v3.25.2
Shareholder Report
 6 Months Ended
May 31, 2025
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Vanguard New Jersey Tax-Free Funds
Entity Central Index Key 0000821404
Entity Investment Company Type N-1A
Document Period End Date May 31, 2025
C000007964  
Shareholder Report [Line Items]  
Fund Name New Jersey Long-Term Tax-Exempt Fund
Class Name Investor Shares
Trading Symbol VNJTX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Vanguard New Jersey Long-Term Tax-Exempt Fund (the "Fund") for the period of December 1, 2024, to May 31, 2025.
Shareholder Report Annual or Semi-Annual Semi-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 six months?

(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
$7
0.15%Footnote Reference1
FootnoteDescription
Footnote1
Annualized.
Expenses Paid, Amount $ 7
Expense Ratio, Percent 0.15% [1]
AssetsNet $ 2,583,000,000
Holdings Count | Holding 926
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Fund Statistics (as of May 31, 2025)

Fund Net Assets (in millions)
$2,583
Number of Portfolio Holdings
926
Portfolio Turnover Rate
15%
Holdings [Text Block]

Distribution by Stated Maturity % of Net Assets (as of May 31, 2025) 

Less than 1 Year
6.5%
1 to 3 Years
3.8%
3 to 5 Years
3.3%
5 to 10 Years
12.5%
10 to 20 Years
37.1%
20 to 30 Years
31.5%
Greater than 30 Years
5.1%
Other Assets and Liabilities—Net
0.2%

This table reflects the Fund's investments, including short-term investments, derivatives and other assets and liabilities.
Material Fund Change [Text Block]
Updated Prospectus Phone Number 800-662-7447
Updated Prospectus Web Address https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature
C000007965  
Shareholder Report [Line Items]  
Fund Name New Jersey Long-Term Tax-Exempt Fund
Class Name Admiral™ Shares
Trading Symbol VNJUX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Vanguard New Jersey Long-Term Tax-Exempt Fund (the "Fund") for the period of December 1, 2024, to May 31, 2025.
Shareholder Report Annual or Semi-Annual Semi-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 six months?

(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
$4
0.09%Footnote Reference1
FootnoteDescription
Footnote1
Annualized.
Expenses Paid, Amount $ 4
Expense Ratio, Percent 0.09% [2]
AssetsNet $ 2,583,000,000
Holdings Count | Holding 926
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Fund Statistics (as of May 31, 2025)

Fund Net Assets (in millions)
$2,583
Number of Portfolio Holdings
926
Portfolio Turnover Rate
15%
Holdings [Text Block]

Distribution by Stated Maturity % of Net Assets (as of May 31, 2025) 

Less than 1 Year
6.5%
1 to 3 Years
3.8%
3 to 5 Years
3.3%
5 to 10 Years
12.5%
10 to 20 Years
37.1%
20 to 30 Years
31.5%
Greater than 30 Years
5.1%
Other Assets and Liabilities—Net
0.2%

This table reflects the Fund's investments, including short-term investments, derivatives and other assets and liabilities.
Material Fund Change [Text Block]
Updated Prospectus Phone Number 800-662-7447
Updated Prospectus Web Address https://personal1.vanguard.com/ngf-next-gen-form-webapp/fund-literature
[1] Annualized.
[2] Annualized.