| Form N-CSR Cover | 6 Months Ended |
| Nov. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | JOHN HANCOCK SOVEREIGN BOND FUND |
| Entity Central Index Key | 0000045288 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Nov. 30, 2024 |
| Shareholder Report | 6 Months Ended |
| Nov. 30, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | JOHN HANCOCK SOVEREIGN BOND FUND |
| Entity Central Index Key | 0000045288 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Nov. 30, 2024 |
| C000001854 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | John Hancock Bond Fund |
| Class Name | Class A |
| Trading Symbol | JHNBX |
| Annual or Semi-Annual Statement [Text Block] | This semiannual shareholder report |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the fund at jhinvestments.com/documents |
| Additional Information Phone Number | 800-225-5291 |
| Additional Information Website | jhinvestments.com/documents |
| Expenses [Text Block] | What were the fund costs during the last six months ? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage Bond Fund $ 0.76 % |
| Expenses Paid, Amount | $ 39 |
| Expense Ratio, Percent | 0.76% |
| Net Assets | $ 26,751,405,130 |
| Holdings Count | Holding | 1,090 |
| Investment Company Portfolio Turnover | 49% |
| Additional Fund Statistics [Text Block] | Fund Statistics Fund net assets $ Total number of portfolio holdings 1,090 Portfolio turnover rate 49 % |
| Holdings [Text Block] | Graphical Representation of Holdings The tables below show the investment makeup of the fund, representing a Portfolio Composition Corporate bonds 36.3 % U.S. Government Agency 34.7 % U.S. Government 20.1 % Asset-backed securities 4.6 % Collateralized mortgage obligations – Commercial and residential 2.4 % Collateralized mortgage obligations – U.S. Government Agency 0.9 % Short-term investments and other 1.0 % Quality Composition Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time. |
| Credit Quality Explanation [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. |
| Credit Ratings Selection [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. |
| C000001856 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | John Hancock Bond Fund |
| Class Name | Class C |
| Trading Symbol | JHCBX |
| Annual or Semi-Annual Statement [Text Block] | This semiannual shareholder report |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the fund at jhinvestments.com/documents |
| Additional Information Phone Number | 800-225-5291 |
| Additional Information Website | jhinvestments.com/documents |
| Expenses [Text Block] | What were the fund costs during the last six months ? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage Bond Fund $ 1.46 % |
| Expenses Paid, Amount | $ 75 |
| Expense Ratio, Percent | 1.46% |
| Net Assets | $ 26,751,405,130 |
| Holdings Count | Holding | 1,090 |
| Investment Company Portfolio Turnover | 49% |
| Additional Fund Statistics [Text Block] | Fund Statistics Fund net assets $ Total number of portfolio holdings 1,090 Portfolio turnover rate 49 % |
| Holdings [Text Block] | Graphical Representation of Holdings The tables below show the investment makeup of the fund, representing a Portfolio Composition Corporate bonds 36.3 % U.S. Government Agency 34.7 % U.S. Government 20.1 % Asset-backed securities 4.6 % Collateralized mortgage obligations – Commercial and residential 2.4 % Collateralized mortgage obligations – U.S. Government Agency 0.9 % Short-term investments and other 1.0 % Quality Composition Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time. |
| Credit Quality Explanation [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. |
| Credit Ratings Selection [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. |
| C000001857 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | John Hancock Bond Fund |
| Class Name | Class I |
| Trading Symbol | JHBIX |
| Annual or Semi-Annual Statement [Text Block] | This semiannual shareholder report |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the fund at jhinvestments.com/documents |
| Additional Information Phone Number | 800-225-5291 |
| Additional Information Website | jhinvestments.com/documents |
| Expenses [Text Block] | What were the fund costs during the last six months ? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage Bond Fund $ 0.46 % |
| Expenses Paid, Amount | $ 24 |
| Expense Ratio, Percent | 0.46% |
| Net Assets | $ 26,751,405,130 |
| Holdings Count | Holding | 1,090 |
| Investment Company Portfolio Turnover | 49% |
| Additional Fund Statistics [Text Block] | Fund Statistics Fund net assets $ Total number of portfolio holdings 1,090 Portfolio turnover rate 49 % |
| Holdings [Text Block] | Graphical Representation of Holdings The tables below show the investment makeup of the fund, representing a Portfolio Composition Corporate bonds 36.3 % U.S. Government Agency 34.7 % U.S. Government 20.1 % Asset-backed securities 4.6 % Collateralized mortgage obligations – Commercial and residential 2.4 % Collateralized mortgage obligations – U.S. Government Agency 0.9 % Short-term investments and other 1.0 % Quality Composition Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time. |
| Credit Quality Explanation [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. |
| Credit Ratings Selection [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. |
| C000153977 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | John Hancock Bond Fund |
| Class Name | Class NAV |
| No Trading Symbol Flag | true |
| Annual or Semi-Annual Statement [Text Block] | This semiannual shareholder report |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the fund at jhinvestments.com/underlying-funds |
| Additional Information Phone Number | 800-344-1029 |
| Additional Information Website | jhinvestments.com/underlying-funds |
| Expenses [Text Block] | What were the fund costs during the last six months ? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage Bond Fund $ 0.35 % |
| Expenses Paid, Amount | $ 18 |
| Expense Ratio, Percent | 0.35% |
| Net Assets | $ 26,751,405,130 |
| Holdings Count | Holding | 1,090 |
| Investment Company Portfolio Turnover | 49% |
| Additional Fund Statistics [Text Block] | Fund Statistics Fund net assets $ Total number of portfolio holdings 1,090 Portfolio turnover rate 49 % |
| Holdings [Text Block] | Graphical Representation of Holdings The tables below show the investment makeup of the fund, representing a Portfolio Composition Corporate bonds 36.3 % U.S. Government Agency 34.7 % U.S. Government 20.1 % Asset-backed securities 4.6 % Collateralized mortgage obligations – Commercial and residential 2.4 % Collateralized mortgage obligations – U.S. Government Agency 0.9 % Short-term investments and other 1.0 % Quality Composition Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time. |
| Credit Quality Explanation [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. |
| Credit Ratings Selection [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. |
| C000113488 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | John Hancock Bond Fund |
| Class Name | Class R2 |
| Trading Symbol | JHRBX |
| Annual or Semi-Annual Statement [Text Block] | This semiannual shareholder report |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the fund at jhinvestments.com/documents |
| Additional Information Phone Number | 800-225-5291 |
| Additional Information Website | jhinvestments.com/documents |
| Expenses [Text Block] | What were the fund costs during the last six months ? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage Bond Fund $ 0.85 % |
| Expenses Paid, Amount | $ 44 |
| Expense Ratio, Percent | 0.85% |
| Net Assets | $ 26,751,405,130 |
| Holdings Count | Holding | 1,090 |
| Investment Company Portfolio Turnover | 49% |
| Additional Fund Statistics [Text Block] | Fund Statistics Fund net assets $ Total number of portfolio holdings 1,090 Portfolio turnover rate 49 % |
| Holdings [Text Block] | Graphical Representation of Holdings The tables below show the investment makeup of the fund, representing a Portfolio Composition Corporate bonds 36.3 % U.S. Government Agency 34.7 % U.S. Government 20.1 % Asset-backed securities 4.6 % Collateralized mortgage obligations – Commercial and residential 2.4 % Collateralized mortgage obligations – U.S. Government Agency 0.9 % Short-term investments and other 1.0 % Quality Composition Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time. |
| Credit Quality Explanation [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. |
| Credit Ratings Selection [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. |
| C000153978 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | John Hancock Bond Fund |
| Class Name | Class R4 |
| Trading Symbol | JBFRX |
| Annual or Semi-Annual Statement [Text Block] | This semiannual shareholder report |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the fund at jhinvestments.com/documents |
| Additional Information Phone Number | 800-225-5291 |
| Additional Information Website | jhinvestments.com/documents |
| Expenses [Text Block] | What were the fund costs during the last six months ? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage Bond Fund $ 0.60 % |
| Expenses Paid, Amount | $ 31 |
| Expense Ratio, Percent | 0.60% |
| Net Assets | $ 26,751,405,130 |
| Holdings Count | Holding | 1,090 |
| Investment Company Portfolio Turnover | 49% |
| Additional Fund Statistics [Text Block] | Fund Statistics Fund net assets $ Total number of portfolio holdings 1,090 Portfolio turnover rate 49 % |
| Holdings [Text Block] | Graphical Representation of Holdings The tables below show the investment makeup of the fund, representing a Portfolio Composition Corporate bonds 36.3 % U.S. Government Agency 34.7 % U.S. Government 20.1 % Asset-backed securities 4.6 % Collateralized mortgage obligations – Commercial and residential 2.4 % Collateralized mortgage obligations – U.S. Government Agency 0.9 % Short-term investments and other 1.0 % Quality Composition Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time. |
| Credit Quality Explanation [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. |
| Credit Ratings Selection [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. |
| C000106442 [Member] | |
| Shareholder Report [Line Items] | |
| Fund Name | John Hancock Bond Fund |
| Class Name | Class R6 |
| Trading Symbol | JHBSX |
| Annual or Semi-Annual Statement [Text Block] | This semiannual shareholder report |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the fund at jhinvestments.com/documents |
| Additional Information Phone Number | 800-225-5291 |
| Additional Information Website | jhinvestments.com/documents |
| Expenses [Text Block] | What were the fund costs during the last six months ? (Based on a hypothetical $10,000 investment) Fund (Class) Costs of a $10,000 investment Costs paid as a percentage Bond Fund $ 0.35 % |
| Expenses Paid, Amount | $ 18 |
| Expense Ratio, Percent | 0.35% |
| Net Assets | $ 26,751,405,130 |
| Holdings Count | Holding | 1,090 |
| Investment Company Portfolio Turnover | 49% |
| Additional Fund Statistics [Text Block] | Fund Statistics Fund net assets $ Total number of portfolio holdings 1,090 Portfolio turnover rate 49 % |
| Holdings [Text Block] | Graphical Representation of Holdings The tables below show the investment makeup of the fund, representing a Portfolio Composition Corporate bonds 36.3 % U.S. Government Agency 34.7 % U.S. Government 20.1 % Asset-backed securities 4.6 % Collateralized mortgage obligations – Commercial and residential 2.4 % Collateralized mortgage obligations – U.S. Government Agency 0.9 % Short-term investments and other 1.0 % Quality Composition Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time. |
| Credit Quality Explanation [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. “Not rated” securities are those with no ratings available from these agencies. All ratings are as of 11-30-24 and do not reflect subsequent downgrades or upgrades, if any. |
| Credit Ratings Selection [Text Block] | Ratings are from Moody’s Investors Service, Inc. If not available, we have used S&P Global Ratings. In the absence of ratings from these agencies, we have used Fitch Ratings, Inc. |
| Shareholder Report, Holdings (Details) | Nov. 30, 2024 |
| C000001854 [Member] | US Government Debt Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000001854 [Member] | Moody's, Aaa Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000001854 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000001854 [Member] | Standard & Poor's, AA Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000001854 [Member] | Standard & Poor's, A Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| C000001854 [Member] | Standard & Poor's, BBB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.60% |
| C000001854 [Member] | Standard & Poor's, BB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000001854 [Member] | Standard & Poor's, B Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000001854 [Member] | CCC and below [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| C000001854 [Member] | Not Rated [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000001854 [Member] | Short term investments and other Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000001854 [Member] | Mortgage Backed Securities Issued by US Government Sponsored Enterprises Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000001854 [Member] | Asset-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000001854 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.30% |
| C000001854 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000001854 [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000001854 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000001854 [Member] | US Government Debt Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000001854 [Member] | Short term investments and other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000001856 [Member] | US Government Debt Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000001856 [Member] | Moody's, Aaa Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000001856 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000001856 [Member] | Standard & Poor's, AA Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000001856 [Member] | Standard & Poor's, A Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| C000001856 [Member] | Standard & Poor's, BBB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.60% |
| C000001856 [Member] | Standard & Poor's, BB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000001856 [Member] | Standard & Poor's, B Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000001856 [Member] | CCC and below [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| C000001856 [Member] | Not Rated [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000001856 [Member] | Short term investments and other Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000001856 [Member] | Mortgage Backed Securities Issued by US Government Sponsored Enterprises Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000001856 [Member] | Asset-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000001856 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.30% |
| C000001856 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000001856 [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000001856 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000001856 [Member] | US Government Debt Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000001856 [Member] | Short term investments and other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000001857 [Member] | US Government Debt Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000001857 [Member] | Moody's, Aaa Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000001857 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000001857 [Member] | Standard & Poor's, AA Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000001857 [Member] | Standard & Poor's, A Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| C000001857 [Member] | Standard & Poor's, BBB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.60% |
| C000001857 [Member] | Standard & Poor's, BB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000001857 [Member] | Standard & Poor's, B Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000001857 [Member] | CCC and below [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| C000001857 [Member] | Not Rated [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000001857 [Member] | Short term investments and other Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000001857 [Member] | Mortgage Backed Securities Issued by US Government Sponsored Enterprises Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000001857 [Member] | Asset-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000001857 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.30% |
| C000001857 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000001857 [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000001857 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000001857 [Member] | US Government Debt Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000001857 [Member] | Short term investments and other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000153977 [Member] | US Government Debt Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000153977 [Member] | Moody's, Aaa Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000153977 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000153977 [Member] | Standard & Poor's, AA Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000153977 [Member] | Standard & Poor's, A Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| C000153977 [Member] | Standard & Poor's, BBB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.60% |
| C000153977 [Member] | Standard & Poor's, BB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000153977 [Member] | Standard & Poor's, B Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000153977 [Member] | CCC and below [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| C000153977 [Member] | Not Rated [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000153977 [Member] | Short term investments and other Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000153977 [Member] | Mortgage Backed Securities Issued by US Government Sponsored Enterprises Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000153977 [Member] | Asset-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000153977 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.30% |
| C000153977 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000153977 [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000153977 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000153977 [Member] | US Government Debt Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000153977 [Member] | Short term investments and other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000113488 [Member] | US Government Debt Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000113488 [Member] | Moody's, Aaa Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000113488 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000113488 [Member] | Standard & Poor's, AA Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000113488 [Member] | Standard & Poor's, A Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| C000113488 [Member] | Standard & Poor's, BBB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.60% |
| C000113488 [Member] | Standard & Poor's, BB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000113488 [Member] | Standard & Poor's, B Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000113488 [Member] | CCC and below [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| C000113488 [Member] | Not Rated [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000113488 [Member] | Short term investments and other Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000113488 [Member] | Mortgage Backed Securities Issued by US Government Sponsored Enterprises Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000113488 [Member] | Asset-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000113488 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.30% |
| C000113488 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000113488 [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000113488 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000113488 [Member] | US Government Debt Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000113488 [Member] | Short term investments and other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000153978 [Member] | US Government Debt Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000153978 [Member] | Moody's, Aaa Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000153978 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000153978 [Member] | Standard & Poor's, AA Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000153978 [Member] | Standard & Poor's, A Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| C000153978 [Member] | Standard & Poor's, BBB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.60% |
| C000153978 [Member] | Standard & Poor's, BB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000153978 [Member] | Standard & Poor's, B Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000153978 [Member] | CCC and below [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| C000153978 [Member] | Not Rated [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000153978 [Member] | Short term investments and other Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000153978 [Member] | Mortgage Backed Securities Issued by US Government Sponsored Enterprises Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000153978 [Member] | Asset-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000153978 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.30% |
| C000153978 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000153978 [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000153978 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000153978 [Member] | US Government Debt Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000153978 [Member] | Short term investments and other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000106442 [Member] | US Government Debt Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000106442 [Member] | Moody's, Aaa Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
| C000106442 [Member] | US Government Corporations and Agencies Securities Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000106442 [Member] | Standard & Poor's, AA Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000106442 [Member] | Standard & Poor's, A Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| C000106442 [Member] | Standard & Poor's, BBB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.60% |
| C000106442 [Member] | Standard & Poor's, BB Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| C000106442 [Member] | Standard & Poor's, B Rating [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000106442 [Member] | CCC and below [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| C000106442 [Member] | Not Rated [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000106442 [Member] | Short term investments and other Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000106442 [Member] | Mortgage Backed Securities Issued by US Government Sponsored Enterprises Quality [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000106442 [Member] | Asset-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.60% |
| C000106442 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 36.30% |
| C000106442 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| C000106442 [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| C000106442 [Member] | US Government Corporations and Agencies Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| C000106442 [Member] | US Government Debt Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.10% |
| C000106442 [Member] | Short term investments and other [Member] | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
