Label

Element

Value

Risk/Return:

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Registrant Name

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PENN SERIES FUNDS INC

Prospectus Date

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May 01, 2015

Penn Series Large Core Value Fund

Risk/Return:

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Risk/Return [Heading]

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FUND SUMMARY:  LARGE CORE VALUE FUND

Objective [Heading]

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Investment Objective

Objective, Primary [Text Block]

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The investment objective of the Large Core Value Fund (the “Fund”) is to seek total return.

Expense [Heading]

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Fund Fees and Expenses

Expense Narrative [Text Block]

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This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. Additional fees and expenses will be applied at the variable contract level. Those fees and expenses are described in your variable contract prospectus. If the information below were to reflect the deduction of variable contract charges, fees and expenses would be higher.

Operating Expenses Caption [Text]

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Annual Fund Operating Expenses
(expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

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Portfolio Turnover

Portfolio Turnover [Text Block]

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The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in the 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 80% of the average value of its portfolio.

Portfolio Turnover, Rate

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80.00%

Expenses Restated to Reflect Current [Text]

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The expense information in the table has been restated to reflect an increase in the Fund's Investment Advisory Fee approved by Fund shareholders on February 13, 2014 and effective May 1, 2014.

Expense Example [Heading]

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Example

Expense Example Narrative [Text Block]

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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 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 and returns might be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

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Principal Investment Strategy

Strategy Narrative [Text Block]

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The Fund invests primarily in value stocks of large capitalization companies. Under normal circumstances, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in securities of large capitalization companies. For this Fund, large capitalization companies are those companies having market capitalizations equal to or greater than the median capitalization of companies included in the Russell 1000^® Value Index at the time of purchase (as of March 31, 2015, the median capitalization was $7.6 billion). Because the Fund’s definition of large capitalization companies is dynamic, it will change with the markets. Value stocks are stocks that, in the opinion of the Sub-Adviser, are inexpensive or undervalued relative to the overall stock market.

The Fund primarily invests in dividend-paying stocks, but may also invest in non-income producing stocks. The Fund may invest in real estate investment trusts (“REITs”). The Fund may invest up to 25% of its total assets in foreign securities, some of which may be located in emerging market countries. Securities of foreign issuers that are represented by American Depositary Receipts (“ADRs”) are not subject to this restriction.

The Sub-Adviser may consider a company’s earnings or cash flow capabilities, dividend prospects, financial strength, growth potential, the strength of the company’s business franchises and management team, sustainability of a company’s competitiveness, and estimates of a company’s net value when selecting securities. The Sub-Adviser may sell a security when the Sub-Adviser’s price objective for the security is reached, the fundamentals of the company deteriorate, a security’s price falls below acquisition cost or to pursue more attractive investment options.

The Fund may buy and sell portfolio securities actively. If it does, its portfolio turnover rate and transaction costs will rise, which may lower Fund performance.

Risk [Heading]

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Principal Risks of Investing

Risk Narrative [Text Block]

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Currency Risk.  The possibility that the value of the Fund’s assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies.

Depositary Receipt Risk.  The possibility that the Fund’s investments in foreign companies through depositary receipts will expose the Fund to the same risks as direct investment in securities of foreign issuers. In addition, investments in ADRs may be less liquid than the underlying shares in their primary trading market, and the value of securities underlying ADRs may change materially at times when U.S. markets are not open for trading.

Emerging Markets Risk.  The possibility that the stocks of companies located in emerging markets may be more volatile, and less liquid, than the stocks of companies located in the U.S. and developed foreign markets due to political, economic, or regulatory conditions within emerging market countries. In addition, emerging market countries may experience more volatile interest and currency exchange rates, higher levels of inflation and less efficient trading and settlement systems.

Foreign Investment Risk.  The possibility that the Fund’s investments in foreign securities may be adversely affected by political, social, and economic conditions affecting foreign issuers, greater volatility, reduced liquidity, or decreases in foreign currency values relative to the U.S. dollar.

Large-Cap Securities Risk.  The possibility that the Fund’s investments in larger companies may underperform relative to those of smaller companies. Larger more established companies may be unable to respond quickly to new competitive challenges such as changes in technology and consumer tastes and may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion.

Liquidity Risk.  The possibility that the market for certain of the Fund’s investments may become illiquid under adverse or volatile market or economic conditions, making those investments difficult to sell at an advantageous price. The market price of certain investments may fall dramatically if there is no liquid trading market for the investments. It also may be difficult for the Fund to purchase a desired investment at an advantageous price under such circumstances.

Management Risk.  The possibility that the investment decisions, techniques, analyses or models implemented by the Fund’s Sub-Adviser in seeking to achieve the Fund’s investment objective may not produce the returns expected, may cause the Fund’s shares to lose value or may cause the Fund to underperform relevant benchmarks or other funds with similar investment objectives.

Market Risk.  The possibility that the values of, and/or the income generated by, securities held by the Fund may decline, sometimes unpredictably, due to general market conditions or other factors, including those directly involving the issuers of such securities. Security markets are volatile and may decline significantly in response to adverse issuer, regulatory, political, or economic developments. Different sectors of the market and different security types may react differently to such developments.

Portfolio Turnover Risk.  The possibility that the Fund may frequently buy and sell portfolio securities, which may increase transaction costs to the Fund and cause the Fund’s performance to be less than you expect.

REITs Risk.  The possibility that the Fund’s investments in REITs will subject the Fund to the risks associated with the direct ownership of real estate, including fluctuations in the value of underlying properties, changes in interest rates and risks related to general or local economic conditions. REITs are dependent upon management skills and generally may not be diversified. REITs are also subject to heavy cash flow dependency, defaults by borrowers or tenants and self-liquidation.

“Value” Investing Risk.  The possibility that the Fund’s investments in securities believed by the Sub-Adviser to be undervalued may not realize their perceived value for extended periods of time or may never realize their perceived value. The securities in which the Fund invests may respond differently to market and other developments than other types of securities, and may underperform growth stocks and/or the market as a whole.

An investment in the Fund may be appropriate for investors who are willing to accept the risks and uncertainties of investing in common stocks in the hope of earning long-term growth of capital and income.

Bar Chart and Performance Table [Heading]

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Performance Information

Performance Narrative [Text Block]

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The bar chart and table below show the performance of the Fund both year-by-year and as an average over different periods of time. The bar chart and table demonstrate the variability of performance over time and provide an indication of the risks and volatility of an investment in the Fund by showing how the Fund’s average annual total returns for various periods compare with those of a broad-based securities market index. Past performance does not necessarily indicate how the Fund will perform in the future. This performance information does not include the impact of any charges deducted under your variable contract. If it did, returns would be lower.

Performance Information Illustrates Variability of Returns [Text]

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The bar chart and table below show the performance of the Fund both year-by-year and as an average over different periods of time. The bar chart and table demonstrate the variability of performance over time and provide an indication of the risks and volatility of an investment in the Fund by showing how the Fund’s average annual total returns for various periods compare with those of a broad-based securities market index.

Performance Past Does Not Indicate Future [Text]

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Past performance does not necessarily indicate how the Fund will perform in the future.

Bar Chart Does Not Reflect Sales Loads [Text]

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This performance information does not include the impact of any charges deducted under your variable contract. If it did, returns would be lower.

Bar Chart Closing [Text Block]

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Best Quarter	Worst Quarter
14.96%	-16.11%
9/30/2009	9/30/2011

Performance Table Heading

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Average Annual Total Return (for Periods Ended December 31, 2014)

Penn Series Large Core Value Fund | Large Core Value Fund

Risk/Return:

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Investment Advisory Fees

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0.67%

^[1]

Distribution (12b-1) Fees

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none

Other Expenses

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0.26%

Total Annual Fund Operating Expenses

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0.93%

^[1]

1 Year

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95

3 Years

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296

5 Years

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515

10 Years

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1,143

2009

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16.76%

2010

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10.44%

2011

rr_AnnualReturn2011

(4.19%)

2012

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15.58%

2013

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29.78%

2014

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11.29%

Highest Quarterly Return, Label

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Best Quarter

Highest Quarterly Return, Date

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Sep. 30, 2009

Highest Quarterly Return

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14.96%

Lowest Quarterly Return, Label

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Worst Quarter

Lowest Quarterly Return, Date

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Sep. 30, 2011

Lowest Quarterly Return

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(16.11%)

1 Year

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11.29%

5 Years

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12.05%

Since Inception

rr_AverageAnnualReturnSinceInception

6.64%

Inception Date

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Aug. 25, 2008

Penn Series Large Core Value Fund | Russell 1000® Value Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

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1 Year

rr_AverageAnnualReturnYear01

13.45%

5 Years

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15.42%

Since Inception

rr_AverageAnnualReturnSinceInception

9.43%

Inception Date

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Aug. 25, 2008

[1] The expense information in the table has been restated to reflect an increase in the Fund's Investment Advisory Fee approved by Fund shareholders on February 13, 2014 and effective May 1, 2014.