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 27.91% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

27.91%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This 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 the period. 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

The Fund invests in the equity securities of companies located anywhere in the world, including developing markets. Under normal market conditions, the Fund invests at least 80% of its net assets in equity securities. The equity securities in which the Fund primarily invests are common stock. Under normal market conditions, the Fund will invest at least 40% of its net assets in foreign securities.

The Fund may invest in equity securities of any size company, across the entire market capitalization spectrum. The Fund may invest a substantial portion of its assets in smaller and midsize companies. From time to time, based on economic conditions, the Fund may have significant investments in one or more countries or in particular sectors such as financial institutions or industrial companies.

When choosing equity investments for the Fund, the investment manager applies a “bottom-up,” value-oriented, long-term approach, focusing on the market price of a company’s securities relative to the investment manager’s evaluation of the company’s long-term earnings, asset value and cash flow potential. The investment manager also considers a company’s price/earnings ratio, profit margins and liquidation value.

In selecting securities for the Fund, the investment manager attempts to identify those companies that offer above-average opportunities for capital appreciation in various countries and industries where economic and political factors, including currency movements, are favorable to capital growth.

The investment manager may consider selling an equity security when it believes the security has become overvalued due to either its price appreciation or changes in the company's fundamentals, or when the investment manager believes another security is a more attractive investment opportunity.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

Under normal market conditions, the Fund invests at least 80% of its net assets in equity securities.

Risk [Heading]

rr_RiskHeading

Principal Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. Mutual fund shares are not deposits or obligations of, or guaranteed or endorsed by, any bank, and are not insured by the Federal Deposit Insurance Corporation, the Federal Reserve Board, or any other agency of the U.S. government.

Market

The market values of securities or other investments owned by the Fund will go up or down, sometimes rapidly or unpredictably. The market value of a security or other investment may be reduced by market activity or other results of supply and demand unrelated to the issuer. This is a basic risk associated with all investments. When there are more sellers than buyers, prices tend to fall. Likewise, when there are more buyers than sellers, prices tend to rise.

Stock prices tend to go up and down more dramatically than those of debt securities. A slower-growth or recessionary economic environment could have an adverse effect on the prices of the various stocks held by the Fund.

Foreign Securities

Investing in foreign securities typically involves more risks than investing in U.S. securities, and includes risks associated with: (i) internal and external political and economic developments – e.g., the political, economic and social policies and structures of some foreign countries may be less stable and more volatile than those in the U.S. or some foreign countries may be subject to trading restrictions or economic sanctions; (ii) trading practices – e.g., government supervision and regulation of foreign securities and currency markets, trading systems and brokers may be less than in the U.S.; (iii) availability of information – e.g., foreign issuers may not be subject to the same disclosure, accounting and financial reporting standards and practices as U.S. issuers; (iv) limited markets – e.g., the securities of certain foreign issuers may be less liquid (harder to sell) and more volatile; and (v) currency exchange rate fluctuations and policies. The risks of foreign investments may be greater in developing or emerging market countries.

Regional Focus

Because the Fund may invest at least a significant portion of its assets in companies in a specific region, including Europe, the Fund is subject to greater risks of adverse developments in that region and/or the surrounding regions than a fund that is more broadly diversified geographically. Political, social or economic disruptions in the region, even in countries in which the Fund is not invested, may adversely affect the value of investments held by the Fund. Current political uncertainty surrounding the European Union (EU) and its membership, including the 2016 referendum in which the United Kingdom voted to exit the EU, may increase market volatility. The financial instability of some countries in the EU, including Greece, Italy and Spain, together with the risk of that impacting other more stable countries may increase the economic risk of investing in companies in Europe.

Developing Market Countries

The Fund’s investments in securities of issuers in developing market countries are subject to all of the risks of foreign investing generally, and have additional heightened risks due to a lack of established legal, political, business and social frameworks to support securities markets, including: delays in settling portfolio securities transactions; currency and capital controls; greater sensitivity to interest rate changes; pervasiveness of corruption and crime; currency exchange rate volatility; and inflation, deflation or currency devaluation.

Value Style Investing

A value stock may not increase in price as anticipated by the investment manager if other investors fail to recognize the company's value and bid up the price, the markets favor faster-growing companies, or the factors that the investment manager believes will increase the price of the security do not occur or do not have the anticipated effect.

Smaller and Midsize Companies

Securities issued by smaller and midsize companies may be more volatile in price than those of larger companies, involve substantial risks and should be considered speculative. Such risks may include greater sensitivity to economic conditions, less certain growth prospects, lack of depth of management and funds for growth and development, and limited or less developed product lines and markets. In addition, smaller and midsize companies may be particularly affected by interest rate increases, as they may find it more difficult to borrow money to continue or expand operations, or may have difficulty in repaying any loans.

Focus

To the extent that the Fund focuses on particular countries, regions, industries, sectors or types of investment from time to time, the Fund may be subject to greater risks of adverse developments in such areas of focus than a fund that invests in a wider variety of countries, regions, industries, sectors or investments.

Management

The Fund is subject to management risk because it is an actively managed investment portfolio. The Fund's investment manager applies investment techniques and risk analyses in making investment decisions for the Fund, but there can be no guarantee that these decisions will produce the desired results.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund's performance from year to year. The table shows how the Fund's average annual returns for 1 year, 5 years, 10 years or since inception, as applicable, compared with those of a broad measure of market performance. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. You can obtain updated performance information at ftinstitutional.com or by calling (800) 321-8563.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

(800) 321-8563

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

ftinstitutional.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

Annual Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best Quarter:	Q2'09	19.52%
Worst Quarter:	Q3'11	-17.07%
As of March 31, 2017, the Fund's year-to-date return was 6.70%.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns

For the periods ended December 31, 2016

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

The 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-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Templeton Institutional Funds-20 | Global Equity Series | Advisor Class

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases

rr_MaximumCumulativeSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.78%

Other expenses

rr_OtherExpensesOverAssets

0.06%