v3.26.1
Shareholder Report
 6 Months Ended
Jun. 30, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name FENIMORE ASSET MANAGEMENT TRUST
Entity Central Index Key 0000797136
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2026
Shareholder Report Annual or Semi-Annual Semi-Annual Shareholder Report
C000030126  
Shareholder Report [Line Items]  
Fund Name FAM VALUE FUND
Class Name INVESTOR SHARES
Trading Symbol FAMVX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about FAM Value Fund (the "Fund") for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://fenimoreasset.com/resources/reports/ . You can also request this information by contacting us at (800) 932-3271.
Additional Information Phone Number (800) 932-3271
Additional Information Email <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 700; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">info@fenimoreasset.com</span>
Additional Information Website https://fenimoreasset.com/resources/reports/
Expenses [Text Block]

What were the Fund’s Annualized costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Investor Shares
$60
1.17%
Expenses Paid, Amount $ 60
Expense Ratio, Percent 1.17%
Performance Past Does Not Indicate Future [Text] The Fund's past performance is not a good predictor of how the Fund will perform in the future.
Line Graph [Table Text Block]
Growth of 10K Chart
Table Summary
FAM Value Fund - Investor Shares
S&P 500® Index
Russell Midcap® Index
Jun-2016
$10,000
$10,000
$10,000
Jun-2017
$11,568
$11,790
$11,648
Jun-2018
$12,912
$13,484
$13,084
Jun-2019
$14,517
$14,889
$14,108
Jun-2020
$13,864
$16,006
$13,792
Jun-2021
$19,325
$22,536
$20,660
Jun-2022
$16,716
$20,144
$17,087
Jun-2023
$19,410
$24,091
$19,637
Jun-2024
$22,226
$30,006
$22,165
Jun-2025
$25,415
$34,556
$25,536
Jun-2026
$27,494
$42,271
$31,060
Average Annual Return [Table Text Block]
Table Summary
6 Months
1 Year
5 Years
10 Years
FAM Value Fund - Investor Shares
7.91%
8.18%
7.31%
10.64%
S&P 500® Index
10.21%
22.32%
13.41%
15.51%
Russell Midcap® Index
15.30%
21.63%
8.50%
12.00%
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Updated Performance Information Location [Text Block] Call (800) 932-3271 or visit https://fenimoreasset.com/solutions/mutual-funds/fam-value-fund/ for updated performance information.
AssetsNet $ 1,818,087,566
Holdings Count | Holding 32
Advisory Fees Paid, Amount $ 7,885,151
InvestmentCompanyPortfolioTurnover 6.00%
Additional Fund Statistics [Text Block]

Fund Statistics 

  • Net Assets$1,818,087,566
  • Number of Portfolio Holdings32
  • Advisory Fee (net of waivers)$7,885,151
  • Portfolio turnover6%
Holdings [Text Block]

Portfolio Composition (% of net assets)

Group By Sector Chart
Table Summary
Value
Value
Other
0.3%
Professional Services
0.6%
Diversified Financial Services
0.7%
Software
1.0%
Money Market Funds
1.1%
Banks
2.2%
Road & Rail
2.2%
Life Sciences Tools & Services
2.3%
Hotels, Restaurants & Leisure
2.8%
Health Care Equipment & Supplies
3.6%
Trading Companies & Distributors
4.1%
Construction Materials
4.8%
Capital Markets
7.5%
Semiconductors & Semiconductor Equipment
7.6%
Specialty Retail
10.0%
Machinery
11.8%
Insurance
16.9%
Electronic Equipment, Instruments & Components
20.5%
Largest Holdings [Text Block]

Top 10 Holdings (% of net assets)

Table Summary
Holding Name
% of Net Assets
Ross Stores, Inc.
6.8%
Amphenol Corporation - Class A
6.6%
Analog Devices, Inc.
6.3%
Markel Group, Inc.
5.8%
IDEX Corporation
5.4%
Keysight Technologies, Inc.
5.0%
Brookfield Corporation - Class A
4.9%
Vulcan Materials Company
4.8%
Brown & Brown, Inc.
4.4%
Fastenal Company
4.1%
Material Fund Change [Text Block]

No material changes occurred during the period ended June 30, 2026. 
C000164665  
Shareholder Report [Line Items]  
Fund Name FAM VALUE FUND
Class Name INSTITUTIONAL SHARES
Trading Symbol FAMWX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about FAM Value Fund (the "Fund") for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://fenimoreasset.com/resources/reports/ . You can also request this information by contacting us at (800) 932-3271.
Additional Information Phone Number (800) 932-3271
Additional Information Email <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 700; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">info@fenimoreasset.com</span>
Additional Information Website https://fenimoreasset.com/resources/reports/
Expenses [Text Block]

What were the Fund’s Annualized costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Institutional Shares
$51
0.99%
Expenses Paid, Amount $ 51
Expense Ratio, Percent 0.99%
Performance Past Does Not Indicate Future [Text] The Fund's past performance is not a good predictor of how the Fund will perform in the future.
Line Graph [Table Text Block]
Growth of 10K Chart
Table Summary
FAM Value Fund - Institutional Shares
S&P 500® Index
Russell Midcap® Index
Jun-2016
$500,000
$500,000
$500,000
Jun-2017
$578,875
$589,481
$582,419
Jun-2018
$647,274
$674,213
$654,207
Jun-2019
$728,999
$744,449
$705,400
Jun-2020
$697,626
$800,320
$689,600
Jun-2021
$974,110
$1,126,804
$1,033,012
Jun-2022
$844,281
$1,007,185
$854,340
Jun-2023
$982,172
$1,204,533
$981,846
Jun-2024
$1,126,707
$1,500,319
$1,108,263
Jun-2025
$1,290,885
$1,727,822
$1,276,779
Jun-2026
$1,398,798
$2,113,559
$1,552,996
Average Annual Return [Table Text Block]
Table Summary
6 Months
1 Year
5 Years
10 Years
FAM Value Fund - Institutional Shares
7.99%
8.36%
7.51%
10.84%
S&P 500® Index
10.21%
22.32%
13.41%
15.51%
Russell Midcap® Index
15.30%
21.63%
8.50%
12.00%
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Updated Performance Information Location [Text Block] Call (800) 932-3271 or visit https://fenimoreasset.com/solutions/mutual-funds/fam-value-fund/ for updated performance information.
AssetsNet $ 1,818,087,566
Holdings Count | Holding 32
Advisory Fees Paid, Amount $ 7,885,151
InvestmentCompanyPortfolioTurnover 6.00%
Additional Fund Statistics [Text Block]

Fund Statistics 

  • Net Assets$1,818,087,566
  • Number of Portfolio Holdings32
  • Advisory Fee (net of waivers)$7,885,151
  • Portfolio turnover6%
Holdings [Text Block]

Portfolio Composition (% of net assets)

Group By Sector Chart
Table Summary
Value
Value
Other
0.3%
Professional Services
0.6%
Diversified Financial Services
0.7%
Software
1.0%
Money Market Funds
1.1%
Banks
2.2%
Road & Rail
2.2%
Life Sciences Tools & Services
2.3%
Hotels, Restaurants & Leisure
2.8%
Health Care Equipment & Supplies
3.6%
Trading Companies & Distributors
4.1%
Construction Materials
4.8%
Capital Markets
7.5%
Semiconductors & Semiconductor Equipment
7.6%
Specialty Retail
10.0%
Machinery
11.8%
Insurance
16.9%
Electronic Equipment, Instruments & Components
20.5%
Largest Holdings [Text Block]

Top 10 Holdings (% of net assets)

Table Summary
Holding Name
% of Net Assets
Ross Stores, Inc.
6.8%
Amphenol Corporation - Class A
6.6%
Analog Devices, Inc.
6.3%
Markel Group, Inc.
5.8%
IDEX Corporation
5.4%
Keysight Technologies, Inc.
5.0%
Brookfield Corporation - Class A
4.9%
Vulcan Materials Company
4.8%
Brown & Brown, Inc.
4.4%
Fastenal Company
4.1%
Material Fund Change [Text Block]

No material changes occurred during the period ended June 30, 2026. 
C000030128  
Shareholder Report [Line Items]  
Fund Name FAM DIVIDEND FOCUS FUND
Class Name INVESTOR SHARES
Trading Symbol FAMEX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about FAM Dividend Focus Fund (the "Fund") for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://fenimoreasset.com/resources/reports/ . You can also request this information by contacting us at (800) 932-3271.
Additional Information Phone Number (800) 932-3271
Additional Information Email <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 700; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">info@fenimoreasset.com</span>
Additional Information Website https://fenimoreasset.com/resources/reports/
Expenses [Text Block]

What were the Fund’s Annualized costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Investor Shares
$62
1.23%
Expenses Paid, Amount $ 62
Expense Ratio, Percent 1.23%
Performance Past Does Not Indicate Future [Text] The Fund's past performance is not a good predictor of how the Fund will perform in the future.
Line Graph [Table Text Block]
Growth of 10K Chart
Table Summary
FAM Dividend Focus Fund - Investor Shares
S&P 500® Index
Russell Midcap® Index
Jun-2016
$10,000
$10,000
$10,000
Jun-2017
$11,696
$11,790
$11,648
Jun-2018
$13,004
$13,484
$13,084
Jun-2019
$15,558
$14,889
$14,108
Jun-2020
$15,246
$16,006
$13,792
Jun-2021
$21,449
$22,536
$20,660
Jun-2022
$18,722
$20,144
$17,087
Jun-2023
$22,799
$24,091
$19,637
Jun-2024
$26,423
$30,006
$22,165
Jun-2025
$28,411
$34,556
$25,536
Jun-2026
$27,668
$42,271
$31,060
Average Annual Return [Table Text Block]
Table Summary
6 Months
1 Year
5 Years
10 Years
FAM Dividend Focus Fund - Investor Shares
2.57%
-2.61%
5.22%
10.71%
S&P 500® Index
10.21%
22.32%
13.41%
15.51%
Russell Midcap® Index
15.30%
21.63%
8.50%
12.00%
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Updated Performance Information Location [Text Block] Call (800) 932-3271 or visit https://fenimoreasset.com/solutions/mutual-funds/fam-dividend-focus-fund/ for updated performance information.
AssetsNet $ 635,786,114
Holdings Count | Holding 29
Advisory Fees Paid, Amount $ 2,947,937
InvestmentCompanyPortfolioTurnover 8.00%
Additional Fund Statistics [Text Block]

Fund Statistics 

  • Net Assets$635,786,114
  • Number of Portfolio Holdings29
  • Advisory Fee $2,947,937
  • Portfolio turnover8%
Holdings [Text Block]

Portfolio Composition (% of net assets)

Group By Sector Chart
Table Summary
Value
Value
Other
0.2%
Real Estate Management & Development
0.3%
Communications Equipment
1.5%
Containers & Packaging
2.0%
Textiles, Apparel & Luxury Goods
2.3%
Money Market Funds
2.6%
Professional Services
2.8%
Machinery
2.8%
Capital Markets
3.5%
Trading Companies & Distributors
4.5%
Electronic Equipment, Instruments & Components
4.5%
IT Services
5.7%
Insurance
6.2%
Specialty Retail
6.6%
Aerospace & Defense
6.8%
Building Products
8.9%
Health Care Equipment & Supplies
9.2%
Construction Materials
9.6%
Semiconductors & Semiconductor Equipment
9.7%
Commercial Services & Supplies
10.3%
Largest Holdings [Text Block]

Top 10 Holdings (% of net assets)

Table Summary
Holding Name
% of Net Assets
Trane Technologies plc
8.9%
HEICO Corporation - Class A
6.8%
Ross Stores, Inc.
6.6%
Arthur J. Gallagher & Company
6.2%
Stryker Corporation
5.3%
Microchip Technology, Inc.
5.1%
Republic Services, Inc.
5.0%
Martin Marietta Materials, Inc.
5.0%
Entegris, Inc.
4.6%
Vulcan Materials Company
4.6%
Material Fund Change [Text Block]

No material changes occurred during the period ended June 30, 2026. 
C000110096  
Shareholder Report [Line Items]  
Fund Name FAM SMALL CAP FUND
Class Name INVESTOR SHARES
Trading Symbol FAMFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about FAM Small Cap Fund (the "Fund") for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://fenimoreasset.com/resources/reports/ . You can also request this information by contacting us at (800) 932-3271.
Additional Information Phone Number (800) 932-3271
Additional Information Email <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 700; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">info@fenimoreasset.com</span>
Additional Information Website https://fenimoreasset.com/resources/reports/
Expenses [Text Block]

What were the Fund’s Annualized costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Investor Shares
$63
1.27%
Expenses Paid, Amount $ 63
Expense Ratio, Percent 1.27%
Performance Past Does Not Indicate Future [Text] The Fund's past performance is not a good predictor of how the Fund will perform in the future.
Line Graph [Table Text Block]
Growth of 10K Chart
Table Summary
FAM Small Cap Fund - Investor Shares
S&P 500® Index
Russell 2000® Index
Jun-2016
$10,000
$10,000
$10,000
Jun-2017
$11,585
$11,790
$12,460
Jun-2018
$12,781
$13,484
$14,649
Jun-2019
$12,693
$14,889
$14,164
Jun-2020
$11,710
$16,006
$13,226
Jun-2021
$18,046
$22,536
$21,429
Jun-2022
$16,473
$20,144
$16,029
Jun-2023
$18,974
$24,091
$18,002
Jun-2024
$20,537
$30,006
$19,812
Jun-2025
$22,450
$34,556
$21,334
Jun-2026
$20,141
$42,271
$30,034
Average Annual Return [Table Text Block]
Table Summary
6 Months
1 Year
5 Years
10 Years
FAM Small Cap Fund - Investor Shares
-1.46%
-10.28%
2.22%
7.25%
S&P 500® Index
10.21%
22.32%
13.41%
15.51%
Russell 2000® Index
22.57%
40.78%
6.98%
11.62%
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Updated Performance Information Location [Text Block] Call (800) 932-3271 or visit https://fenimoreasset.com/solutions/mutual-funds/fam-small-cap-fund/ for updated performance information.
AssetsNet $ 310,630,106
Holdings Count | Holding 26
Advisory Fees Paid, Amount $ 1,437,055
InvestmentCompanyPortfolioTurnover 11.00%
Additional Fund Statistics [Text Block]

Fund Statistics 

  • Net Assets$310,630,106
  • Number of Portfolio Holdings26
  • Advisory Fee $1,437,055
  • Portfolio turnover11%
Holdings [Text Block]

Portfolio Composition (% of net assets)

Group By Sector Chart
Table Summary
Value
Value
Other
-0.2%
Hotels, Restaurants & Leisure
2.7%
Media
3.2%
Road & Rail
3.3%
Gas Utilities
3.3%
Banks
3.7%
Chemicals
3.9%
Money Market Funds
4.1%
Health Care Providers & Services
4.1%
Trading Companies & Distributors
4.2%
Specialty Retail
4.4%
Building Products
4.4%
Electrical Equipment
4.5%
Software
5.5%
Machinery
6.8%
Diversified Consumer Services
7.9%
Real Estate Management & Development
8.6%
Insurance
12.6%
Professional Services
13.0%
Largest Holdings [Text Block]

Top 10 Holdings (% of net assets)

Table Summary
Holding Name
% of Net Assets
CBIZ, Inc.
5.6%
Baldwin Insurance Group, Inc. (The)
5.3%
Frontdoor, Inc.
4.7%
Colliers International Group, Inc.
4.6%
Novanta, Inc.
4.5%
Floor & Decor Holdings, Inc. - Class A
4.4%
Casella Waste Systems, Inc. - Class A
4.3%
SiteOne Landscape Supply, Inc.
4.2%
Trisura Group Ltd.
4.1%
Chemed Corporation
4.1%
Material Fund Change [Text Block]

No material changes occurred during the period ended June 30, 2026. 
C000164667  
Shareholder Report [Line Items]  
Fund Name FAM SMALL CAP FUND
Class Name INSTITUTIONAL SHARES
Trading Symbol FAMDX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about FAM Small Cap Fund (the "Fund") for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://fenimoreasset.com/resources/reports/ . You can also request this information by contacting us at (800) 932-3271.
Additional Information Phone Number (800) 932-3271
Additional Information Email <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 700; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">info@fenimoreasset.com</span>
Additional Information Website https://fenimoreasset.com/resources/reports/
Expenses [Text Block]

What were the Fund’s Annualized costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Institutional Shares
$58
1.17%
Expenses Paid, Amount $ 58
Expense Ratio, Percent 1.17%
Performance Past Does Not Indicate Future [Text] The Fund's past performance is not a good predictor of how the Fund will perform in the future.
Line Graph [Table Text Block]
Growth of 10K Chart
Table Summary
FAM Small Cap Fund - Institutional Shares
S&P 500® Index
Russell 2000® Index
Jun-2016
$500,000
$500,000
$500,000
Jun-2017
$580,135
$589,481
$623,004
Jun-2018
$640,944
$674,213
$732,440
Jun-2019
$637,230
$744,449
$708,201
Jun-2020
$588,500
$800,320
$661,282
Jun-2021
$907,501
$1,126,804
$1,071,446
Jun-2022
$829,378
$1,007,185
$801,469
Jun-2023
$956,532
$1,204,533
$900,103
Jun-2024
$1,036,171
$1,500,319
$990,619
Jun-2025
$1,133,700
$1,727,822
$1,066,711
Jun-2026
$1,017,723
$2,113,559
$1,501,703
Average Annual Return [Table Text Block]
Table Summary
6 Months
1 Year
5 Years
10 Years
FAM Small Cap Fund - Institutional Shares
-1.44%
-10.23%
2.32%
7.37%
S&P 500® Index
10.21%
22.32%
13.41%
15.51%
Russell 2000® Index
22.57%
40.78%
6.98%
11.62%
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Updated Performance Information Location [Text Block] Call (800) 932-3271 or visit https://fenimoreasset.com/solutions/mutual-funds/fam-small-cap-fund/ for updated performance information.
AssetsNet $ 310,630,106
Holdings Count | Holding 26
Advisory Fees Paid, Amount $ 1,437,055
InvestmentCompanyPortfolioTurnover 11.00%
Additional Fund Statistics [Text Block]

Fund Statistics 

  • Net Assets$310,630,106
  • Number of Portfolio Holdings26
  • Advisory Fee $1,437,055
  • Portfolio turnover11%
Holdings [Text Block]

Portfolio Composition (% of net assets)

Group By Sector Chart
Table Summary
Value
Value
Other
-0.2%
Hotels, Restaurants & Leisure
2.7%
Media
3.2%
Road & Rail
3.3%
Gas Utilities
3.3%
Banks
3.7%
Chemicals
3.9%
Money Market Funds
4.1%
Health Care Providers & Services
4.1%
Trading Companies & Distributors
4.2%
Specialty Retail
4.4%
Building Products
4.4%
Electrical Equipment
4.5%
Software
5.5%
Machinery
6.8%
Diversified Consumer Services
7.9%
Real Estate Management & Development
8.6%
Insurance
12.6%
Professional Services
13.0%
Largest Holdings [Text Block]

Top 10 Holdings (% of net assets)

Table Summary
Holding Name
% of Net Assets
CBIZ, Inc.
5.6%
Baldwin Insurance Group, Inc. (The)
5.3%
Frontdoor, Inc.
4.7%
Colliers International Group, Inc.
4.6%
Novanta, Inc.
4.5%
Floor & Decor Holdings, Inc. - Class A
4.4%
Casella Waste Systems, Inc. - Class A
4.3%
SiteOne Landscape Supply, Inc.
4.2%
Trisura Group Ltd.
4.1%
Chemed Corporation
4.1%
Material Fund Change [Text Block]

No material changes occurred during the period ended June 30, 2026.