v3.25.2
Shareholder Report
6 Months Ended
Apr. 30, 2025
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name First Trust Series Fund
Entity Central Index Key 0001497778
Entity Investment Company Type N-1A
Document Period End Date Apr. 30, 2025
C000092932 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Preferred Securitiesand Income Fund
Class Name Class A
Trading Symbol FPEAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Preferred Securities and Income Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FPEAX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FPEAX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Preferred Securities and Income Fund - Class A $69 1.40%(1)
(1)
Annualized.
Expenses Paid, Amount $ 69
Expense Ratio, Percent 1.40% [1]
Net Assets $ 201,492,012
Holdings Count | Holding 209
Investment Company Portfolio Turnover 25.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $201,492,012
Total number of portfolio holdings 209
Portfolio turnover rate 25%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
Sector Allocation
Graphical Representation - Allocation 2 Chart
Largest Holdings [Text Block]
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
C000092933 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Preferred Securitiesand Income Fund
Class Name Class C
Trading Symbol FPECX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Preferred Securities and Income Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FPECX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FPECX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Preferred Securities and Income Fund - Class C $106 2.15%(1)
(1)
Annualized.
Expenses Paid, Amount $ 106
Expense Ratio, Percent 2.15% [2]
Net Assets $ 201,492,012
Holdings Count | Holding 209
Investment Company Portfolio Turnover 25.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $201,492,012
Total number of portfolio holdings 209
Portfolio turnover rate 25%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
Sector Allocation
Graphical Representation - Allocation 2 Chart
Largest Holdings [Text Block]
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
C000092934 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Preferred Securitiesand Income Fund
Class Name Class F
Trading Symbol FPEFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Preferred Securities and Income Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FPEFX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FPEFX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Preferred Securities and Income Fund - Class F $64 1.30%(1)
(1)
Annualized.
Expenses Paid, Amount $ 64
Expense Ratio, Percent 1.30% [3]
Net Assets $ 201,492,012
Holdings Count | Holding 209
Investment Company Portfolio Turnover 25.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $201,492,012
Total number of portfolio holdings 209
Portfolio turnover rate 25%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
Sector Allocation
Graphical Representation - Allocation 2 Chart
Largest Holdings [Text Block]
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
C000092935 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Preferred Securitiesand Income Fund
Class Name Class I
Trading Symbol FPEIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Preferred Securities and Income Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FPEIX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FPEIX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Preferred Securities and Income Fund - Class I $53 1.08%(1)
(1)
Annualized.
Expenses Paid, Amount $ 53
Expense Ratio, Percent 1.08% [4]
Net Assets $ 201,492,012
Holdings Count | Holding 209
Investment Company Portfolio Turnover 25.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $201,492,012
Total number of portfolio holdings 209
Portfolio turnover rate 25%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
Sector Allocation
Graphical Representation - Allocation 2 Chart
Largest Holdings [Text Block]
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
C000092936 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Preferred Securitiesand Income Fund
Class Name Class R3
Trading Symbol FPERX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Preferred Securities and Income Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FPERX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FPERX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Preferred Securities and Income Fund - Class R3 $82 1.65%(1)
(1)
Annualized.
Expenses Paid, Amount $ 82
Expense Ratio, Percent 1.65% [5]
Net Assets $ 201,492,012
Holdings Count | Holding 209
Investment Company Portfolio Turnover 25.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $201,492,012
Total number of portfolio holdings 209
Portfolio turnover rate 25%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
Sector Allocation
Graphical Representation - Allocation 2 Chart
Largest Holdings [Text Block]
Top Ten Holdings
Bank of America Corp., 6.63% 2.5%
Wells Fargo & Co., Series L, 7.50% 2.3%
Barclays PLC, 8.00% 2.1%
JPMorgan Chase & Co., Series NN, 6.88% 1.7%
Credit Agricole S.A., 6.70% 1.5%
Land O'Lakes, Inc., 8.00% 1.4%
BNP Paribas S.A., 8.50% 1.4%
Hartford Financial Services Group (The), Inc., 6.71%, 02/12/47 1.3%
Charles Schwab (The) Corp., Series H, 4.00% 1.3%
Lloyds Banking Group PLC, 8.00% 1.3%
C000092938 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust/Confluence Small Cap Value Fund
Class Name Class A
Trading Symbol FOVAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust/Confluence Small Cap Value Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FOVAX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FOVAX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust/Confluence Small Cap Value Fund - Class A $75 1.60%(1)
(1)
Annualized.
Expenses Paid, Amount $ 75
Expense Ratio, Percent 1.60% [6]
Net Assets $ 17,766,167
Holdings Count | Holding 33
Investment Company Portfolio Turnover 13.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $17,766,167
Total number of portfolio holdings 33
Portfolio turnover rate 13%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Top Ten Holdings
SJW Group 3.9%
Baldwin Insurance (The) Group, Inc. 3.9%
JBT Marel Corp. 3.8%
Hagerty, Inc., Class A 3.8%
I3 Verticals, Inc., Class A 3.8%
Altus Group Ltd. 3.6%
Sapiens International Corp., N.V. 3.5%
Cavco Industries, Inc. 3.5%
TripAdvisor, Inc. 3.5%
J&J Snack Foods Corp. 3.5%
Sector Allocation
Graphical Representation - Allocation 2 Chart
Largest Holdings [Text Block]
Top Ten Holdings
SJW Group 3.9%
Baldwin Insurance (The) Group, Inc. 3.9%
JBT Marel Corp. 3.8%
Hagerty, Inc., Class A 3.8%
I3 Verticals, Inc., Class A 3.8%
Altus Group Ltd. 3.6%
Sapiens International Corp., N.V. 3.5%
Cavco Industries, Inc. 3.5%
TripAdvisor, Inc. 3.5%
J&J Snack Foods Corp. 3.5%
C000092939 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust/Confluence Small Cap Value Fund
Class Name Class C
Trading Symbol FOVCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust/Confluence Small Cap Value Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FOVCX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FOVCX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust/Confluence Small Cap Value Fund - Class C $110 2.35%(1)
(1)
Annualized.
Expenses Paid, Amount $ 110
Expense Ratio, Percent 2.35% [7]
Net Assets $ 17,766,167
Holdings Count | Holding 33
Investment Company Portfolio Turnover 13.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $17,766,167
Total number of portfolio holdings 33
Portfolio turnover rate 13%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Top Ten Holdings
SJW Group 3.9%
Baldwin Insurance (The) Group, Inc. 3.9%
JBT Marel Corp. 3.8%
Hagerty, Inc., Class A 3.8%
I3 Verticals, Inc., Class A 3.8%
Altus Group Ltd. 3.6%
Sapiens International Corp., N.V. 3.5%
Cavco Industries, Inc. 3.5%
TripAdvisor, Inc. 3.5%
J&J Snack Foods Corp. 3.5%
Sector Allocation
Graphical Representation - Allocation 2 Chart
Largest Holdings [Text Block]
Top Ten Holdings
SJW Group 3.9%
Baldwin Insurance (The) Group, Inc. 3.9%
JBT Marel Corp. 3.8%
Hagerty, Inc., Class A 3.8%
I3 Verticals, Inc., Class A 3.8%
Altus Group Ltd. 3.6%
Sapiens International Corp., N.V. 3.5%
Cavco Industries, Inc. 3.5%
TripAdvisor, Inc. 3.5%
J&J Snack Foods Corp. 3.5%
C000092941 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust/Confluence Small Cap Value Fund
Class Name Class I
Trading Symbol FOVIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust/Confluence Small Cap Value Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FOVIX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FOVIX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust/Confluence Small Cap Value Fund - Class I $63 1.35%(1)
(1)
Annualized.
Expenses Paid, Amount $ 63
Expense Ratio, Percent 1.35% [8]
Net Assets $ 17,766,167
Holdings Count | Holding 33
Investment Company Portfolio Turnover 13.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $17,766,167
Total number of portfolio holdings 33
Portfolio turnover rate 13%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Top Ten Holdings
SJW Group 3.9%
Baldwin Insurance (The) Group, Inc. 3.9%
JBT Marel Corp. 3.8%
Hagerty, Inc., Class A 3.8%
I3 Verticals, Inc., Class A 3.8%
Altus Group Ltd. 3.6%
Sapiens International Corp., N.V. 3.5%
Cavco Industries, Inc. 3.5%
TripAdvisor, Inc. 3.5%
J&J Snack Foods Corp. 3.5%
Sector Allocation
Graphical Representation - Allocation 2 Chart
Largest Holdings [Text Block]
Top Ten Holdings
SJW Group 3.9%
Baldwin Insurance (The) Group, Inc. 3.9%
JBT Marel Corp. 3.8%
Hagerty, Inc., Class A 3.8%
I3 Verticals, Inc., Class A 3.8%
Altus Group Ltd. 3.6%
Sapiens International Corp., N.V. 3.5%
Cavco Industries, Inc. 3.5%
TripAdvisor, Inc. 3.5%
J&J Snack Foods Corp. 3.5%
C000118178 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Short Duration High Income Fund
Class Name Class A
Trading Symbol FDHAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Short Duration High Income Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FDHAX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FDHAX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Short Duration High Income Fund - Class A $63 1.25%(1)
(1)
Annualized.
Expenses Paid, Amount $ 63
Expense Ratio, Percent 1.25% [9]
Net Assets $ 68,352,076
Holdings Count | Holding 222
Investment Company Portfolio Turnover 45.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $68,352,076
Total number of portfolio holdings 222
Portfolio turnover rate 45%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of net assets and total investments, respectively, of the Fund.
Fund Allocation
Corporate Bonds and Notes 47.4%
Senior Floating-Rate Loan Interests 35.4%
Foreign Corporate Bonds and Notes 9.1%
Money Market Funds 8.5%
Common Stocks 0.0%
Rights 0.0%
Net Other Assets and Liabilities (0.4)%
Credit Quality(2)
Graphical Representation - Allocation 2 Chart
Any amount shown as 0.0% represents less than 0.1%.
(2) The ratings are by S&P Global Ratings. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated. Ratings are measured on a scale that generally ranges from AAA (highest) to D (lowest). Investment grade is defined as those issuers that have a long-term credit rating of BBB- or higher. "NR" indicates no rating. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Quality Explanation [Text Block] The ratings are by S&P Global Ratings. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated. Ratings are measured on a scale that generally ranges from AAA (highest) to D (lowest). Investment grade is defined as those issuers that have a long-term credit rating of BBB- or higher. "NR" indicates no rating. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Ratings Selection [Text Block] The ratings are by S&P Global Ratings. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated.
C000121471 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Short Duration High Income Fund
Class Name Class C
Trading Symbol FDHCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Short Duration High Income Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FDHCX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FDHCX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Short Duration High Income Fund - Class C $100 2.00%(1)
(1)
Annualized.
Expenses Paid, Amount $ 100
Expense Ratio, Percent 2.00% [10]
Net Assets $ 68,352,076
Holdings Count | Holding 222
Investment Company Portfolio Turnover 45.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $68,352,076
Total number of portfolio holdings 222
Portfolio turnover rate 45%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of net assets and total investments, respectively, of the Fund.
Fund Allocation
Corporate Bonds and Notes 47.4%
Senior Floating-Rate Loan Interests 35.4%
Foreign Corporate Bonds and Notes 9.1%
Money Market Funds 8.5%
Common Stocks 0.0%
Rights 0.0%
Net Other Assets and Liabilities (0.4)%
Credit Quality(2)
Graphical Representation - Allocation 2 Chart
Any amount shown as 0.0% represents less than 0.1%.
(2) The ratings are by S&P Global Ratings. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated. Ratings are measured on a scale that generally ranges from AAA (highest) to D (lowest). Investment grade is defined as those issuers that have a long-term credit rating of BBB- or higher. "NR" indicates no rating. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Quality Explanation [Text Block] The ratings are by S&P Global Ratings. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated. Ratings are measured on a scale that generally ranges from AAA (highest) to D (lowest). Investment grade is defined as those issuers that have a long-term credit rating of BBB- or higher. "NR" indicates no rating. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Ratings Selection [Text Block] The ratings are by S&P Global Ratings. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated.
C000121472 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Short Duration High Income Fund
Class Name Class I
Trading Symbol FDHIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Short Duration High Income Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/FDHIX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/FDHIX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Short Duration High Income Fund - Class I $50 1.00%(1)
(1)
Annualized.
Expenses Paid, Amount $ 50
Expense Ratio, Percent 1.00% [11]
Net Assets $ 68,352,076
Holdings Count | Holding 222
Investment Company Portfolio Turnover 45.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $68,352,076
Total number of portfolio holdings 222
Portfolio turnover rate 45%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of net assets and total investments, respectively, of the Fund.
Fund Allocation
Corporate Bonds and Notes 47.4%
Senior Floating-Rate Loan Interests 35.4%
Foreign Corporate Bonds and Notes 9.1%
Money Market Funds 8.5%
Common Stocks 0.0%
Rights 0.0%
Net Other Assets and Liabilities (0.4)%
Credit Quality(2)
Graphical Representation - Allocation 2 Chart
Any amount shown as 0.0% represents less than 0.1%.
(2) The ratings are by S&P Global Ratings. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated. Ratings are measured on a scale that generally ranges from AAA (highest) to D (lowest). Investment grade is defined as those issuers that have a long-term credit rating of BBB- or higher. "NR" indicates no rating. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Quality Explanation [Text Block] The ratings are by S&P Global Ratings. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated. Ratings are measured on a scale that generally ranges from AAA (highest) to D (lowest). Investment grade is defined as those issuers that have a long-term credit rating of BBB- or higher. "NR" indicates no rating. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Ratings Selection [Text Block] The ratings are by S&P Global Ratings. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated.
C000232962 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Managed Municipal Fund
Class Name Class A
Trading Symbol CWAAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Managed Municipal Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/CWAAX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/CWAAX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Managed Municipal Fund - Class A $14(1) 0.90%(2)
(1)
Class A Shares commenced investment operations on March 4, 2025. Had the class been in operation for a complete six months, the cost of a $10,000 investment would have been higher.
(2)
Annualized.
Expenses Paid, Amount $ 14 [12]
Expense Ratio, Percent 0.90% [13]
Net Assets $ 70,078,815
Holdings Count | Holding 134
Investment Company Portfolio Turnover 15.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $70,078,815
Total number of portfolio holdings 134
Portfolio turnover rate 15%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Credit Quality(1)
AAA 4.6
AA 35.5
A 32.8
BBB 12.5
BB 3.0
Not Rated 11.6
Sector Allocation
Graphical Representation - Allocation 2 Chart
(1) The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the highest rating is used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Quality Explanation [Text Block] The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the highest rating is used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Ratings Selection [Text Block] The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings or a comparably rated NRSRO.
C000232961 [Member]  
Shareholder Report [Line Items]  
Fund Name First Trust Managed Municipal Fund
Class Name Class I
Trading Symbol CWAIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the First Trust Managed Municipal Fund (the “Fund”) for the period of November 1, 2024 to April 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.ftportfolios.com/fund-documents/MF/CWAIX.  You can also request this information by contacting us at 1-800-621-1675 or info@ftportfolios.com.
Additional Information Phone Number 1-800-621-1675
Additional Information Email info@ftportfolios.com
Additional Information Website www.ftportfolios.com/fund-documents/MF/CWAIX
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?
(Based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
First Trust Managed Municipal Fund - Class I $32 0.65%(1)
(1)
Annualized.
Expenses Paid, Amount $ 32
Expense Ratio, Percent 0.65% [14]
Net Assets $ 70,078,815
Holdings Count | Holding 134
Investment Company Portfolio Turnover 15.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (As of April 30, 2025)
Fund net assets $70,078,815
Total number of portfolio holdings 134
Portfolio turnover rate 15%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (As of April 30, 2025)
The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund.
Top Ten Holdings
AAA 4.6
AA 35.5
A 32.8
BBB 12.5
BB 3.0
Not Rated 11.6
Sector Allocation
Graphical Representation - Allocation 2 Chart
(1) The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the highest rating is used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Quality Explanation [Text Block] The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the highest rating is used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. Credit ratings are subject to change.
Credit Ratings Selection [Text Block] The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings or a comparably rated NRSRO.
[1] Annualized.
[2] Annualized.
[3] Annualized.
[4] Annualized.
[5] Annualized.
[6] Annualized.
[7] Annualized.
[8] Annualized.
[9] Annualized.
[10] Annualized.
[11] Annualized.
[12] Class A Shares commenced investment operations on March 4, 2025. Had the class been in operation for a complete six months, the cost of a $10,000 investment would have been higher.
[13] Annualized.
[14] Annualized.