| Form N-CSR Cover | 6 Months Ended |
| Jun. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | Fidelity Hanover Street Trust |
| Entity Central Index Key | 0000702533 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Jun. 30, 2024 |
| Shareholder Report | 6 Months Ended |
| Jun. 30, 2024 USD ($) shares | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | Fidelity Hanover Street Trust |
| Entity Central Index Key | 0000702533 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Jun. 30, 2024 |
| Fidelity Emerging Markets Debt Central Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Emerging Markets Debt Central Fund |
| Class Name | Fidelity® Emerging Markets Debt Central Fund |
| No Trading Symbol Flag | true |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Emerging Markets Debt Central Fund for the period January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544. |
| Additional Information Phone Number | 1-800-544-8544 |
| Additional Information Website | fundresearch.fidelity.com/prospectus/sec |
| Expenses [Text Block] | What were your Fund costs for the last six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Emerging Markets Debt Central Fund $ 0.02 % |
| Expenses Paid, Amount | $ 1 |
| Expense Ratio, Percent | 0.02% |
| Net Assets | $ 2,114,976,064 |
| Holdings Count | shares | 508 |
| Investment Company Portfolio Turnover | 15% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of June 30, 2024) KEY FACTS Fund Size $ Number of Holdings 508 Portfolio Turnover 15 % |
| Holdings [Text Block] | U.S. Government and U.S. Government Agency Obligations 5.0 AA 6.8 A 9.3 BBB 20.6 BB 24.0 B 17.2 CCC,CC,C 10.5 D 0.1 Not Rated 3.8 Equities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 2.7 QUALITY DIVERSIFICATION (% of Fund's net assets) We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes. Foreign Government and Government Agency Obligations 45.0 Corporate Bonds 44.0 U.S. Treasury Obligations 5.0 Preferred Securities 3.3 Common Stocks 0.0 Short-Term Investments and Net Other Assets (Liabilities) 2.7 ASSET ALLOCATION (% of Fund's net assets) Mexico 9.0 United States 7.9 Brazil 7.2 Saudi Arabia 5.4 Turkey 4.9 United Arab Emirates 4.6 Colombia 4.3 Indonesia 4.0 Chile 3.9 Others 48.8 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Republic of Turkiye/The 4.2 Petroleos Mexicanos 3.4 US Treasury Bonds 3.3 Argentine Republic 2.9 Indonesia Government 2.3 Dominican Republic 2.3 Saudi Arabian Oil Co 2.0 United Mexican States 1.9 State of Qatar 1.8 Colombian Republic 1.8 25.9 |
| Fidelity Emerging Markets Debt Local Currency Central Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Emerging Markets Debt Local Currency Central Fund |
| Class Name | Fidelity® Emerging Markets Debt Local Currency Central Fund |
| No Trading Symbol Flag | true |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Emerging Markets Debt Local Currency Central Fund for the period January 1, 2024 to June 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544. |
| Additional Information Phone Number | 1-800-544-8544 |
| Additional Information Website | fundresearch.fidelity.com/prospectus/sec |
| Expenses [Text Block] | What were your Fund costs for the last six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Emerging Markets Debt Local Currency Central Fund $ 0.02 % |
| Expenses Paid, Amount | $ 1 |
| Expense Ratio, Percent | 0.02% |
| Net Assets | $ 259,672,836 |
| Holdings Count | shares | 235 |
| Investment Company Portfolio Turnover | 50% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of June 30, 2024) KEY FACTS Fund Size $ Number of Holdings 235 Portfolio Turnover 50 % |
| Holdings [Text Block] | AAA 1.1 AA 4.9 A 4.2 BBB 18.6 BB 12.9 Not Rated 43.3 Short-Term Investments and Net Other Assets (Liabilities) 15.0 QUALITY DIVERSIFICATION (% of Fund's net assets) We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes. Foreign Government and Government Agency Obligations 83.1 Corporate Bonds 1.4 U.S. Treasury Obligations 0.5 Short-Term Investments and Net Other Assets (Liabilities) 15.0 ASSET ALLOCATION (% of Fund's net assets) United States 15.5 Malaysia 10.1 Mexico 9.5 Brazil 9.2 South Africa 8.4 Indonesia 8.4 Poland 4.7 China 4.7 Czech Republic 4.6 Others 24.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Malaysia Government 10.1 United Mexican States 9.5 South African Republic 8.4 Indonesia Government 8.4 Republic of Poland 4.7 Peoples Republic of China 4.7 Czech Republic 4.6 Romanian Republic 4.6 Brazil Notas do Tesouro Nacional Serie F 4.4 Colombian Republic 4.4 63.8 |
| Shareholder Report, Holdings (Details) | Jun. 30, 2024 |
| Fidelity Emerging Markets Debt Central Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| Fidelity Emerging Markets Debt Central Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| Fidelity Emerging Markets Debt Central Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Emerging Markets Debt Central Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.90% |
| Fidelity Emerging Markets Debt Central Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Emerging Markets Debt Central Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Emerging Markets Debt Central Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| Fidelity Emerging Markets Debt Central Fund | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Emerging Markets Debt Central Fund | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| Fidelity Emerging Markets Debt Central Fund | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| Fidelity Emerging Markets Debt Central Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5% |
| Fidelity Emerging Markets Debt Central Fund | QDAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| Fidelity Emerging Markets Debt Central Fund | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.60% |
| Fidelity Emerging Markets Debt Central Fund | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24% |
| Fidelity Emerging Markets Debt Central Fund | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.20% |
| Fidelity Emerging Markets Debt Central Fund | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.50% |
| Fidelity Emerging Markets Debt Central Fund | QDDMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.10% |
| Fidelity Emerging Markets Debt Central Fund | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Emerging Markets Debt Central Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| Fidelity Emerging Markets Debt Central Fund | Mexico | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9% |
| Fidelity Emerging Markets Debt Central Fund | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.90% |
| Fidelity Emerging Markets Debt Central Fund | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.20% |
| Fidelity Emerging Markets Debt Central Fund | Saudi Arabia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.40% |
| Fidelity Emerging Markets Debt Central Fund | Turkey | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Fidelity Emerging Markets Debt Central Fund | United Arab Emirates | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| Fidelity Emerging Markets Debt Central Fund | Colombia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Fidelity Emerging Markets Debt Central Fund | Indonesia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Emerging Markets Debt Central Fund | Chile | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Fidelity Emerging Markets Debt Central Fund | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 48.80% |
| Fidelity Emerging Markets Debt Central Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 45% |
| Fidelity Emerging Markets Debt Central Fund | AACorporateBondsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44% |
| Fidelity Emerging Markets Debt Central Fund | AAUSTreasuryObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5% |
| Fidelity Emerging Markets Debt Central Fund | AAPreferredSecuritiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Emerging Markets Debt Central Fund | AACommonStocksMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Emerging Markets Debt Central Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.10% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.50% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.40% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.40% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | QDAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.60% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 43.30% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | Mexico | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.50% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.50% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | Indonesia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.90% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | Malaysia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.10% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | South Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | Poland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | China | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.70% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | Czech Republic | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 83.10% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | AACorporateBondsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | AAUSTreasuryObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.50% |
| Fidelity Emerging Markets Debt Local Currency Central Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15% |
| Label | Element | Value |
| C000222143 [Member] | QDAAMember [Member] | ||
| Percent of Net Asset Value | oef_PctOfNav | 4.90% |
| C000222143 [Member] | QDAAAMember [Member] | ||
| Percent of Net Asset Value | oef_PctOfNav | 1.10% |
| C000101068 [Member] | QDEquitiesMember [Member] | ||
| Percent of Net Asset Value | oef_PctOfNav | 0% |
| C000101068 [Member] | QDAAMember [Member] | ||
| Percent of Net Asset Value | oef_PctOfNav | 6.80% |
