v3.26.3
Shareholder Report, Holdings (Details)
Jul. 31, 2026
C000048022 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 15.20% [1],[2]
C000048022 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.90% [1],[2]
C000048022 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 17.40% [1],[2]
C000048022 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 18.20% [1],[2]
C000048022 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 34.10% [1],[2]
C000048022 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.20% [1],[2]
C000048022 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00% [2]
C000219780 [Member] | Supranational [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.30%
C000219780 [Member] | Other [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.30%
C000219780 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.70% [3]
C000219780 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.50% [3]
C000219780 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.60% [3]
C000219780 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 21.20% [3]
C000219780 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 30.70% [3]
C000219780 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 23.80% [3]
C000219780 [Member] | N A not applicable [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.50% [3]
C000219780 [Member] | CANADA  
Holdings [Line Items]  
Percent of Total Investments 3.50%
C000219780 [Member] | FRANCE  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000219780 [Member] | GERMANY  
Holdings [Line Items]  
Percent of Total Investments 1.70%
C000219780 [Member] | KOREA, REPUBLIC OF  
Holdings [Line Items]  
Percent of Total Investments 1.60%
C000219780 [Member] | MAURITIUS  
Holdings [Line Items]  
Percent of Total Investments 0.80%
C000219780 [Member] | NETHERLANDS  
Holdings [Line Items]  
Percent of Total Investments 5.30%
C000219780 [Member] | UNITED ARAB EMIRATES  
Holdings [Line Items]  
Percent of Total Investments 1.10%
C000219780 [Member] | UNITED KINGDOM  
Holdings [Line Items]  
Percent of Total Investments 1.60%
C000219780 [Member] | UNITED STATES  
Holdings [Line Items]  
Percent of Total Investments 67.00%
C000219780 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.60%
C000219780 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 51.50% [4]
C000219780 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.60%
C000219780 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.90%
C000219780 [Member] | Collateralized Mortgage-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 16.90%
C000219780 [Member] | Emerging Market Debt and Foreign Corporate Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.00%
C000219780 [Member] | Investments Purchased with Collateral from Securities Lending [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.50%
C000238439 [Member] | Other [Member]  
Holdings [Line Items]  
Percent of Total Investments 29.80%
C000238439 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 25.30% [5]
C000238439 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 22.90% [5]
C000238439 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 39.60% [5]
C000238439 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70% [5]
C000238439 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.60% [5]
C000238439 [Member] | N A not applicable [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.90% [5]
C000238439 [Member] | UNITED ARAB EMIRATES  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000238439 [Member] | TÜRKIYE  
Holdings [Line Items]  
Percent of Total Investments 3.10%
C000238439 [Member] | SOUTH AFRICA  
Holdings [Line Items]  
Percent of Total Investments 3.60%
C000238439 [Member] | SAUDI ARABIA  
Holdings [Line Items]  
Percent of Total Investments 7.20%
C000238439 [Member] | ROMANIA  
Holdings [Line Items]  
Percent of Total Investments 3.60%
C000238439 [Member] | POLAND  
Holdings [Line Items]  
Percent of Total Investments 4.40%
C000238439 [Member] | PERU  
Holdings [Line Items]  
Percent of Total Investments 3.90%
C000238439 [Member] | OMAN  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000238439 [Member] | NIGERIA  
Holdings [Line Items]  
Percent of Total Investments 2.70%
C000238439 [Member] | MEXICO  
Holdings [Line Items]  
Percent of Total Investments 11.80%
C000238439 [Member] | INDONESIA  
Holdings [Line Items]  
Percent of Total Investments 4.40%
C000238439 [Member] | INDIA  
Holdings [Line Items]  
Percent of Total Investments 3.00%
C000238439 [Member] | HUNGARY  
Holdings [Line Items]  
Percent of Total Investments 4.10%
C000238439 [Member] | CHILE  
Holdings [Line Items]  
Percent of Total Investments 9.80%
C000238439 [Member] | BRAZIL  
Holdings [Line Items]  
Percent of Total Investments 3.00%
C000238439 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 41.30% [6]
C000238439 [Member] | Investments Purchased with Collateral from Securities Lending [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.90%
C000238439 [Member] | Sovereign Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 57.80%
C000238440 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.00% [7]
C000238440 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 95.10% [7]
C000238440 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10% [7]
C000238440 [Member] | N A not applicable [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.80% [7]
C000238440 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 96.20% [8]
C000238440 [Member] | Investments Purchased with Collateral from Securities Lending [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000238440 [Member] | Exchange Traded Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.90%
C000238440 [Member] | Common Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000238441 [Member] | Other [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.70%
C000238441 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.30% [9]
C000238441 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 21.80% [9]
C000238441 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 67.60% [9]
C000238441 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.90% [9]
C000238441 [Member] | N A not applicable [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.40% [9]
C000238441 [Member] | CANADA  
Holdings [Line Items]  
Percent of Total Investments 10.70%
C000238441 [Member] | FINLAND  
Holdings [Line Items]  
Percent of Total Investments 1.10%
C000238441 [Member] | FRANCE  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000238441 [Member] | GERMANY  
Holdings [Line Items]  
Percent of Total Investments 1.10%
C000238441 [Member] | JAPAN  
Holdings [Line Items]  
Percent of Total Investments 1.10%
C000238441 [Member] | NETHERLANDS  
Holdings [Line Items]  
Percent of Total Investments 2.20%
C000238441 [Member] | UNITED KINGDOM  
Holdings [Line Items]  
Percent of Total Investments 13.30%
C000238441 [Member] | UNITED STATES  
Holdings [Line Items]  
Percent of Total Investments 52.70%
C000238441 [Member] | SPAIN  
Holdings [Line Items]  
Percent of Total Investments 4.60%
C000238441 [Member] | SWITZERLAND  
Holdings [Line Items]  
Percent of Total Investments 4.80%
C000238441 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 90.70% [10]
C000238441 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.90%
C000238441 [Member] | Investments Purchased with Collateral from Securities Lending [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.40%
C000238442 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80% [11]
C000238442 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.70% [11]
C000238442 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.60% [11]
C000238442 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.00% [11]
C000238442 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 54.40% [11]
C000238442 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 27.50% [11]
C000238442 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.40%
C000238442 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.90%
C000238442 [Member] | Collateralized Mortgage-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 84.70%
C000248080 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 57.50% [12]
C000248080 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 42.50% [12]
C000248080 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00% [12]
[1] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[2] Total investments include the Fund’s assets attributable to financial leverage. For these purposes, financial leverage includes the Fund’s investments in the residual interest certificates (also called inverse floating rate securities) in tender option bond (TOB) trusts, including the portion of assets held by a TOB trust that has been effectively financed by the trust’s issuance of floating rate securities.
[3] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[4] Includes 1.3% of $1,000 Par Preferred and/or Contingent Capital Securities.
[5] The Fund uses credit quality ratings for its portfolio securities provided by Moody’s, S&P and Fitch. If all three of Moody’s, S&P, and Fitch provide a rating for a security, the middle is used; if two of the three agencies rate a security, the lower rating is used; and if only one rating agency rates a security, that rating is used. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC/CC/C and D are below-investment grade ratings. Credit ratings are subject to change. Holdings designated N/R are not rated by Moody’s, S&P or Fitch.
[6] Includes 6.2% of $1,000 Par Preferred and/or Contingent Capital Securities.
[7] The ratings disclosed are the lowest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[8] Includes 0.7% of $1,000 Par Preferred and/or Contingent Capital Securities.
[9] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[10] Includes 89.4% of $1,000 Par Preferred and/or Contingent Capital Securities.
[11] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[12] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.