inflation expectations cooled. The five-year break-even inflation rate—which implies the markets’ expectation for the annualized rate of inflation over the coming five years—ended the period at 2.07%. It started the Fund’s fiscal year at 2.22% and peaked during the period at 2.52%. |
| Line Graph [Table Text Block] | Institutional Shares Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index Bloomberg U.S. Aggregate Bond Index 2014 $5,000,000 $5,000,000 $5,000,000 2014 $4,928,353 $4,924,481 $5,089,712 2015 $4,942,596 $4,943,208 $5,171,483 2015 $4,969,049 $4,972,857 $5,084,467 2015 $4,940,562 $4,940,644 $5,147,040 2015 $4,920,213 $4,923,419 $5,117,703 2016 $5,009,746 $5,012,760 $5,272,871 2016 $5,052,477 $5,055,321 $5,389,599 2016 $5,066,721 $5,069,938 $5,414,297 2016 $5,056,205 $5,061,929 $5,253,193 2017 $5,091,076 $5,097,295 $5,296,098 2017 $5,066,461 $5,071,617 $5,372,635 2017 $5,089,024 $5,095,840 $5,418,223 2017 $5,098,053 $5,106,308 $5,439,253 2018 $5,108,466 $5,117,148 $5,359,795 2018 $5,135,520 $5,141,912 $5,351,310 2018 $5,140,722 $5,147,504 $5,352,334 2018 $5,128,029 $5,136,389 $5,439,871 2019 $5,215,524 $5,221,440 $5,599,958 2019 $5,298,037 $5,307,554 $5,772,417 2019 $5,319,456 $5,324,792 $5,903,406 2019 $5,375,062 $5,385,504 $5,914,048 2020 $5,338,067 $5,348,512 $6,100,243 2020 $5,477,340 $5,489,017 $6,276,880 2020 $5,571,262 $5,585,088 $6,315,751 2020 $5,643,028 $5,658,380 $6,357,994 2021 $5,704,186 $5,718,868 $6,143,571 2021 $5,801,720 $5,815,636 $6,255,983 2021 $5,876,953 $5,891,663 $6,259,222 2021 $5,943,196 $5,960,596 $6,259,951 2022 $5,925,754 $5,943,012 $5,888,485 2022 $5,859,089 $5,877,381 $5,612,108 2022 $5,704,169 $5,723,333 $5,345,399 2022 $5,776,499 $5,797,366 $5,445,523 2023 $5,908,196 $5,924,159 $5,606,821 2023 $5,867,583 $5,883,583 $5,559,482 2023 $5,892,847 $5,908,767 $5,379,845 2023 $6,043,067 $6,062,217 $5,746,597 2024 $6,094,674 $6,113,494 $5,702,020 2024 $6,181,628 $6,199,480 $5,705,733 2024 $6,336,451 $6,353,472 $6,002,211 |
| Average Annual Return [Table Text Block] | 1 Year 5 Years 10 Years Institutional Shares 7.53% 3.56% 2.40% Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index 7.53% 3.60% 2.42% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.84% |
| AssetsNet | $ 54,073,000,000 |
| Holdings Count | Holding | 28 |
| Advisory Fees Paid, Amount | $ 1,372,000 |
| InvestmentCompanyPortfolioTurnover | 26% |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of September 30, 2024 Fund Net Assets (in millions) $54,073 Number of Portfolio Holdings 28 Portfolio Turnover Rate 26% Total Investment Advisory Fees (in thousands) $1,372 |
| Holdings [Text Block] | This table reflects the Fund's investments, including short-term investments and other assets and liabilities. Distribution by Stated Maturity % of Net Assets (as of September 30, 2024) Less than 1 Year 20.3% 1 to 3 Years 36.7% 3 to 5 Years 42.5% Other Assets and Liabilities—Net 0.5% |
| Material Fund Change [Text Block] | |
| Updated Prospectus Web Address | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| C000118817 | |
| Shareholder Report [Line Items] | |
| Fund Name | Short-Term Inflation-Protected Securities Index Fund |
| Class Name | Investor Shares |
| Trading Symbol | VTIPX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Vanguard Short-Term Inflation-Protected Securities Index Fund (the "Fund") for the period of October 1, 2023, to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature. You can also request this information by contacting us at 800-662-7447. |
| Additional Information Phone Number | 800-662-7447 |
| Additional Information Website | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Share Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Investor Shares $15 0.14% |
| Expenses Paid, Amount | $ 15 |
| Expense Ratio, Percent | 0.14% |
| Factors Affecting Performance [Text Block] | How did the Fund perform during the reporting period? For the 12 months ended September 30, 2024, the Fund performed in line with its benchmark, the Bloomberg U.S. 0–5 Year Treasury Inflation Protected Securities Index. U.S. economic growth hovered around 3% on a year-over-year basis during the period, quelling recession fears. The Federal Reserve began cutting interest rates for the first time since early 2020, and the year-over-year rate of consumer price inflation eased to around 2.5%. The Bloomberg U.S. Aggregate Bond Index of investment-grade bonds returned about 11.6%. Bond prices and yields move in opposite directions, and short-term TIPS prices got a boost during the period from falling U.S. Treasury yields. The yield of the 2-year note, for example, fell to 3.64%, from 5.04% a year earlier. Inflation expectations cooled. The five-year break-even inflation rate—which implies the markets’ expectation for the annualized rate of inflation over the coming five years—ended the period at 2.07%. It started the Fund’s fiscal year at 2.22% and peaked during the period at 2.52%. |
| Line Graph [Table Text Block] | Investor Shares Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index Bloomberg U.S. Aggregate Bond Index 2014 $10,000 $10,000 $10,000 2014 $9,848 $9,849 $10,179 2015 $9,880 $9,886 $10,343 2015 $9,929 $9,946 $10,169 2015 $9,864 $9,881 $10,294 2015 $9,827 $9,847 $10,235 2016 $10,002 $10,026 $10,546 2016 $10,084 $10,111 $10,779 2016 $10,108 $10,140 $10,829 2016 $10,082 $10,124 $10,506 2017 $10,147 $10,195 $10,592 2017 $10,094 $10,143 $10,745 2017 $10,139 $10,192 $10,836 2017 $10,154 $10,213 $10,879 2018 $10,175 $10,234 $10,720 2018 $10,224 $10,284 $10,703 2018 $10,232 $10,295 $10,705 2018 $10,204 $10,273 $10,880 2019 $10,374 $10,443 $11,200 2019 $10,540 $10,615 $11,545 2019 $10,575 $10,650 $11,807 2019 $10,688 $10,771 $11,828 2020 $10,606 $10,697 $12,200 2020 $10,883 $10,978 $12,554 2020 $11,066 $11,170 $12,632 2020 $11,206 $11,317 $12,716 2021 $11,325 $11,438 $12,287 2021 $11,516 $11,631 $12,512 2021 $11,662 $11,783 $12,518 2021 $11,790 $11,921 $12,520 2022 $11,753 $11,886 $11,777 2022 $11,618 $11,755 $11,224 2022 $11,311 $11,447 $10,691 2022 $11,447 $11,595 $10,891 2023 $11,705 $11,848 $11,214 2023 $11,621 $11,767 $11,119 2023 $11,674 $11,818 $10,760 2023 $11,963 $12,124 $11,493 2024 $12,062 $12,227 $11,404 2024 $12,236 $12,399 $11,411 2024 $12,540 $12,707 $12,004 |
| Average Annual Return [Table Text Block] | 1 Year 5 Years 10 Years Investor Shares 7.42% 3.47% 2.29% Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index 7.53% 3.60% 2.42% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.84% |
| AssetsNet | $ 54,073,000,000 |
| Holdings Count | Holding | 28 |
| Advisory Fees Paid, Amount | $ 1,372,000 |
| InvestmentCompanyPortfolioTurnover | 26% |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of September 30, 2024 Fund Net Assets (in millions) $54,073 Number of Portfolio Holdings 28 Portfolio Turnover Rate 26% Total Investment Advisory Fees (in thousands) $1,372 |
| Holdings [Text Block] | This table reflects the Fund's investments, including short-term investments and other assets and liabilities. Distribution by Stated Maturity % of Net Assets (as of September 30, 2024) Less than 1 Year 20.3% 1 to 3 Years 36.7% 3 to 5 Years 42.5% Other Assets and Liabilities—Net 0.5% |
| Material Fund Change [Text Block] | |
| Updated Prospectus Web Address | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| C000166997 | |
| Shareholder Report [Line Items] | |
| Fund Name | Emerging Markets Bond Fund |
| Class Name | Admiral™ Shares |
| Trading Symbol | VEGBX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Vanguard Emerging Markets Bond Fund (the "Fund") for the period of October 1, 2023, to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature. You can also request this information by contacting us at 800-662-7447. |
| Additional Information Phone Number | 800-662-7447 |
| Additional Information Website | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Share Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Admiral Shares $44 0.40% |
| Expenses Paid, Amount | $ 44 |
| Expense Ratio, Percent | 0.40% |
| Factors Affecting Performance [Text Block] | How did the Fund perform during the reporting period? For the 12 months ended September 30, 2024, the Fund outperformed its benchmark, the JP Morgan EMBI Global Diversified Index. Global economic growth appeared relatively stable at around 3% during the period and U.S. recession fears faded. With inflation continuing to moderate across much of the world, major central banks including the European Central Bank, the Bank of England, and the U.S. Federal Reserve began lowering policy rates. The Bloomberg Global Aggregate Index of investment-grade bonds returned about 12%. In late 2023, our down-in-quality positioning paid off as yields on emerging-market high-yield sovereign bonds narrowed relative to yields of investment-grade sovereign bonds. And in early 2024, we benefited from a wave of issuance to add exposure to higher-quality sovereign bonds at attractive levels. |
| Line Graph [Table Text Block] | Admiral Shares JP Morgan EMBI Global Diversified Index 12/6/17 $50,000 $50,000 12/31/17 $50,216 $50,185 3/31/18 $50,020 $49,309 6/30/18 $48,975 $47,562 9/30/18 $50,458 $48,657 12/31/18 $49,865 $48,047 3/31/19 $54,187 $51,387 6/30/19 $56,583 $53,482 9/30/19 $57,283 $54,287 12/31/19 $58,773 $55,271 3/31/20 $52,741 $47,875 6/30/20 $61,232 $53,745 9/30/20 $63,518 $54,989 12/31/20 $67,687 $58,177 3/31/21 $65,030 $55,536 6/30/21 $67,789 $57,790 9/30/21 $67,348 $57,386 12/31/21 $66,846 $57,133 3/31/22 $61,402 $51,407 6/30/22 $54,393 $45,529 9/30/22 $52,942 $43,450 12/31/22 $58,144 $46,973 3/31/23 $59,621 $47,848 6/30/23 $61,138 $48,893 9/30/23 $60,591 $47,801 12/31/23 $66,169 $52,182 3/31/24 $67,825 $53,245 6/30/24 $67,973 $53,406 9/30/24 $72,140 $56,693 |
| Average Annual Return [Table Text Block] | 1 Year 5 Years Since Inception 12/6/2017 Admiral Shares 19.06% 4.72% 5.52% JP Morgan EMBI Global Diversified Index 18.60% 0.87% 1.86% |
| AssetsNet | $ 3,646,000,000 |
| Holdings Count | Holding | 333 |
| Advisory Fees Paid, Amount | $ 515,000 |
| InvestmentCompanyPortfolioTurnover | 137% |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of September 30, 2024 Fund Net Assets (in millions) $3,646 Number of Portfolio Holdings 333 Portfolio Turnover Rate 137% Total Investment Advisory Fees (in thousands) $515 |
| Holdings [Text Block] | This table reflects the Fund's investments, including short-term investments, derivatives and other assets and liabilities. Portfolio Composition % of Net Assets (as of September 30, 2024 Asia 24.0% South America 23.9% North America 19.5% Africa 13.1% Europe 12.4% Other Assets and Liabilities—Net 7.1% |
| Material Fund Change [Text Block] | |
| Updated Prospectus Web Address | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| C000166998 | |
| Shareholder Report [Line Items] | |
| Fund Name | Emerging Markets Bond Fund |
| Class Name | Investor Shares |
| Trading Symbol | VEMBX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about Vanguard Emerging Markets Bond Fund (the "Fund") for the period of October 1, 2023, to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund at https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature. You can also request this information by contacting us at 800-662-7447. |
| Additional Information Phone Number | 800-662-7447 |
| Additional Information Website | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Share Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Investor Shares $60 0.55% |
| Expenses Paid, Amount | $ 60 |
| Expense Ratio, Percent | 0.55% |
| Factors Affecting Performance [Text Block] | How did the Fund perform during the reporting period? For the 12 months ended September 30, 2024, the Fund outperformed its benchmark, the JP Morgan EMBI Global Diversified Index. Global economic growth appeared relatively stable at around 3% during the period and U.S. recession fears faded. With inflation continuing to moderate across much of the world, major central banks including the European Central Bank, the Bank of England, and the U.S. Federal Reserve began lowering policy rates. The Bloomberg Global Aggregate Index of investment-grade bonds returned about 12%. In late 2023, our down-in-quality positioning paid off as yields on emerging-market high-yield sovereign bonds narrowed relative to yields of investment-grade sovereign bonds. And in early 2024, we benefited from a wave of issuance to add exposure to higher-quality sovereign bonds at attractive levels. |
| Line Graph [Table Text Block] | Investor Shares JP Morgan EMBI Global Diversified Index 3/10/16 $10,000 $10,000 3/31/16 $10,154 $10,192 6/30/16 $10,746 $10,703 9/30/16 $11,351 $11,136 12/31/16 $10,936 $10,688 3/31/17 $11,427 $11,101 6/30/17 $11,752 $11,350 9/30/17 $12,147 $11,649 12/31/17 $12,395 $11,784 3/31/18 $12,343 $11,578 6/30/18 $12,074 $11,168 9/30/18 $12,437 $11,425 12/31/18 $12,286 $11,282 3/31/19 $13,352 $12,066 6/30/19 $13,932 $12,558 9/30/19 $14,104 $12,747 12/31/19 $14,462 $12,978 3/31/20 $12,972 $11,241 6/30/20 $15,064 $12,620 9/30/20 $15,608 $12,912 12/31/20 $16,629 $13,660 3/31/21 $15,978 $13,040 6/30/21 $16,645 $13,570 9/30/21 $16,531 $13,475 12/31/21 $16,403 $13,415 3/31/22 $15,055 $12,071 6/30/22 $13,338 $10,691 9/30/22 $12,975 $10,202 12/31/22 $14,242 $11,030 3/31/23 $14,604 $11,235 6/30/23 $14,965 $11,480 9/30/23 $14,831 $11,224 12/31/23 $16,185 $12,253 3/31/24 $16,586 $12,502 6/30/24 $16,605 $12,540 9/30/24 $17,631 $13,312 |
| Average Annual Return [Table Text Block] | 1 Year 5 Years Since Inception 3/10/2016 Investor Shares 18.88% 4.57% 6.85% JP Morgan EMBI Global Diversified Index 18.60% 0.87% 3.40% |
| AssetsNet | $ 3,646,000,000 |
| Holdings Count | Holding | 333 |
| Advisory Fees Paid, Amount | $ 515,000 |
| InvestmentCompanyPortfolioTurnover | 137% |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of September 30, 2024 Fund Net Assets (in millions) $3,646 Number of Portfolio Holdings 333 Portfolio Turnover Rate 137% Total Investment Advisory Fees (in thousands) $515 |
| Holdings [Text Block] | This table reflects the Fund's investments, including short-term investments, derivatives and other assets and liabilities. Portfolio Composition % of Net Assets (as of September 30, 2024 Asia 24.0% South America 23.9% North America 19.5% Africa 13.1% Europe 12.4% Other Assets and Liabilities—Net 7.1% |
| Material Fund Change [Text Block] | |
| Updated Prospectus Web Address | https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature |
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||
| Sep. 30, 2024 | Jun. 30, 2024 | Mar. 31, 2024 | Dec. 31, 2023 | Sep. 30, 2023 | Jun. 30, 2023 | Mar. 31, 2023 | Dec. 31, 2022 | Sep. 30, 2022 | Jun. 30, 2022 | Mar. 31, 2022 | Dec. 31, 2021 | Sep. 30, 2021 | Jun. 30, 2021 | Mar. 31, 2021 | Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2017 | Dec. 06, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Mar. 10, 2016 | Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2014 | Sep. 30, 2014 | |
| C000118815 | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | ETF Shares Net Asset Value | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,654 | $ 12,345 | $ 12,167 | $ 12,066 | $ 11,767 | $ 11,715 | $ 11,794 | $ 11,533 | $ 11,394 | $ 11,701 | $ 11,835 | $ 11,869 | $ 11,736 | $ 11,584 | $ 11,392 | $ 11,270 | $ 11,126 | $ 10,939 | $ 10,659 | $ 10,736 | $ 10,623 | $ 10,582 | $ 10,415 | $ 10,241 | $ 10,268 | $ 10,258 | $ 10,207 | $ 10,187 | $ 10,165 | $ 10,120 | $ 10,174 | $ 10,104 | $ 10,125 | $ 10,098 | $ 10,015 | $ 9,837 | $ 9,874 | $ 9,935 | $ 9,884 | $ 9,851 | $ 10,000 | ||
| C000118814 | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Admiral Shares | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,642 | 12,339 | 12,161 | 12,058 | 11,764 | 11,709 | 11,791 | 11,529 | 11,390 | 11,695 | 11,834 | 11,864 | 11,733 | 11,583 | 11,393 | 11,272 | 11,124 | 10,938 | 10,660 | 10,738 | 10,623 | 10,585 | 10,417 | 10,242 | 10,268 | 10,258 | 10,209 | 10,188 | 10,167 | 10,121 | 10,175 | 10,105 | 10,127 | 10,102 | 10,017 | 9,838 | 9,878 | 9,939 | 9,886 | 9,854 | 10,000 | ||
| C000118816 | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Institutional Shares | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 6,336,451 | 6,181,628 | 6,094,674 | 6,043,067 | 5,892,847 | 5,867,583 | 5,908,196 | 5,776,499 | 5,704,169 | 5,859,089 | 5,925,754 | 5,943,196 | 5,876,953 | 5,801,720 | 5,704,186 | 5,643,028 | 5,571,262 | 5,477,340 | 5,338,067 | 5,375,062 | 5,319,456 | 5,298,037 | 5,215,524 | 5,128,029 | 5,140,722 | 5,135,520 | 5,108,466 | 5,098,053 | 5,089,024 | 5,066,461 | 5,091,076 | 5,056,205 | 5,066,721 | 5,052,477 | 5,009,746 | 4,920,213 | 4,940,562 | 4,969,049 | 4,942,596 | 4,928,353 | 5,000,000 | ||
| C000118817 | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Investor Shares | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,540 | 12,236 | 12,062 | 11,963 | 11,674 | 11,621 | 11,705 | 11,447 | 11,311 | 11,618 | 11,753 | 11,790 | 11,662 | 11,516 | 11,325 | 11,206 | 11,066 | 10,883 | 10,606 | 10,688 | 10,575 | 10,540 | 10,374 | 10,204 | 10,232 | 10,224 | 10,175 | 10,154 | 10,139 | 10,094 | 10,147 | 10,082 | 10,108 | 10,084 | 10,002 | 9,827 | 9,864 | 9,929 | 9,880 | 9,848 | 10,000 | ||
| C000166997 | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 72,140 | 67,973 | 67,825 | 66,169 | 60,591 | 61,138 | 59,621 | 58,144 | 52,942 | 54,393 | 61,402 | 66,846 | 67,348 | 67,789 | 65,030 | 67,687 | 63,518 | 61,232 | 52,741 | 58,773 | 57,283 | 56,583 | 54,187 | 49,865 | 50,458 | 48,975 | 50,020 | 50,216 | $ 50,000 | ||||||||||||||
| C000166998 | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Investor Shares | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 17,631 | 16,605 | 16,586 | 16,185 | 14,831 | 14,965 | 14,604 | 14,242 | 12,975 | 13,338 | 15,055 | 16,403 | 16,531 | 16,645 | 15,978 | 16,629 | 15,608 | 15,064 | 12,972 | 14,462 | 14,104 | 13,932 | 13,352 | 12,286 | 12,437 | 12,074 | 12,343 | 12,395 | 12,147 | 11,752 | 11,427 | 10,936 | 11,351 | 10,746 | 10,154 | $ 10,000 | |||||||
| NACC2 Index: Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,707 | 12,399 | 12,227 | 12,124 | 11,818 | 11,767 | 11,848 | 11,595 | 11,447 | 11,755 | 11,886 | 11,921 | 11,783 | 11,631 | 11,438 | 11,317 | 11,170 | 10,978 | 10,697 | 10,771 | 10,650 | 10,615 | 10,443 | 10,273 | 10,295 | 10,284 | 10,234 | 10,213 | 10,192 | 10,143 | 10,195 | 10,124 | 10,140 | 10,111 | 10,026 | 9,847 | 9,881 | 9,946 | 9,886 | 9,849 | 10,000 | ||
| NACC2 Index: Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,707 | 12,399 | 12,227 | 12,124 | 11,818 | 11,767 | 11,848 | 11,595 | 11,447 | 11,755 | 11,886 | 11,921 | 11,783 | 11,631 | 11,438 | 11,317 | 11,170 | 10,978 | 10,697 | 10,771 | 10,650 | 10,615 | 10,443 | 10,273 | 10,295 | 10,284 | 10,234 | 10,213 | 10,192 | 10,143 | 10,195 | 10,124 | 10,140 | 10,111 | 10,026 | 9,847 | 9,881 | 9,946 | 9,886 | 9,849 | 10,000 | ||
| NACC2 Index: Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 6,353,472 | 6,199,480 | 6,113,494 | 6,062,217 | 5,908,767 | 5,883,583 | 5,924,159 | 5,797,366 | 5,723,333 | 5,877,381 | 5,943,012 | 5,960,596 | 5,891,663 | 5,815,636 | 5,718,868 | 5,658,380 | 5,585,088 | 5,489,017 | 5,348,512 | 5,385,504 | 5,324,792 | 5,307,554 | 5,221,440 | 5,136,389 | 5,147,504 | 5,141,912 | 5,117,148 | 5,106,308 | 5,095,840 | 5,071,617 | 5,097,295 | 5,061,929 | 5,069,938 | 5,055,321 | 5,012,760 | 4,923,419 | 4,940,644 | 4,972,857 | 4,943,208 | 4,924,481 | 5,000,000 | ||
| NACC2 Index: Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,707 | 12,399 | 12,227 | 12,124 | 11,818 | 11,767 | 11,848 | 11,595 | 11,447 | 11,755 | 11,886 | 11,921 | 11,783 | 11,631 | 11,438 | 11,317 | 11,170 | 10,978 | 10,697 | 10,771 | 10,650 | 10,615 | 10,443 | 10,273 | 10,295 | 10,284 | 10,234 | 10,213 | 10,192 | 10,143 | 10,195 | 10,124 | 10,140 | 10,111 | 10,026 | 9,847 | 9,881 | 9,946 | 9,886 | 9,849 | 10,000 | ||
| NACC2 Index: JP Morgan EMBI Global Diversified Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 56,693 | 53,406 | 53,245 | 52,182 | 47,801 | 48,893 | 47,848 | 46,973 | 43,450 | 45,529 | 51,407 | 57,133 | 57,386 | 57,790 | 55,536 | 58,177 | 54,989 | 53,745 | 47,875 | 55,271 | 54,287 | 53,482 | 51,387 | 48,047 | 48,657 | 47,562 | 49,309 | 50,185 | $ 50,000 | ||||||||||||||
| NACC2 Index: JP Morgan EMBI Global Diversified Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | JP Morgan EMBI Global Diversified Index | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 13,312 | 12,540 | 12,502 | 12,253 | 11,224 | 11,480 | 11,235 | 11,030 | 10,202 | 10,691 | 12,071 | 13,415 | 13,475 | 13,570 | 13,040 | 13,660 | 12,912 | 12,620 | 11,241 | 12,978 | 12,747 | 12,558 | 12,066 | 11,282 | 11,425 | 11,168 | 11,578 | 11,784 | 11,649 | 11,350 | 11,101 | 10,688 | 11,136 | 10,703 | 10,192 | $ 10,000 | |||||||
| NACC2 Index: Bloomberg U.S. Aggregate Bond Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,004 | 11,411 | 11,404 | 11,493 | 10,760 | 11,119 | 11,214 | 10,891 | 10,691 | 11,224 | 11,777 | 12,520 | 12,518 | 12,512 | 12,287 | 12,716 | 12,632 | 12,554 | 12,200 | 11,828 | 11,807 | 11,545 | 11,200 | 10,880 | 10,705 | 10,703 | 10,720 | 10,879 | 10,836 | 10,745 | 10,592 | 10,506 | 10,829 | 10,779 | 10,546 | 10,235 | 10,294 | 10,169 | 10,343 | 10,179 | 10,000 | ||
| NACC2 Index: Bloomberg U.S. Aggregate Bond Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,004 | 11,411 | 11,404 | 11,493 | 10,760 | 11,119 | 11,214 | 10,891 | 10,691 | 11,224 | 11,777 | 12,520 | 12,518 | 12,512 | 12,287 | 12,716 | 12,632 | 12,554 | 12,200 | 11,828 | 11,807 | 11,545 | 11,200 | 10,880 | 10,705 | 10,703 | 10,720 | 10,879 | 10,836 | 10,745 | 10,592 | 10,506 | 10,829 | 10,779 | 10,546 | 10,235 | 10,294 | 10,169 | 10,343 | 10,179 | 10,000 | ||
| NACC2 Index: Bloomberg U.S. Aggregate Bond Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 6,002,211 | 5,705,733 | 5,702,020 | 5,746,597 | 5,379,845 | 5,559,482 | 5,606,821 | 5,445,523 | 5,345,399 | 5,612,108 | 5,888,485 | 6,259,951 | 6,259,222 | 6,255,983 | 6,143,571 | 6,357,994 | 6,315,751 | 6,276,880 | 6,100,243 | 5,914,048 | 5,903,406 | 5,772,417 | 5,599,958 | 5,439,871 | 5,352,334 | 5,351,310 | 5,359,795 | 5,439,253 | 5,418,223 | 5,372,635 | 5,296,098 | 5,253,193 | 5,414,297 | 5,389,599 | 5,272,871 | 5,117,703 | 5,147,040 | 5,084,467 | 5,171,483 | 5,089,712 | 5,000,000 | ||
| NACC2 Index: Bloomberg U.S. Aggregate Bond Index | |||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | ||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,004 | $ 11,411 | $ 11,404 | $ 11,493 | $ 10,760 | $ 11,119 | $ 11,214 | $ 10,891 | $ 10,691 | $ 11,224 | $ 11,777 | $ 12,520 | $ 12,518 | $ 12,512 | $ 12,287 | $ 12,716 | $ 12,632 | $ 12,554 | $ 12,200 | $ 11,828 | $ 11,807 | $ 11,545 | $ 11,200 | $ 10,880 | $ 10,705 | $ 10,703 | $ 10,720 | $ 10,879 | $ 10,836 | $ 10,745 | $ 10,592 | $ 10,506 | $ 10,829 | $ 10,779 | $ 10,546 | $ 10,235 | $ 10,294 | $ 10,169 | $ 10,343 | $ 10,179 | $ 10,000 |
| Shareholder Report, Average Annual Return (Details) | 12 Months Ended | 60 Months Ended | 82 Months Ended | 103 Months Ended | 120 Months Ended |
| Sep. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2024 | |
| C000118815 | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | ETF Shares Net Asset Value | ||||
| Average Annual Return, Percent | 7.52% | 3.55% | 2.38% | ||
| C000118814 | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Admiral Shares | ||||
| C000118816 | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Institutional Shares | ||||
| C000118817 | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Investor Shares | ||||
| C000166998 | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Investor Shares | ||||
| Without Sales Load [Member] | C000118815 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 7.53% | 3.56% | 2.38% | ||
| Without Sales Load [Member] | C000118814 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 7.46% | 3.54% | 2.37% | ||
| Without Sales Load [Member] | C000118816 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 7.53% | 3.56% | 2.40% | ||
| Without Sales Load [Member] | C000118817 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 7.42% | 3.47% | 2.29% | ||
| Without Sales Load [Member] | C000166997 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 19.06% | 4.72% | 5.52% | ||
| Without Sales Load [Member] | C000166998 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 18.88% | 4.57% | 6.85% | ||
| NACC2 Index: Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | ||||
| Average Annual Return, Percent | 7.53% | 3.60% | 2.42% | ||
| NACC2 Index: Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | ||||
| Average Annual Return, Percent | 7.53% | 3.60% | 2.42% | ||
| NACC2 Index: Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | ||||
| Average Annual Return, Percent | 7.53% | 3.60% | 2.42% | ||
| NACC2 Index: Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg U.S. 0-5 Year Treasury Inflation Protected Securities Index | ||||
| Average Annual Return, Percent | 7.53% | 3.60% | 2.42% | ||
| NACC2 Index: JP Morgan EMBI Global Diversified Index | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 18.60% | 0.87% | 1.86% | ||
| NACC2 Index: JP Morgan EMBI Global Diversified Index | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | JP Morgan EMBI Global Diversified Index | ||||
| Average Annual Return, Percent | 18.60% | 0.87% | 3.40% | ||
| NACC2 Index: Bloomberg U.S. Aggregate Bond Index | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | ||||
| Average Annual Return, Percent | 11.57% | 0.33% | 1.84% | ||
| NACC2 Index: Bloomberg U.S. Aggregate Bond Index | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | ||||
| Average Annual Return, Percent | 11.57% | 0.33% | 1.84% | ||
| NACC2 Index: Bloomberg U.S. Aggregate Bond Index | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | ||||
| Average Annual Return, Percent | 11.57% | 0.33% | 1.84% | ||
| NACC2 Index: Bloomberg U.S. Aggregate Bond Index | |||||
| Average Annual Return [Line Items] | |||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | ||||
| Average Annual Return, Percent | 11.57% | 0.33% | 1.84% |
| Shareholder Report, Holdings (Details) | Sep. 30, 2024 |
| C000118815 | Less than 1 Year | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.30% |
| C000118815 | 1 to 3 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.70% |
| C000118815 | 3 to 5 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.50% |
| C000118815 | Other Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.50% |
| C000118814 | Less than 1 Year | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.30% |
| C000118814 | 1 to 3 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.70% |
| C000118814 | 3 to 5 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.50% |
| C000118814 | Other Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.50% |
| C000118816 | Less than 1 Year | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.30% |
| C000118816 | 1 to 3 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.70% |
| C000118816 | 3 to 5 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.50% |
| C000118816 | Other Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.50% |
| C000118817 | Less than 1 Year | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.30% |
| C000118817 | 1 to 3 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.70% |
| C000118817 | 3 to 5 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.50% |
| C000118817 | Other Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.50% |
| C000166997 | Asia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24% |
| C000166997 | South America | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.90% |
| C000166997 | North America | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.50% |
| C000166997 | Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.10% |
| C000166997 | Europe | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| C000166997 | Country Other Net Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.10% |
| C000166998 | Asia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24% |
| C000166998 | South America | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.90% |
| C000166998 | North America | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.50% |
| C000166998 | Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.10% |
| C000166998 | Europe | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| C000166998 | Country Other Net Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.10% |
