v3.26.1
Shareholder Report
 6 Months Ended
Apr. 30, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name MFS SERIES TRUST IX
Entity Central Index Key 0000063075
Entity Investment Company Type N-1A
Document Period End Date Apr. 30, 2026
C000006724 [Member]  
Shareholder Report [Line Items]  
Fund Name MFS® Inflation-AdjustedBond Fund
Class Name Class A
Trading Symbol MIAAX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about MFS Inflation-Adjusted Bond Fund for the period of November 1, 2025 to April 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to orderliterature@mfs.com.
Additional Information Phone Number 1‑800‑225‑2606
Additional Information Email orderliterature@mfs.com
Additional Information Website funds.mfs.com
Expenses [Text Block]
FUND EXPENSES
What were the fund costs for the last six months?
(based on a hypothetical $10,000 investment)
Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment (annualized)
A $33 0.66%
Expenses Paid, Amount $ 33
Expense Ratio, Percent 0.66%
Net Assets $ 1,511,260,673
Holdings Count | Holding 108
Investment Company Portfolio Turnover 10.00%
Additional Fund Statistics [Text Block]
FUND STATISTICS AS OF 4/30/26
Net Assets ($): 1,511,260,673 Average Effective Maturity (yrs): 7.2
Total Number of Holdings: 108 Average Effective Duration (yrs): 6.9
Portfolio Turnover Rate (%): 10
Where the fund holds derivatives, they are not included in the total number of portfolio holdings.
Holdings [Text Block]
PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 4/30/26)
Portfolio structure
Fixed Income 99.2%
Money Market Funds 0.8%
Composition including fixed income credit quality
AAA 2.3%
AA 1.2%
A 0.3%
U.S. Government 89.7%
Federal Agencies 5.7%
Money Market Funds 0.8%
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
Credit Ratings Selection [Text Block]
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
C000006728 [Member]  
Shareholder Report [Line Items]  
Fund Name MFS® Inflation-AdjustedBond Fund
Class Name Class I
Trading Symbol MIAIX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about MFS Inflation-Adjusted Bond Fund for the period of November 1, 2025 to April 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to orderliterature@mfs.com.
Additional Information Phone Number 1‑800‑225‑2606
Additional Information Email orderliterature@mfs.com
Additional Information Website funds.mfs.com
Expenses [Text Block]
FUND EXPENSES
What were the fund costs for the last six months?
(based on a hypothetical $10,000 investment)
Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment (annualized)
I $25 0.51%
Expenses Paid, Amount $ 25
Expense Ratio, Percent 0.51%
Net Assets $ 1,511,260,673
Holdings Count | Holding 108
Investment Company Portfolio Turnover 10.00%
Additional Fund Statistics [Text Block]
FUND STATISTICS AS OF 4/30/26
Net Assets ($): 1,511,260,673 Average Effective Maturity (yrs): 7.2
Total Number of Holdings: 108 Average Effective Duration (yrs): 6.9
Portfolio Turnover Rate (%): 10
Where the fund holds derivatives, they are not included in the total number of portfolio holdings.
Holdings [Text Block]
PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 4/30/26)
Portfolio structure
Fixed Income 99.2%
Money Market Funds 0.8%
Composition including fixed income credit quality
AAA 2.3%
AA 1.2%
A 0.3%
U.S. Government 89.7%
Federal Agencies 5.7%
Money Market Funds 0.8%
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
Credit Ratings Selection [Text Block]
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
C000006730 [Member]  
Shareholder Report [Line Items]  
Fund Name MFS® Inflation-AdjustedBond Fund
Class Name Class R1
Trading Symbol MIALX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about MFS Inflation-Adjusted Bond Fund for the period of November 1, 2025 to April 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to orderliterature@mfs.com.
Additional Information Phone Number 1‑800‑225‑2606
Additional Information Email orderliterature@mfs.com
Additional Information Website funds.mfs.com
Expenses [Text Block]
FUND EXPENSES
What were the fund costs for the last six months?
(based on a hypothetical $10,000 investment)
Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment (annualized)
R1 $75 1.51%
Expenses Paid, Amount $ 75
Expense Ratio, Percent 1.51%
Net Assets $ 1,511,260,673
Holdings Count | Holding 108
Investment Company Portfolio Turnover 10.00%
Additional Fund Statistics [Text Block]
FUND STATISTICS AS OF 4/30/26
Net Assets ($): 1,511,260,673 Average Effective Maturity (yrs): 7.2
Total Number of Holdings: 108 Average Effective Duration (yrs): 6.9
Portfolio Turnover Rate (%): 10
Where the fund holds derivatives, they are not included in the total number of portfolio holdings.
Holdings [Text Block]
PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 4/30/26)
Portfolio structure
Fixed Income 99.2%
Money Market Funds 0.8%
Composition including fixed income credit quality
AAA 2.3%
AA 1.2%
A 0.3%
U.S. Government 89.7%
Federal Agencies 5.7%
Money Market Funds 0.8%
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
Credit Ratings Selection [Text Block]
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
C000006727 [Member]  
Shareholder Report [Line Items]  
Fund Name MFS® Inflation-AdjustedBond Fund
Class Name Class C
Trading Symbol MIACX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about MFS Inflation-Adjusted Bond Fund for the period of November 1, 2025 to April 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to orderliterature@mfs.com.
Additional Information Phone Number 1‑800‑225‑2606
Additional Information Email orderliterature@mfs.com
Additional Information Website funds.mfs.com
Expenses [Text Block]
FUND EXPENSES
What were the fund costs for the last six months?
(based on a hypothetical $10,000 investment)
Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment (annualized)
C $75 1.51%
Expenses Paid, Amount $ 75
Expense Ratio, Percent 1.51%
Net Assets $ 1,511,260,673
Holdings Count | Holding 108
Investment Company Portfolio Turnover 10.00%
Additional Fund Statistics [Text Block]
FUND STATISTICS AS OF 4/30/26
Net Assets ($): 1,511,260,673 Average Effective Maturity (yrs): 7.2
Total Number of Holdings: 108 Average Effective Duration (yrs): 6.9
Portfolio Turnover Rate (%): 10
Where the fund holds derivatives, they are not included in the total number of portfolio holdings.
Holdings [Text Block]
PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 4/30/26)
Portfolio structure
Fixed Income 99.2%
Money Market Funds 0.8%
Composition including fixed income credit quality
AAA 2.3%
AA 1.2%
A 0.3%
U.S. Government 89.7%
Federal Agencies 5.7%
Money Market Funds 0.8%
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
Credit Ratings Selection [Text Block]
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
C000006726 [Member]  
Shareholder Report [Line Items]  
Fund Name MFS® Inflation-AdjustedBond Fund
Class Name Class B
Trading Symbol MIABX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about MFS Inflation-Adjusted Bond Fund for the period of November 1, 2025 to April 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to orderliterature@mfs.com.
Additional Information Phone Number 1‑800‑225‑2606
Additional Information Email orderliterature@mfs.com
Additional Information Website funds.mfs.com
Expenses [Text Block]
FUND EXPENSES
What were the fund costs for the last six months?
(based on a hypothetical $10,000 investment)
Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment (annualized)
B $70 1.40%
Expenses Paid, Amount $ 70
Expense Ratio, Percent 1.40%
Net Assets $ 1,511,260,673
Holdings Count | Holding 108
Investment Company Portfolio Turnover 10.00%
Additional Fund Statistics [Text Block]
FUND STATISTICS AS OF 4/30/26
Net Assets ($): 1,511,260,673 Average Effective Maturity (yrs): 7.2
Total Number of Holdings: 108 Average Effective Duration (yrs): 6.9
Portfolio Turnover Rate (%): 10
Where the fund holds derivatives, they are not included in the total number of portfolio holdings.
Holdings [Text Block]
PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 4/30/26)
Portfolio structure
Fixed Income 99.2%
Money Market Funds 0.8%
Composition including fixed income credit quality
AAA 2.3%
AA 1.2%
A 0.3%
U.S. Government 89.7%
Federal Agencies 5.7%
Money Market Funds 0.8%
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
Credit Ratings Selection [Text Block]
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
C000006732 [Member]  
Shareholder Report [Line Items]  
Fund Name MFS® Inflation-AdjustedBond Fund
Class Name Class R2
Trading Symbol MIATX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about MFS Inflation-Adjusted Bond Fund for the period of November 1, 2025 to April 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to orderliterature@mfs.com.
Additional Information Phone Number 1‑800‑225‑2606
Additional Information Email orderliterature@mfs.com
Additional Information Website funds.mfs.com
Expenses [Text Block]
FUND EXPENSES
What were the fund costs for the last six months?
(based on a hypothetical $10,000 investment)
Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment (annualized)
R2 $50 1.01%
Expenses Paid, Amount $ 50
Expense Ratio, Percent 1.01%
Net Assets $ 1,511,260,673
Holdings Count | Holding 108
Investment Company Portfolio Turnover 10.00%
Additional Fund Statistics [Text Block]
FUND STATISTICS AS OF 4/30/26
Net Assets ($): 1,511,260,673 Average Effective Maturity (yrs): 7.2
Total Number of Holdings: 108 Average Effective Duration (yrs): 6.9
Portfolio Turnover Rate (%): 10
Where the fund holds derivatives, they are not included in the total number of portfolio holdings.
Holdings [Text Block]
PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 4/30/26)
Portfolio structure
Fixed Income 99.2%
Money Market Funds 0.8%
Composition including fixed income credit quality
AAA 2.3%
AA 1.2%
A 0.3%
U.S. Government 89.7%
Federal Agencies 5.7%
Money Market Funds 0.8%
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
Credit Ratings Selection [Text Block]
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
C000006733 [Member]  
Shareholder Report [Line Items]  
Fund Name MFS® Inflation-AdjustedBond Fund
Class Name Class R3
Trading Symbol MIAHX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about MFS Inflation-Adjusted Bond Fund for the period of November 1, 2025 to April 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to orderliterature@mfs.com.
Additional Information Phone Number 1‑800‑225‑2606
Additional Information Email orderliterature@mfs.com
Additional Information Website funds.mfs.com
Expenses [Text Block]
FUND EXPENSES
What were the fund costs for the last six months?
(based on a hypothetical $10,000 investment)
Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment (annualized)
R3 $38 0.76%
Expenses Paid, Amount $ 38
Expense Ratio, Percent 0.76%
Net Assets $ 1,511,260,673
Holdings Count | Holding 108
Investment Company Portfolio Turnover 10.00%
Additional Fund Statistics [Text Block]
FUND STATISTICS AS OF 4/30/26
Net Assets ($): 1,511,260,673 Average Effective Maturity (yrs): 7.2
Total Number of Holdings: 108 Average Effective Duration (yrs): 6.9
Portfolio Turnover Rate (%): 10
Where the fund holds derivatives, they are not included in the total number of portfolio holdings.
Holdings [Text Block]
PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 4/30/26)
Portfolio structure
Fixed Income 99.2%
Money Market Funds 0.8%
Composition including fixed income credit quality
AAA 2.3%
AA 1.2%
A 0.3%
U.S. Government 89.7%
Federal Agencies 5.7%
Money Market Funds 0.8%
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
Credit Ratings Selection [Text Block]
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
C000006725 [Member]  
Shareholder Report [Line Items]  
Fund Name MFS® Inflation-AdjustedBond Fund
Class Name Class R4
Trading Symbol MIAJX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about MFS Inflation-Adjusted Bond Fund for the period of November 1, 2025 to April 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to orderliterature@mfs.com.
Additional Information Phone Number 1‑800‑225‑2606
Additional Information Email orderliterature@mfs.com
Additional Information Website funds.mfs.com
Expenses [Text Block]
FUND EXPENSES
What were the fund costs for the last six months?
(based on a hypothetical $10,000 investment)
Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment (annualized)
R4 $25 0.51%
Expenses Paid, Amount $ 25
Expense Ratio, Percent 0.51%
Net Assets $ 1,511,260,673
Holdings Count | Holding 108
Investment Company Portfolio Turnover 10.00%
Additional Fund Statistics [Text Block]
FUND STATISTICS AS OF 4/30/26
Net Assets ($): 1,511,260,673 Average Effective Maturity (yrs): 7.2
Total Number of Holdings: 108 Average Effective Duration (yrs): 6.9
Portfolio Turnover Rate (%): 10
Where the fund holds derivatives, they are not included in the total number of portfolio holdings.
Holdings [Text Block]
PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 4/30/26)
Portfolio structure
Fixed Income 99.2%
Money Market Funds 0.8%
Composition including fixed income credit quality
AAA 2.3%
AA 1.2%
A 0.3%
U.S. Government 89.7%
Federal Agencies 5.7%
Money Market Funds 0.8%
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
Credit Ratings Selection [Text Block]
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
C000126364 [Member]  
Shareholder Report [Line Items]  
Fund Name MFS® Inflation-AdjustedBond Fund
Class Name Class R6
Trading Symbol MIAKX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about MFS Inflation-Adjusted Bond Fund for the period of November 1, 2025 to April 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to orderliterature@mfs.com.
Additional Information Phone Number 1‑800‑225‑2606
Additional Information Email orderliterature@mfs.com
Additional Information Website funds.mfs.com
Expenses [Text Block]
FUND EXPENSES
What were the fund costs for the last six months?
(based on a hypothetical $10,000 investment)
Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment (annualized)
R6 $20 0.41%
Expenses Paid, Amount $ 20
Expense Ratio, Percent 0.41%
Net Assets $ 1,511,260,673
Holdings Count | Holding 108
Investment Company Portfolio Turnover 10.00%
Additional Fund Statistics [Text Block]
FUND STATISTICS AS OF 4/30/26
Net Assets ($): 1,511,260,673 Average Effective Maturity (yrs): 7.2
Total Number of Holdings: 108 Average Effective Duration (yrs): 6.9
Portfolio Turnover Rate (%): 10
Where the fund holds derivatives, they are not included in the total number of portfolio holdings.
Holdings [Text Block]
PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 4/30/26)
Portfolio structure
Fixed Income 99.2%
Money Market Funds 0.8%
Composition including fixed income credit quality
AAA 2.3%
AA 1.2%
A 0.3%
U.S. Government 89.7%
Federal Agencies 5.7%
Money Market Funds 0.8%
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.
Credit Ratings Selection [Text Block]
Ratings are assigned using Moody’s, Fitch, and Standard & Poor’s and applying a hierarchy: If all 3 agencies rate a security, the middle rating is assigned; if 2 agencies rate a security, the lower rating is assigned. If none of the 3 agencies rate a security, we use DBRS Morningstar. If none of the 4 agencies rate a security, we use Kroll Bond Rating Agency. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change.