Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	NORTHERN FUNDS
Prospectus Date	rr_ProspectusDate	Jul. 31, 2013
NORTHERN TECHNOLOGY FUND
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	TECHNOLOGY FUND
Objective [Heading]	rr_ObjectiveHeading	INVESTMENT OBJECTIVE
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide long-term capital appreciation by investing principally in equity securities and securities of companies that develop, produce or distribute products and services related to technology.
Expense [Heading]	rr_ExpenseHeading	FEES AND EXPENSES OF THE FUND
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	July 31, 2014
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	PORTFOLIO TURNOVER.
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 42.66% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	42.66%
Expense Example [Heading]	rr_ExpenseExampleHeading	EXAMPLE
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	PRINCIPAL INVESTMENT STRATEGIES
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	In seeking to achieve its investment objective, the Fund will invest, under normal circumstances, at least 80% of its net assets in securities of companies principally engaged in technology business activities. In considering whether an issuer is principally engaged in technology business activities, the Fund's investment adviser will consider whether a company is classified as such in the GICS Information Technology Sector or is listed in the NYSE Arca Tech 100SM Index or other similar technology indices. Companies engaged in businesses related to the following products and services also are considered by the Fund's investment adviser to be engaged in technology business activities whether or not they are classified as such or listed in a technology index: industrial and business machines; communications; computer hardware and software and computer services and peripheral products; electronics; electronic media; internet; biotechnology; health care and health care equipment; aerospace and defense; financial administration; television and video equipment and services; satellite technology and equipment; semiconductors; and alternative energy. The Fund may invest more than 25% of its total assets in technology companies that develop or sell computer hardware or software and peripheral products, including computer components. The Fund may invest in technology companies without regard to their size. Using fundamental research and quantitative analysis, the Fund's investment adviser buys stocks of technology companies that it believes have the potential to appreciate in value over the next one- to three-year period. Similarly, the Fund's investment adviser sells securities it believes no longer have these or other favorable characteristics. The team also may sell securities to maintain the desired portfolio composition of or diversification within the Fund. The Fund's investment adviser selects investments based on factors including, but not limited to a company's prospects relating to: Sustainability of earnings growth; Competitive leadership of its products or market niches; Management depth, transparency and credibility; and Valuation on an absolute basis as well as compared to securities of other technology-related companies and the stock's own historical norms. The Fund may make significant investments in initial public offerings ("IPOs") Many of the companies in which the Fund invests retain their earnings to finance current and future growth. These companies generally pay little or no dividends. The Fund's investment adviser may engage in active trading, and will not consider portfolio turnover a limiting factor in making decisions for the Fund.
Strategy Portfolio Concentration [Text]	rr_StrategyPortfolioConcentration	In seeking to achieve its investment objective, the Fund will invest, under normal circumstances, at least 80% of its net assets in securities of companies principally engaged in technology business activities.
Risk [Heading]	rr_RiskHeading	PRINCIPAL RISKS
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	MARKET RISK is the risk that the value of equity securities owned by the Fund may decline, at times sharply and unpredictably, because of economic changes or other events that affect individual issuers or large portions of the market. It includes the risk that a particular style of investing, such as growth or value, may underperform the market generally. MANAGEMENT RISK is the risk that a strategy used by the Fund's investment adviser may fail to produce the intended results. SMALL CAP STOCK RISK is the risk that stocks of smaller companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Small companies may have limited product lines or financial resources, or may be dependent upon a small or inexperienced management group, and their securities may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally the smaller the company size, the greater the risk. TECHNOLOGY SECURITIES RISK is the risk that securities of technology companies may be subject to greater price volatility than securities of companies in other sectors. These securities may fall in and out of favor with investors rapidly, which may cause sudden selling and dramatically lower market prices. Technology securities also may be affected adversely by changes in technology, consumer and business purchasing patterns, government regulation and/or obsolete products or services. In addition, a rising interest rate environment tends to negatively affect technology companies. MID CAP STOCK RISK is the risk that stocks of mid-sized companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Mid-sized companies may have limited product lines or financial resources, and may be dependent upon a particular niche of the market. COMPUTER SECTOR RISK is the risk that the Fund may be adversely affected by its investments in companies in the computer and related industries (including software and computer services). These companies can be significantly affected by competitive pressure. Profitability can also be affected by changing domestic and international demand, research and development costs and product obsolescence. An increasing number of companies and new product offerings also can lead to slower selling cycles. PORTFOLIO TURNOVER RISK is the risk that high portfolio turnover is likely to lead to increased Fund expenses that may result in lower investment returns. High portfolio turnover also is likely to result in higher short-term capital gains taxable to shareholders. As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any mutual fund, it is possible to lose money on an investment in the Fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	FUND PERFORMANCE
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. Updated performance information for the Fund is available and may be obtained on the Fund’s Web site at www.northernfunds.com or by calling 800-595-9111.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-595-9111
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.northernfunds.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	CALENDAR YEAR TOTAL RETURN*
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	* Year to date total return for the six months ended June 30, 2013 is 2.34%. For the periods shown in the bar chart above, the highest quarterly return was 22.33% in the second quarter of 2003, and the lowest quarterly return was (23.74)% in the fourth quarter of 2008.
Performance Table Heading	rr_PerformanceTableHeading	AVERAGE ANNUAL TOTAL RETURN (For the periods ended December 31, 2012)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
NORTHERN TECHNOLOGY FUND | NORTHERN TECHNOLOGY FUND
Risk/Return:	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther	none
Management Fees	rr_ManagementFeesOverAssets	1.00%
Other Expenses	rr_OtherExpensesOverAssets	0.53%
Administration Fees	rr_Component1OtherExpensesOverAssets	0.15%
Transfer Agency Fees	rr_Component2OtherExpensesOverAssets	0.10%
Other Operating Expenses	rr_Component3OtherExpensesOverAssets	0.28%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.53%
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.28%)	[1]
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	1.25%
1 Year	rr_ExpenseExampleYear01	127
3 Years	rr_ExpenseExampleYear03	456
5 Years	rr_ExpenseExampleYear05	808
10 Years	rr_ExpenseExampleYear10	$ 1,800
2003	rr_AnnualReturn2003	55.00%
2004	rr_AnnualReturn2004	3.05%
2005	rr_AnnualReturn2005	(1.69%)
2006	rr_AnnualReturn2006	5.51%
2007	rr_AnnualReturn2007	16.40%
2008	rr_AnnualReturn2008	(41.70%)
2009	rr_AnnualReturn2009	42.67%
2010	rr_AnnualReturn2010	24.09%
2011	rr_AnnualReturn2011	(2.72%)
2012	rr_AnnualReturn2012	13.40%
Year to Date Return, Label	rr_YearToDateReturnLabel	Year to date total return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Jun. 30, 2013
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	2.34%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest quarterly return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2003
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	22.33%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest quarterly return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(23.74%)
1-Year	rr_AverageAnnualReturnYear01	13.40%
5-Year	rr_AverageAnnualReturnYear05	2.63%
10-Year	rr_AverageAnnualReturnYear10	8.18%
Since Inception	rr_AverageAnnualReturnSinceInception	7.75%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 01, 1996
NORTHERN TECHNOLOGY FUND | Return after taxes on distributions | NORTHERN TECHNOLOGY FUND
Risk/Return:	rr_RiskReturnAbstract
1-Year	rr_AverageAnnualReturnYear01	13.40%
5-Year	rr_AverageAnnualReturnYear05	2.63%
10-Year	rr_AverageAnnualReturnYear10	8.18%
Since Inception	rr_AverageAnnualReturnSinceInception	6.51%
NORTHERN TECHNOLOGY FUND | Return after taxes on distributions and sale of Fund shares | NORTHERN TECHNOLOGY FUND
Risk/Return:	rr_RiskReturnAbstract
1-Year	rr_AverageAnnualReturnYear01	8.71%
5-Year	rr_AverageAnnualReturnYear05	2.26%
10-Year	rr_AverageAnnualReturnYear10	7.27%
Since Inception	rr_AverageAnnualReturnSinceInception	6.44%
NORTHERN TECHNOLOGY FUND | S&P 500® Index (reflects no deduction for fees, expenses, or taxes)
Risk/Return:	rr_RiskReturnAbstract
1-Year	rr_AverageAnnualReturnYear01	16.00%
5-Year	rr_AverageAnnualReturnYear05	1.66%
10-Year	rr_AverageAnnualReturnYear10	7.10%
Since Inception	rr_AverageAnnualReturnSinceInception	6.78%

[1] Northern Trust Investments, Inc. has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than acquired fund fees and expenses; a portion of the compensation paid to each Trustee who is not an officer, director or employee of Northern Trust Corporation or its subsidiaries; expenses related to third-party consultants engaged by the Board of Trustees of the Trust; membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; and extraordinary expenses and interest, if any) to the extent the "Total Annual Fund Operating Expenses" exceed 1.25%. This contractual limitation may not be terminated before July 31, 2014 without the approval of the Board of Trustees. Northern Trust Investments, Inc. serves as the investment adviser and administrator to the Fund. The Northern Trust Company, an affiliate of Northern Trust Investments, Inc., serves as transfer agent, custodian and sub-administrator to the Fund.