Shareholder Report, Holdings (Details)
|
Jan. 31, 2026 |
| C000116932 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000116932 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.00%
|
|
| C000116932 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.40%
|
|
| C000116932 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.40%
|
|
| C000116932 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000116932 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000116932 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000116932 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000116932 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.00%
|
[1] |
| C000116932 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000116932 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006472 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000006472 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.00%
|
|
| C000006472 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.40%
|
|
| C000006472 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.40%
|
|
| C000006472 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006472 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006472 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006472 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006472 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.00%
|
[2] |
| C000006472 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006472 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006483 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000006483 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.00%
|
|
| C000006483 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.40%
|
|
| C000006483 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.40%
|
|
| C000006483 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006483 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006483 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006483 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006483 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.00%
|
[3] |
| C000006483 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006483 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006482 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000006482 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.00%
|
|
| C000006482 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.40%
|
|
| C000006482 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.40%
|
|
| C000006482 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006482 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006482 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006482 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006482 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.00%
|
[4] |
| C000006482 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006482 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006480 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000006480 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.00%
|
|
| C000006480 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.40%
|
|
| C000006480 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.40%
|
|
| C000006480 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006480 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006480 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006480 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006480 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.00%
|
[5] |
| C000006480 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006480 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006478 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000006478 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.00%
|
|
| C000006478 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.40%
|
|
| C000006478 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.40%
|
|
| C000006478 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006478 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006478 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006478 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006478 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.00%
|
[6] |
| C000006478 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006478 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006477 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000006477 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.00%
|
|
| C000006477 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.40%
|
|
| C000006477 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.40%
|
|
| C000006477 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006477 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006477 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006477 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006477 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.00%
|
[7] |
| C000006477 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006477 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006476 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000006476 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.00%
|
|
| C000006476 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.40%
|
|
| C000006476 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.40%
|
|
| C000006476 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006476 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006476 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006476 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006476 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.00%
|
[8] |
| C000006476 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006476 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006471 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000006471 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.00%
|
|
| C000006471 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.40%
|
|
| C000006471 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.40%
|
|
| C000006471 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006471 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006471 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006471 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006471 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.00%
|
[9] |
| C000006471 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006471 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.00%
|
|
| C000006484 [Member] | Other Countries [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
20.10%
|
|
| C000006484 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.50%
|
|
| C000006484 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
9.20%
|
|
| C000006484 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.80%
|
|
| C000006484 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.80%
|
|
| C000006484 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006484 [Member] | Fitch, D Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006484 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006484 [Member] | Moody's, C Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006484 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000006484 [Member] | BRAZIL |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.00%
|
|
| C000006484 [Member] | CANADA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006484 [Member] | FRANCE |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.30%
|
|
| C000006484 [Member] | INDIA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006484 [Member] | ITALY |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000006484 [Member] | LUXEMBOURG |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.80%
|
|
| C000006484 [Member] | MEXICO |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.90%
|
|
| C000006484 [Member] | UNITED KINGDOM |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.00%
|
|
| C000006484 [Member] | UNITED STATES |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
59.00%
|
|
| C000006484 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006484 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
95.80%
|
[10] |
| C000006484 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006484 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006485 [Member] | Other Countries [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
20.10%
|
|
| C000006485 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.50%
|
|
| C000006485 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
9.20%
|
|
| C000006485 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.80%
|
|
| C000006485 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.80%
|
|
| C000006485 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006485 [Member] | Fitch, D Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006485 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006485 [Member] | Moody's, C Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006485 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000006485 [Member] | BRAZIL |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.00%
|
|
| C000006485 [Member] | CANADA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006485 [Member] | FRANCE |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.30%
|
|
| C000006485 [Member] | INDIA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006485 [Member] | ITALY |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000006485 [Member] | LUXEMBOURG |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.80%
|
|
| C000006485 [Member] | MEXICO |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.90%
|
|
| C000006485 [Member] | UNITED KINGDOM |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.00%
|
|
| C000006485 [Member] | UNITED STATES |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
59.00%
|
|
| C000006485 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006485 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
95.80%
|
[11] |
| C000006485 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006485 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006486 [Member] | Other Countries [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
20.10%
|
|
| C000006486 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.50%
|
|
| C000006486 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
9.20%
|
|
| C000006486 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.80%
|
|
| C000006486 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.80%
|
|
| C000006486 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006486 [Member] | Fitch, D Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006486 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006486 [Member] | Moody's, C Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006486 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000006486 [Member] | BRAZIL |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.00%
|
|
| C000006486 [Member] | CANADA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006486 [Member] | FRANCE |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.30%
|
|
| C000006486 [Member] | INDIA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006486 [Member] | ITALY |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000006486 [Member] | LUXEMBOURG |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.80%
|
|
| C000006486 [Member] | MEXICO |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.90%
|
|
| C000006486 [Member] | UNITED KINGDOM |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.00%
|
|
| C000006486 [Member] | UNITED STATES |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
59.00%
|
|
| C000006486 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006486 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
95.80%
|
[12] |
| C000006486 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006486 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006487 [Member] | Other Countries [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
20.10%
|
|
| C000006487 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.50%
|
|
| C000006487 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
9.20%
|
|
| C000006487 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.80%
|
|
| C000006487 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.80%
|
|
| C000006487 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000006487 [Member] | Fitch, D Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006487 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006487 [Member] | Moody's, C Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006487 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000006487 [Member] | BRAZIL |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.00%
|
|
| C000006487 [Member] | CANADA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000006487 [Member] | FRANCE |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.30%
|
|
| C000006487 [Member] | INDIA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000006487 [Member] | ITALY |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000006487 [Member] | LUXEMBOURG |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.80%
|
|
| C000006487 [Member] | MEXICO |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.90%
|
|
| C000006487 [Member] | UNITED KINGDOM |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.00%
|
|
| C000006487 [Member] | UNITED STATES |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
59.00%
|
|
| C000006487 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006487 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
95.80%
|
[13] |
| C000006487 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000006487 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064677 [Member] | Other Countries [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
20.10%
|
|
| C000064677 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.50%
|
|
| C000064677 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
9.20%
|
|
| C000064677 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.80%
|
|
| C000064677 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.80%
|
|
| C000064677 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000064677 [Member] | Fitch, D Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064677 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064677 [Member] | Moody's, C Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000064677 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000064677 [Member] | BRAZIL |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.00%
|
|
| C000064677 [Member] | CANADA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064677 [Member] | FRANCE |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.30%
|
|
| C000064677 [Member] | INDIA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000064677 [Member] | ITALY |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000064677 [Member] | LUXEMBOURG |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.80%
|
|
| C000064677 [Member] | MEXICO |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.90%
|
|
| C000064677 [Member] | UNITED KINGDOM |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.00%
|
|
| C000064677 [Member] | UNITED STATES |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
59.00%
|
|
| C000064677 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064677 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
95.80%
|
[14] |
| C000064677 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064677 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064678 [Member] | Other Countries [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
20.10%
|
|
| C000064678 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.50%
|
|
| C000064678 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
9.20%
|
|
| C000064678 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.80%
|
|
| C000064678 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.80%
|
|
| C000064678 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000064678 [Member] | Fitch, D Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064678 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064678 [Member] | Moody's, C Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000064678 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000064678 [Member] | BRAZIL |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.00%
|
|
| C000064678 [Member] | CANADA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064678 [Member] | FRANCE |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.30%
|
|
| C000064678 [Member] | INDIA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000064678 [Member] | ITALY |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000064678 [Member] | LUXEMBOURG |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.80%
|
|
| C000064678 [Member] | MEXICO |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.90%
|
|
| C000064678 [Member] | UNITED KINGDOM |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.00%
|
|
| C000064678 [Member] | UNITED STATES |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
59.00%
|
|
| C000064678 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064678 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
95.80%
|
[15] |
| C000064678 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064678 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064679 [Member] | Other Countries [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
20.10%
|
|
| C000064679 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.50%
|
|
| C000064679 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
9.20%
|
|
| C000064679 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.80%
|
|
| C000064679 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.80%
|
|
| C000064679 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000064679 [Member] | Fitch, D Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064679 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064679 [Member] | Moody's, C Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000064679 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000064679 [Member] | BRAZIL |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.00%
|
|
| C000064679 [Member] | CANADA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064679 [Member] | FRANCE |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.30%
|
|
| C000064679 [Member] | INDIA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000064679 [Member] | ITALY |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000064679 [Member] | LUXEMBOURG |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.80%
|
|
| C000064679 [Member] | MEXICO |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.90%
|
|
| C000064679 [Member] | UNITED KINGDOM |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.00%
|
|
| C000064679 [Member] | UNITED STATES |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
59.00%
|
|
| C000064679 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064679 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
95.80%
|
[16] |
| C000064679 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064679 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064680 [Member] | Other Countries [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
20.10%
|
|
| C000064680 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.50%
|
|
| C000064680 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
9.20%
|
|
| C000064680 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.80%
|
|
| C000064680 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.80%
|
|
| C000064680 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000064680 [Member] | Fitch, D Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064680 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064680 [Member] | Moody's, C Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000064680 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000064680 [Member] | BRAZIL |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.00%
|
|
| C000064680 [Member] | CANADA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064680 [Member] | FRANCE |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.30%
|
|
| C000064680 [Member] | INDIA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000064680 [Member] | ITALY |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000064680 [Member] | LUXEMBOURG |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.80%
|
|
| C000064680 [Member] | MEXICO |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.90%
|
|
| C000064680 [Member] | UNITED KINGDOM |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.00%
|
|
| C000064680 [Member] | UNITED STATES |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
59.00%
|
|
| C000064680 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064680 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
95.80%
|
[17] |
| C000064680 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064680 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064681 [Member] | Other Countries [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
20.10%
|
|
| C000064681 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.50%
|
|
| C000064681 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
9.20%
|
|
| C000064681 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
38.80%
|
|
| C000064681 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.80%
|
|
| C000064681 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000064681 [Member] | Fitch, D Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064681 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064681 [Member] | Moody's, C Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000064681 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000064681 [Member] | BRAZIL |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.00%
|
|
| C000064681 [Member] | CANADA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000064681 [Member] | FRANCE |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.30%
|
|
| C000064681 [Member] | INDIA |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000064681 [Member] | ITALY |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000064681 [Member] | LUXEMBOURG |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.80%
|
|
| C000064681 [Member] | MEXICO |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.90%
|
|
| C000064681 [Member] | UNITED KINGDOM |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.00%
|
|
| C000064681 [Member] | UNITED STATES |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
59.00%
|
|
| C000064681 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064681 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
95.80%
|
[18] |
| C000064681 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000064681 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
4.10%
|
|
| C000191232 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000191232 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.40%
|
|
| C000191232 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000191232 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.50%
|
|
| C000191232 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
19.10%
|
|
| C000191232 [Member] | Fitch, A Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
14.00%
|
|
| C000191232 [Member] | Fitch, AA Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.00%
|
|
| C000191232 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000191232 [Member] | Moody's, Aaa Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.90%
|
|
| C000191232 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
34.10%
|
|
| C000191232 [Member] | Tax Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.20%
|
|
| C000191232 [Member] | Sales And Excise Tax Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.60%
|
|
| C000191232 [Member] | Universities Dormitories [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.80%
|
|
| C000191232 [Member] | Universities Colleges [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.90%
|
|
| C000191232 [Member] | Airport Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.60%
|
|
| C000191232 [Member] | Multi Family Housing Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.80%
|
|
| C000191232 [Member] | Miscellaneous Revenue Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
7.10%
|
|
| C000191232 [Member] | Secondary Schools [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
8.20%
|
|
| C000191232 [Member] | Healthcare Revenue Hospitals [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.30%
|
|
| C000191232 [Member] | Healthcare Revenue Long Term Care [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
15.60%
|
|
| C000191232 [Member] | Unclassified Sector [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
26.40%
|
|
| C000191232 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000191232 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.50%
|
|
| C000191232 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000191232 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000103072 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000103072 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.40%
|
|
| C000103072 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000103072 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.50%
|
|
| C000103072 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
19.10%
|
|
| C000103072 [Member] | Fitch, A Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
14.00%
|
|
| C000103072 [Member] | Fitch, AA Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.00%
|
|
| C000103072 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000103072 [Member] | Moody's, Aaa Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.90%
|
|
| C000103072 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
34.10%
|
|
| C000103072 [Member] | Tax Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.20%
|
|
| C000103072 [Member] | Sales And Excise Tax Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.60%
|
|
| C000103072 [Member] | Universities Dormitories [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.80%
|
|
| C000103072 [Member] | Universities Colleges [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.90%
|
|
| C000103072 [Member] | Airport Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.60%
|
|
| C000103072 [Member] | Multi Family Housing Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.80%
|
|
| C000103072 [Member] | Miscellaneous Revenue Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
7.10%
|
|
| C000103072 [Member] | Secondary Schools [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
8.20%
|
|
| C000103072 [Member] | Healthcare Revenue Hospitals [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.30%
|
|
| C000103072 [Member] | Healthcare Revenue Long Term Care [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
15.60%
|
|
| C000103072 [Member] | Unclassified Sector [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
26.40%
|
|
| C000103072 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000103072 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.50%
|
|
| C000103072 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000103072 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000006490 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000006490 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.40%
|
|
| C000006490 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000006490 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.50%
|
|
| C000006490 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
19.10%
|
|
| C000006490 [Member] | Fitch, A Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
14.00%
|
|
| C000006490 [Member] | Fitch, AA Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.00%
|
|
| C000006490 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000006490 [Member] | Moody's, Aaa Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.90%
|
|
| C000006490 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
34.10%
|
|
| C000006490 [Member] | Tax Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.20%
|
|
| C000006490 [Member] | Sales And Excise Tax Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.60%
|
|
| C000006490 [Member] | Universities Dormitories [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.80%
|
|
| C000006490 [Member] | Universities Colleges [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.90%
|
|
| C000006490 [Member] | Airport Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.60%
|
|
| C000006490 [Member] | Multi Family Housing Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.80%
|
|
| C000006490 [Member] | Miscellaneous Revenue Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
7.10%
|
|
| C000006490 [Member] | Secondary Schools [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
8.20%
|
|
| C000006490 [Member] | Healthcare Revenue Hospitals [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.30%
|
|
| C000006490 [Member] | Healthcare Revenue Long Term Care [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
15.60%
|
|
| C000006490 [Member] | Unclassified Sector [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
26.40%
|
|
| C000006490 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006490 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.50%
|
|
| C000006490 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006490 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000006489 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000006489 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.40%
|
|
| C000006489 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000006489 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.50%
|
|
| C000006489 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
19.10%
|
|
| C000006489 [Member] | Fitch, A Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
14.00%
|
|
| C000006489 [Member] | Fitch, AA Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.00%
|
|
| C000006489 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000006489 [Member] | Moody's, Aaa Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.90%
|
|
| C000006489 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
34.10%
|
|
| C000006489 [Member] | Tax Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.20%
|
|
| C000006489 [Member] | Sales And Excise Tax Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.60%
|
|
| C000006489 [Member] | Universities Dormitories [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.80%
|
|
| C000006489 [Member] | Universities Colleges [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.90%
|
|
| C000006489 [Member] | Airport Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.60%
|
|
| C000006489 [Member] | Multi Family Housing Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.80%
|
|
| C000006489 [Member] | Miscellaneous Revenue Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
7.10%
|
|
| C000006489 [Member] | Secondary Schools [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
8.20%
|
|
| C000006489 [Member] | Healthcare Revenue Hospitals [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.30%
|
|
| C000006489 [Member] | Healthcare Revenue Long Term Care [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
15.60%
|
|
| C000006489 [Member] | Unclassified Sector [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
26.40%
|
|
| C000006489 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006489 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.50%
|
|
| C000006489 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006489 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000006488 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.00%
|
|
| C000006488 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.40%
|
|
| C000006488 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000006488 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.50%
|
|
| C000006488 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
19.10%
|
|
| C000006488 [Member] | Fitch, A Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
14.00%
|
|
| C000006488 [Member] | Fitch, AA Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.00%
|
|
| C000006488 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000006488 [Member] | Moody's, Aaa Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.90%
|
|
| C000006488 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
34.10%
|
|
| C000006488 [Member] | Tax Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.20%
|
|
| C000006488 [Member] | Sales And Excise Tax Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.60%
|
|
| C000006488 [Member] | Universities Dormitories [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.80%
|
|
| C000006488 [Member] | Universities Colleges [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
3.90%
|
|
| C000006488 [Member] | Airport Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.60%
|
|
| C000006488 [Member] | Multi Family Housing Revenue [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
6.80%
|
|
| C000006488 [Member] | Miscellaneous Revenue Other [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
7.10%
|
|
| C000006488 [Member] | Secondary Schools [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
8.20%
|
|
| C000006488 [Member] | Healthcare Revenue Hospitals [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
12.30%
|
|
| C000006488 [Member] | Healthcare Revenue Long Term Care [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
15.60%
|
|
| C000006488 [Member] | Unclassified Sector [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
26.40%
|
|
| C000006488 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006488 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.50%
|
|
| C000006488 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.00%
|
|
| C000006488 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.50%
|
|
| C000118060 [Member] | Fitch, CC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.30%
|
|
| C000118060 [Member] | Fitch, CCC Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
11.40%
|
|
| C000118060 [Member] | Fitch, B Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
39.00%
|
|
| C000118060 [Member] | Fitch, BB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
45.00%
|
|
| C000118060 [Member] | Fitch, BBB Rating [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.40%
|
|
| C000118060 [Member] | Money Market Funds Quality [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
| C000118060 [Member] | Not Rated [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
1.50%
|
|
| C000118060 [Member] | Non Fixed Income [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000118060 [Member] | Fixed Income Securities [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
97.60%
|
[19] |
| C000118060 [Member] | Equity [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
0.10%
|
|
| C000118060 [Member] | Money Market Funds [Member] |
|
|
| Holdings [Line Items] |
|
|
| Percent of Total Investments |
2.30%
|
|
|
|