Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

NORTHERN FUNDS

Prospectus Date

rr_ProspectusDate

Jul. 31, 2011

Supplement [Text Block]

cik0000916620_SupplementTextBlock

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

FIXED INCOME FUNDS

SUPPLEMENT DATED AUGUST 29, 2011 (AS REVISED AND RESTATED OCTOBER 26, 2011)

TO PROSPECTUS DATED JULY 31, 2011

Northern Trust Investments, Inc. is scheduled to increase the expense reimbursements it provides to certain Northern Funds effective as of January 1, 2012. This increase in expense reimbursements will have the effect of reducing the Total Annual Fund Operating Expenses paid by investors. The following chart illustrates the increase in expense reimbursements:

Fund	Total Annual Fund Operating Expenses After Expense Reimbursement	Operating Expense Reduction	Total Annual Fund Operating Expenses After Expense Reimbursement Effective 1/1/2012
Bond Index	0.26%	-0.10%	0.16%
Fixed Income	0.91%	-0.45%	0.46%
Global Fixed Income	1.15%	-0.35%	0.80%
High Yield Fixed Income	0.87%	-0.10%	0.77%
Short-Intermediate U.S. Government	0.93%	-0.50%	0.43%
Tax-Advantaged Ultra-Short Fixed Income	0.25%	0.00%	0.25%
Ultra-Short Fixed Income	0.25%	0.00%	0.25%
U.S. Government	0.91%	-0.50%	0.41%

These new contractual expense reimbursement arrangements are expected to continue from implementation until at least December 31, 2012.

Please retain this Supplement with your Prospectus for future reference.

NORTHERN BOND INDEX FUND

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cik0000916620_SupplementTextBlock

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

FIXED INCOME FUNDS

SUPPLEMENT DATED AUGUST 29, 2011 (AS REVISED AND RESTATED OCTOBER 26, 2011)

TO PROSPECTUS DATED JULY 31, 2011

Northern Trust Investments, Inc. is scheduled to increase the expense reimbursements it provides to certain Northern Funds effective as of January 1, 2012. This increase in expense reimbursements will have the effect of reducing the Total Annual Fund Operating Expenses paid by investors. The following chart illustrates the increase in expense reimbursements:

Fund	Total Annual Fund Operating Expenses After Expense Reimbursement	Operating Expense Reduction	Total Annual Fund Operating Expenses After Expense Reimbursement Effective 1/1/2012
Bond Index	0.26%	-0.10%	0.16%

These new contractual expense reimbursement arrangements are expected to continue from implementation until at least December 31, 2012.

Please retain this Supplement with your Prospectus for future reference.

NORTHERN FIXED INCOME FUND

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cik0000916620_SupplementTextBlock

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

FIXED INCOME FUNDS

SUPPLEMENT DATED AUGUST 29, 2011 (AS REVISED AND RESTATED OCTOBER 26, 2011)

TO PROSPECTUS DATED JULY 31, 2011

Northern Trust Investments, Inc. is scheduled to increase the expense reimbursements it provides to certain Northern Funds effective as of January 1, 2012. This increase in expense reimbursements will have the effect of reducing the Total Annual Fund Operating Expenses paid by investors. The following chart illustrates the increase in expense reimbursements:

Fund	Total Annual Fund Operating Expenses After Expense Reimbursement	Operating Expense Reduction	Total Annual Fund Operating Expenses After Expense Reimbursement Effective 1/1/2012
Fixed Income	0.91%	-0.45%	0.46%

These new contractual expense reimbursement arrangements are expected to continue from implementation until at least December 31, 2012.

Please retain this Supplement with your Prospectus for future reference.

NORTHERN GLOBAL FIXED INCOME FUND

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cik0000916620_SupplementTextBlock

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

FIXED INCOME FUNDS

SUPPLEMENT DATED AUGUST 29, 2011 (AS REVISED AND RESTATED OCTOBER 26, 2011)

TO PROSPECTUS DATED JULY 31, 2011

Northern Trust Investments, Inc. is scheduled to increase the expense reimbursements it provides to certain Northern Funds effective as of January 1, 2012. This increase in expense reimbursements will have the effect of reducing the Total Annual Fund Operating Expenses paid by investors. The following chart illustrates the increase in expense reimbursements:

Fund	Total Annual Fund Operating Expenses After Expense Reimbursement	Operating Expense Reduction	Total Annual Fund Operating Expenses After Expense Reimbursement Effective 1/1/2012
Global Fixed Income	1.15%	-0.35%	0.80%

These new contractual expense reimbursement arrangements are expected to continue from implementation until at least December 31, 2012.

Please retain this Supplement with your Prospectus for future reference.

NORTHERN HIGH YIELD FIXED INCOME FUND

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cik0000916620_SupplementTextBlock

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

FIXED INCOME FUNDS

SUPPLEMENT DATED AUGUST 29, 2011 (AS REVISED AND RESTATED OCTOBER 26, 2011)

TO PROSPECTUS DATED JULY 31, 2011

Northern Trust Investments, Inc. is scheduled to increase the expense reimbursements it provides to certain Northern Funds effective as of January 1, 2012. This increase in expense reimbursements will have the effect of reducing the Total Annual Fund Operating Expenses paid by investors. The following chart illustrates the increase in expense reimbursements:

Fund	Total Annual Fund Operating Expenses After Expense Reimbursement	Operating Expense Reduction	Total Annual Fund Operating Expenses After Expense Reimbursement Effective 1/1/2012
High Yield Fixed Income	0.87%	-0.10%	0.77%

These new contractual expense reimbursement arrangements are expected to continue from implementation until at least December 31, 2012.

Please retain this Supplement with your Prospectus for future reference.

NORTHERN SHORT-INTERMEDIATE U.S. GOVERNMENT FUND

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cik0000916620_SupplementTextBlock

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

FIXED INCOME FUNDS

SUPPLEMENT DATED AUGUST 29, 2011 (AS REVISED AND RESTATED OCTOBER 26, 2011)

TO PROSPECTUS DATED JULY 31, 2011

Northern Trust Investments, Inc. is scheduled to increase the expense reimbursements it provides to certain Northern Funds effective as of January 1, 2012. This increase in expense reimbursements will have the effect of reducing the Total Annual Fund Operating Expenses paid by investors. The following chart illustrates the increase in expense reimbursements:

Fund	Total Annual Fund Operating Expenses After Expense Reimbursement	Operating Expense Reduction	Total Annual Fund Operating Expenses After Expense Reimbursement Effective 1/1/2012
Short-Intermediate U.S. Government	0.93%	-0.50%	0.43%

These new contractual expense reimbursement arrangements are expected to continue from implementation until at least December 31, 2012.

Please retain this Supplement with your Prospectus for future reference.

NORTHERN TAX-ADVANTAGED ULTRA-SHORT FIXED INCOME FUND

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cik0000916620_SupplementTextBlock

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

FIXED INCOME FUNDS

SUPPLEMENT DATED AUGUST 29, 2011 (AS REVISED AND RESTATED OCTOBER 26, 2011)

TO PROSPECTUS DATED JULY 31, 2011

Northern Trust Investments, Inc. is scheduled to increase the expense reimbursements it provides to certain Northern Funds effective as of January 1, 2012. This increase in expense reimbursements will have the effect of reducing the Total Annual Fund Operating Expenses paid by investors. The following chart illustrates the increase in expense reimbursements:

Fund	Total Annual Fund Operating Expenses After Expense Reimbursement	Operating Expense Reduction	Total Annual Fund Operating Expenses After Expense Reimbursement Effective 1/1/2012
Tax-Advantaged Ultra-Short Fixed Income	0.25%	0.00%	0.25%

These new contractual expense reimbursement arrangements are expected to continue from implementation until at least December 31, 2012.

Please retain this Supplement with your Prospectus for future reference.

NORTHERN ULTRA-SHORT FIXED INCOME FUND

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cik0000916620_SupplementTextBlock

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

FIXED INCOME FUNDS

SUPPLEMENT DATED AUGUST 29, 2011 (AS REVISED AND RESTATED OCTOBER 26, 2011)

TO PROSPECTUS DATED JULY 31, 2011

Northern Trust Investments, Inc. is scheduled to increase the expense reimbursements it provides to certain Northern Funds effective as of January 1, 2012. This increase in expense reimbursements will have the effect of reducing the Total Annual Fund Operating Expenses paid by investors. The following chart illustrates the increase in expense reimbursements:

Fund	Total Annual Fund Operating Expenses After Expense Reimbursement	Operating Expense Reduction	Total Annual Fund Operating Expenses After Expense Reimbursement Effective 1/1/2012
Ultra-Short Fixed Income	0.25%	0.00%	0.25%

These new contractual expense reimbursement arrangements are expected to continue from implementation until at least December 31, 2012.

Please retain this Supplement with your Prospectus for future reference.

NORTHERN U.S. GOVERNMENT FUND

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

cik0000916620_SupplementTextBlock

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

FIXED INCOME FUNDS

SUPPLEMENT DATED AUGUST 29, 2011 (AS REVISED AND RESTATED OCTOBER 26, 2011)

TO PROSPECTUS DATED JULY 31, 2011

Northern Trust Investments, Inc. is scheduled to increase the expense reimbursements it provides to certain Northern Funds effective as of January 1, 2012. This increase in expense reimbursements will have the effect of reducing the Total Annual Fund Operating Expenses paid by investors. The following chart illustrates the increase in expense reimbursements:

Fund	Total Annual Fund Operating Expenses After Expense Reimbursement	Operating Expense Reduction	Total Annual Fund Operating Expenses After Expense Reimbursement Effective 1/1/2012
U.S. Government	0.91%	-0.50%	0.41%

These new contractual expense reimbursement arrangements are expected to continue from implementation until at least December 31, 2012.

Please retain this Supplement with your Prospectus for future reference.