| Form N-CSR Cover | 6 Months Ended |
| Jun. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | Chestnut Street Exchange Fund |
| Entity Central Index Key | 0000019780 |
| 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 | Chestnut Street Exchange Fund |
| Entity Central Index Key | 0000019780 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Jun. 30, 2024 |
| Chestnut Street Exchange Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Chestnut Street Exchange Fund |
| Class Name | Chestnut Street Exchange Fund |
| Trading Symbol | CHNTX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Chestnut Street Exchange Fund (the “Fund”) for the period of 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 https://funddocs.filepoint.com/chestnutstreet/ . You can also request this information by contacting us at 1-866-311-7541 . |
| Additional Information Phone Number | 1-866-311-7541 |
| Additional Information Website | https://funddocs.filepoint.com/chestnutstreet/ |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment) Fund Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Chestnut Street Exchange Fund $26 0.50% |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.50% |
| Updated Performance Information Location [Text Block] | Visit https://funddocs.filepoint.com/chestnutstreet/ for more recent performance information. |
| Net Assets | $ 170,410,636 |
| Holdings Count | $ / shares | 38 |
| Investment Company Portfolio Turnover | 0% |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of June 30, 2024) Net Assets $170,410,636 Number of Holdings 38 Portfolio Turnover Rate 0% |
| Holdings [Text Block] | Top Sectors (% of Net Assets) Information Technology 25.9% Financials 13.6% Health Care 12.8% Industrials 11.1% Communication Services 10.5% Materials 7.6% Consumer Staples 6.5% Consumer Discretionary 6.0% Energy 4.8% Cash & Other 1.2% Top 10 Issuers (% of Net Assets) Microsoft Corp. 8.6% Apple, Inc. 6.6% JPMorgan Chase & Co. 5.5% Moody’s Corp. 5.3% Abbott Laboratories 4.8% Union Pacific Corp. 4.8% Alphabet, Inc. 4.5% Air Products and Chemicals, Inc. 4.3% Oracle Corp. 4.1% Emerson Electric Co. 4.1% |
| Updated Prospectus Web Address | https://funddocs.filepoint.com/chestnutstreet/. |
| Shareholder Report, Holdings (Details) - Chestnut Street Exchange Fund | Jun. 30, 2024 |
| Microsoft Corp. [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Apple, Inc. [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| JPMorgan Chase & Co. [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Moodys Corp. [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Abbott Laboratories [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Union Pacific Corp. [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Alphabet, Inc. [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| Air Products and Chemicals, Inc. [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Oracle Corp. [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.10% |
| Emerson Electric Co. [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.10% |
| Information Technology [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25.90% |
| Financials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.60% |
| Health Care [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.80% |
| Industrials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.10% |
| Communication Services [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.50% |
| Materials [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| Consumer Staples [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| Consumer Discretionary [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| Energy [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Cash & Other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
