Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	AMG FUNDS
Prospectus Date	rr_ProspectusDate	Mar. 01, 2019
AMG GW&K Trilogy Emerging Markets Equity Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<b>AMG GW&K Trilogy Emerging Markets Equity Fund</b><br/><b>(formerly AMG Trilogy Emerging Markets Equity Fund)</b>
Objective [Heading]	rr_ObjectiveHeading	<b>INVESTMENT OBJECTIVE</b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The AMG GW&K Trilogy Emerging Markets Equity Fund's (the “Fund”) investment objective is to seek long-term capital appreciation.
Expense [Heading]	rr_ExpenseHeading	<b>FEES AND EXPENSES OF THE FUND</b>
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund. If you transact in Class I shares of the Fund through a financial intermediary, you may be required to pay a commission to the financial intermediary for effecting such transactions. Such commissions are charged by the financial intermediary and are not reflected in the table or Expense Example below.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses<br/>(expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>PORTFOLIO TURNOVER</b>
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 Fund Operating Expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 24% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	24.00%
Expense Example [Heading]	rr_ExpenseExampleHeading	<b>EXPENSE EXAMPLE</b>
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example will help you compare the cost of investing in the Fund to the cost of investing in other mutual funds. The Example makes certain assumptions. It assumes that you invest $10,000 as an initial investment in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. It also assumes that your investment has a 5% total return each year and the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on the above assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>PRINCIPAL INVESTMENT STRATEGIES</b>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal circumstances, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in equity securities (generally common and preferred stocks) of issuers located in emerging market countries. GW&K Investment Management, LLC (“GW&K” or the “Subadviser”) considers equity securities to include common and preferred stocks, initial public offering (“IPO”) investments, securities convertible into equities (such as warrants and convertible bonds), and securities with equity characteristics, including, but not limited to, equity linked notes and participation notes. The Fund may allocate investments across different emerging market countries. With respect to the Fund, GW&K considers emerging market countries to be any country other than Canada, Luxembourg, the United States and the countries comprising the MSCI EAFE Index. The Fund considers an issuer to be located in an emerging market country if the issuer maintains its principal place of business in an emerging market country, its securities are traded principally in an emerging market country, it derives at least 50% of its revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country or it has at least 50% of its assets in an emerging market country. To gain exposure to foreign issuers, the Fund also may invest in American Depositary Receipts ("ADRs"), Global Depositary Receipts ("GDRs") and other depositary receipts of non-U.S. listed companies. The Fund may also invest in derivative instruments, including but not limited to swaps, such as total return swaps, equity index futures, currency forwards, exchange-traded futures, and forward foreign currency contracts. The Fund may invest in derivative instruments to gain exposure to emerging markets. The Subadviser uses a bottom-up investment process driven by fundamental research conducted by its investment analysts. Under normal market conditions, the Subadviser seeks to maintain a growth oriented focus and invest the Fund’s assets pursuant to the following core principles: — Earnings growth should drive equity returns over the long term. — Early-stage and traditional growth companies should provide the greatest opportunity. — Risk management with respect to the Fund’s portfolio should focus on avoiding losing money, rather than minimizing tracking error against the benchmark. — A disciplined investment process requires consistently identifying opportunities, evaluating potential returns and responding with timely buy/sell decisions.
Risk [Heading]	rr_RiskHeading	<b>PRINCIPAL RISKS</b>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	There is the risk that you may lose money on your investment. All investments carry a certain amount of risk, and the Fund cannot guarantee that it will achieve its investment objective. An investment in the Fund is not a deposit or obligation of any bank, is not endorsed or guaranteed by any bank, and is not insured by the Federal Deposit Insurance Corporation (“FDIC”) or any other government agency. Below are some of the risks of investing in the Fund. The risks are described in alphabetical order and not in the order of importance or potential exposure. Counterparty Risk—the counterparty to a derivatives contract may be unable or unwilling, or may be perceived as unable or unwilling, to make timely interest, principal or settlement payments or otherwise honor its obligations. Currency Risk—fluctuations in exchange rates may affect the total loss or gain on a non-U.S. dollar investment when converted back to U.S. dollars and exposure to non-U.S. currencies may subject the Fund to the risk that those currencies will decline in value relative to the U.S. dollar. Derivatives Risk—the use of derivatives involves costs, the risk that the value of derivatives may not correlate perfectly with their underlying assets, rates or indices, and the risk of mispricing or improper valuation. The use of derivatives may not succeed for various reasons, and the complexity and rapidly changing structure of derivatives markets may increase the possibility of market losses. Emerging Markets Risk—investments in emerging markets are subject to the general risks of foreign investments, as well as additional risks which can result in greater price volatility. Foreign Investment Risk—investments in foreign issuers involve additional risks (such as risks arising from less frequent trading, changes in political or social conditions, and less publicly available information about non-U.S. issuers) that differ from those associated with investments in U.S. issuers and may result in greater price volatility. Growth Stock Risk—the prices of equity securities of companies that are expected to experience relatively rapid earnings growth, or “growth stocks,” may be more sensitive to market movements because the prices tend to reflect future investor expectations rather than just current profits. IPO Risk—the prices of stocks purchased in initial public offerings (“IPOs”) can be very volatile and tend to fluctuate more widely than stocks of companies that have been publicly traded for a longer period of time. The effect of IPOs on the Fund’s performance depends on a variety of factors. Large-Capitalization Stock Risk—the stocks of large-capitalization companies are generally more mature and may not be able to reach the same levels of growth as the stocks of small- or mid-capitalization companies. Leverage Risk—borrowing and some derivative investments such as futures, forward commitment transactions and swaps may magnify smaller adverse market movements into relatively larger losses. Liquidity Risk—the Fund may not be able to dispose of particular investments, such as illiquid securities, readily at favorable times or prices or the Fund may have to sell them at a loss. Management Risk—because the Fund is an actively managed investment portfolio, security selection or focus on securities in a particular style, market sector or group of companies may cause the Fund to incur losses or underperform relative to its benchmarks or other funds with a similar investment objective. There can be no guarantee that the Subadviser’s investment techniques and risk analysis will produce the desired result. Market Risk—market prices of investments held by the Fund may fall rapidly or unpredictably due to a variety of factors, including economic, political, or market conditions or in response to events that affect particular industries or companies. Political Risk—changes in the general political and social environment of a country can have substantial effects on the value of investments exposed to that country. Sector Risk— issuers and companies that are in similar industry sectors may be similarly affected by particular economic or market events; to the extent the Fund has substantial holdings within a particular sector, the risks associated with that sector increase. Investments in the financials and information technology sectors may comprise a significant portion of the Fund’s portfolio. Unique risks of the financials sector include, but are not limited to, government regulation uncertainty, yield curve fluctuations, asset flow fluctuation, and capital market fluctuations. The information technology sector may be affected by technological obsolescence, short product cycles, falling prices and profits, competitive pressures and general market conditions. Small- and Mid-Capitalization Stock Risk—the stocks of small- and mid-capitalization companies often have greater price volatility, lower trading volume, and less liquidity than the stocks of larger, more established companies.
Risk Lose Money [Text]	rr_RiskLoseMoney	There is the risk that you may lose money on your investment.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit or obligation of any bank, is not endorsed or guaranteed by any bank, and is not insured by the Federal Deposit Insurance Corporation (“FDIC”) or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>PERFORMANCE</b>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following performance information illustrates the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s performance compares to that of a broad-based securities market index. As always, past performance of the Fund (before and after taxes) is not an indication of how the Fund will perform in the future. Effective October 1, 2016, outstanding Investor Class, Service Class and Institutional Class shares of the Fund were renamed Class N, Class I and Class Z shares, respectively. As of January 31, 2019, GW&K Investment Management, LLC became the subadviser to the Fund. Performance prior to that date reflects the performance of a previous subadviser. To obtain updated performance information please visit www.amgfunds.com or call 800.548.4539.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following performance information illustrates the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s performance compares to that of a broad-based securities market index.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800.548.4539
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.amgfunds.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	As always, past performance of the Fund (before and after taxes) is not an indication of how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Calendar Year Total Returns as of 12/31/18 (Class Z)
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best Quarter: 15.43% (1st Quarter 2012) Worst Quarter: -15.97% (3rd Quarter 2015)
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns as of 12/31/18
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 are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts (“IRAs”).
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown for Class Z shares only, and after-tax returns for Class I and Class N shares will vary.
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 are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts (“IRAs”). After-tax returns are shown for Class Z shares only, and after-tax returns for Class I and Class N shares will vary.
AMG GW&K Trilogy Emerging Markets Equity Fund | Class N
Risk/Return:	rr_RiskReturnAbstract
Management Fee	rr_ManagementFeesOverAssets	0.55%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.47%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.27%
1 Year	rr_ExpenseExampleYear01	$ 129
3 Years	rr_ExpenseExampleYear03	403
5 Years	rr_ExpenseExampleYear05	697
10 Years	rr_ExpenseExampleYear10	$ 1,534
1 Year	rr_AverageAnnualReturnYear01	(16.93%)
5 Year	rr_AverageAnnualReturnYear05	0.72%
Since Inception	rr_AverageAnnualReturnSinceInception	(0.73%)	[1]
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2012
AMG GW&K Trilogy Emerging Markets Equity Fund | Class I
Risk/Return:	rr_RiskReturnAbstract
Management Fee	rr_ManagementFeesOverAssets	0.55%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.44%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.99%
1 Year	rr_ExpenseExampleYear01	$ 101
3 Years	rr_ExpenseExampleYear03	315
5 Years	rr_ExpenseExampleYear05	547
10 Years	rr_ExpenseExampleYear10	$ 1,213
1 Year	rr_AverageAnnualReturnYear01	(16.64%)
5 Year	rr_AverageAnnualReturnYear05	1.07%
Since Inception	rr_AverageAnnualReturnSinceInception	(1.19%)	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2011
AMG GW&K Trilogy Emerging Markets Equity Fund | Class Z
Risk/Return:	rr_RiskReturnAbstract
Management Fee	rr_ManagementFeesOverAssets	0.55%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.32%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.87%
1 Year	rr_ExpenseExampleYear01	$ 89
3 Years	rr_ExpenseExampleYear03	278
5 Years	rr_ExpenseExampleYear05	482
10 Years	rr_ExpenseExampleYear10	$ 1,073
2012	rr_AnnualReturn2012	15.52%
2013	rr_AnnualReturn2013	(4.59%)
2014	rr_AnnualReturn2014	(3.50%)
2015	rr_AnnualReturn2015	(15.66%)
2016	rr_AnnualReturn2016	12.84%
2017	rr_AnnualReturn2017	38.54%
2018	rr_AnnualReturn2018	(16.69%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2012
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	15.43%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2015
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(15.97%)
1 Year	rr_AverageAnnualReturnYear01	(16.69%)
5 Year	rr_AverageAnnualReturnYear05	1.18%
Since Inception	rr_AverageAnnualReturnSinceInception	(1.09%)	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2011
AMG GW&K Trilogy Emerging Markets Equity Fund | Return After Taxes on Distributions | Class Z
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(16.83%)
5 Year	rr_AverageAnnualReturnYear05	1.02%
Since Inception	rr_AverageAnnualReturnSinceInception	(1.19%)	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2011
AMG GW&K Trilogy Emerging Markets Equity Fund | Return After Taxes on Distributions and Sale of Fund Shares | Class Z
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(9.49%)
5 Year	rr_AverageAnnualReturnYear05	1.06%
Since Inception	rr_AverageAnnualReturnSinceInception	(0.69%)	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2011
AMG GW&K Trilogy Emerging Markets Equity Fund | MSCI Emerging Markets Index (reflects no deduction for fees, expenses, or taxes) | Class N
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(14.58%)
5 Year	rr_AverageAnnualReturnYear05	1.65%
Since Inception	rr_AverageAnnualReturnSinceInception	0.88%	[1]
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2012
AMG GW&K Trilogy Emerging Markets Equity Fund | MSCI Emerging Markets Index (reflects no deduction for fees, expenses, or taxes) | Class I
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(14.58%)
5 Year	rr_AverageAnnualReturnYear05	1.65%
Since Inception	rr_AverageAnnualReturnSinceInception	0.67%	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2011
AMG GW&K Trilogy Emerging Markets Equity Fund | MSCI Emerging Markets Index (reflects no deduction for fees, expenses, or taxes) | Class Z
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(14.58%)
5 Year	rr_AverageAnnualReturnYear05	1.65%
Since Inception	rr_AverageAnnualReturnSinceInception	0.67%	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2011

[1] Class N and Index performance shown reflects performance since the inception date of the Fund’s Class N shares on March 1, 2012.

[2] Class I, Class Z and Index performance shown reflects performance since the inception date of the Fund’s Class I and Class Z shares on March 1, 2011.