v3.26.1
Shareholder Report, Line Graph (Details) - USD ($)
4 Months Ended 5 Months Ended 11 Months Ended 12 Months Ended 16 Months Ended 17 Months Ended 23 Months Ended 24 Months Ended 28 Months Ended 29 Months Ended 35 Months Ended 36 Months Ended 40 Months Ended 47 Months Ended 48 Months Ended 59 Months Ended 60 Months Ended 71 Months Ended 72 Months Ended 83 Months Ended 84 Months Ended 96 Months Ended 108 Months Ended 120 Months Ended
Dec. 18, 2023
Feb. 08, 2023
Jul. 09, 2019
May 31, 2016
May 31, 2023
May 31, 2024
May 31, 2020
May 31, 2026
May 31, 2017
May 31, 2024
May 31, 2025
May 31, 2021
May 31, 2018
May 31, 2025
May 31, 2026
May 31, 2022
May 31, 2019
May 31, 2026
May 31, 2023
May 31, 2020
May 31, 2024
May 31, 2021
May 31, 2025
May 31, 2022
May 31, 2026
May 31, 2023
May 31, 2024
May 31, 2025
May 31, 2026
C000106430 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Income Fund (Class R6/JSNWX)                                          
Accumulated Value       $ 1,000,000         $ 1,033,873.22       $ 1,033,412.464061       $ 1,076,085.753985     $ 1,129,116.87407   $ 1,226,370.341276   $ 1,137,995.237041   $ 1,130,878.522087 $ 1,177,972.951657 $ 1,253,084.123432 $ 1,325,475.382192
C000078713 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Income Fund (Class R5/JSNVX)                                          
Accumulated Value       10,000         10,331.9048       10,321.986275       10,742.96993     11,266.81401   12,231.924453   11,325.871559   11,268.19116 11,731.624255 12,452.239158 13,187.727302
C000078712 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Income Fund (Class R4/JSNFX)                                          
Accumulated Value       10,000         10,311.1825       10,281.302652       10,679.339789     11,178.369318   12,110.118594   11,192.599213   11,094.897 11,528.135642 12,232.73241 12,929.000945
C000113489 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Income Fund (Class R2/JSNSX)                                          
Accumulated Value       10,000         10,285.5792       10,229.582038       10,599.168551     11,067.062275   11,960.678084   11,024.833127   10,920.085967 11,318.234704 11,959.907307 12,609.328839
C000001866 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Income Fund (Class I/JSTIX)                                          
Accumulated Value       250,000         258,182.635       257,397.968918       268,147.592779     280,608.34706   304,482.906498   282,196.243619   280,111.504759 291,950.504342 309,696.131847 327,809.880769
C000001865 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Income Fund (Class C/JSTCX)                                          
Accumulated Value       10,000         10,223.5225       10,108.732176       10,411.359515     10,803.768861   11,604.172019   10,633.532347   10,468.659534 10,765.59186 11,326.130498 11,869.369772
C000001863 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Income Fund (Class A/JHFIX)                                          
Accumulated Value       9,600         9,883.334304       9,841.02039       10,206.676394     10,665.601838   11,536.645648   10,646.140738   10,554.939189 10,930.328979 11,579.919305 12,220.335857
C000212730 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Managed Account Shares Investment-Grade Corporate Bond Portfolio (Investment-Grade Corporate Bond Portfolio/JMABX)                                          
Accumulated Value     $ 10,000       $ 10,373.8283         $ 11,109.339573       $ 10,049.270727     $ 10,068.338314   $ 10,787.425178   $ 11,522.819271   $ 12,334.472142        
C000212731 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio (Non-Investment-Grade Corporate Bond Portfolio/JMADX)                                          
Accumulated Value     10,000       9,638.0097         11,053.981654       10,393.424561     10,253.373997   11,482.979421   12,336.764778   13,263.913116        
C000212732 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Managed Account Shares Securitized Debt Portfolio (Securitized Debt Portfolio/JMAEX)                                          
Accumulated Value     10,000       10,237.3293         10,751.020978       10,108.362788     10,196.555524   10,873.178352   11,682.649946   12,227.757252        
C000238026 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Managed Account Shares Non-Investment-Grade Municipal Bond Portfolio (Non-Investment-Grade Municipal Bond Portfolio/JHFMX)                                          
Accumulated Value   $ 10,000     $ 9,970.505         $ 10,841.066184       $ 10,948.222426       $ 11,745.870608                      
C000247081 [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Managed Account Shares Bond Completion Portfolio (Bond Completion Portfolio/JHBMX)                                          
Accumulated Value $ 10,000         $ 9,823.9645         $ 10,378.86249       $ 10,998.041555                            
Bloomberg U S Aggregate Bond C000106430 Index [Member]                                                          
Account Value [Line Items]                                                          
Accumulated Value       1,000,000         1,015,783.92       1,011,978.509016       1,076,750.841152     1,178,132.876511   1,173,363.075966   1,076,888.682781   1,053,813.047473 1,067,570.90349 1,125,848.638298 1,183,641.691346
Bloomberg U S Aggregate Bond C000001866 Index [Member]                                                          
Account Value [Line Items]                                                          
Accumulated Value       250,000         253,945.98       252,994.627254       269,187.710288     294,533.219128   293,340.768992   269,222.170696   263,453.261869 266,892.725873 281,462.159575 295,910.422837
Bloomberg U S Aggregate Bond Index [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Bloomberg U.S. Aggregate Bond Index                                          
Accumulated Value $ 10,000   10,000 $ 10,000   $ 9,919.4259 10,811.4019   $ 10,157.8392   $ 10,460.918432 10,767.63075 $ 10,119.78509   $ 10,997.907503 9,882.311735 $ 10,767.508411   9,670.552966 $ 11,781.328765 9,796.805033 $ 11,733.63076 10,331.603803 $ 10,768.886828 10,861.954781 $ 10,538.130475 $ 10,675.709035 $ 11,258.486383 $ 11,836.416913
Bloomberg Municipal Bond Index [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Bloomberg Municipal Bond Index                                          
Accumulated Value   10,000     9,900.1086         10,164.719891       10,370.827477       11,062.774583                      
Bloomberg U S Corporate Bond Index [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Bloomberg U.S. Corporate Bond Index                                          
Accumulated Value     10,000       10,735.0264         11,125.693226       9,982.051845     9,812.468563   10,244.345527   10,819.399468   11,478.744491        
ICE BofA U S High Yield Index [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               ICE BofA U.S. High Yield Index                                          
Accumulated Value     10,000       9,778.3931         11,262.279116       10,699.225413     10,681.512417   11,874.651454   12,976.139967   13,942.088627        
Bloomberg U S Securitized MBS ABS CMBS Index [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Bloomberg U.S. Securitized MBS ABS CMBS Index                                          
Accumulated Value     $ 10,000       $ 10,561.1777         $ 10,547.881283       $ 9,748.634354     $ 9,498.196324   $ 9,570.666612   $ 10,142.162603   $ 10,822.473819        
Bloomberg High Yield Municipal Bond Index [Member]                                                          
Account Value [Line Items]                                                          
Line Graph and Table Measure Name               Bloomberg High Yield Municipal Bond Index                                          
Accumulated Value   $ 10,000     $ 9,820.0531         $ 10,624.146937       $ 11,010.742645       $ 11,694.819606