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 Moderate Allocation Fund

Risk/Return:

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Risk/Return [Heading]

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FUND SUMMARY:  MODERATE ALLOCATION FUND

Objective [Heading]

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Investment Objective

Objective, Primary [Text Block]

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The investment objective of the Moderate Allocation Fund (the “Fund”) is to seek to achieve long-term capital growth and current income consistent with its asset allocation strategy.

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 17% of the average value of its portfolio.

Portfolio Turnover, Rate

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17.00%

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.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

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The Total Annual Fund Operating Expenses in this fee table may not correlate to the expense ratios in the Fund's financial highlights and financial statements because the financial highlights and financial statements reflect only the operating expenses of the Fund and do not include Acquired Fund Fees and Expenses, which are fees and expenses incurred indirectly by the Fund through its investments in certain underlying investment companies.

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 seeks to achieve its investment objective by using a “fund-of-funds” strategy. Accordingly, the Fund invests in a combination of other Penn Series Funds (each, an “underlying fund” and, collectively, the “underlying funds”) in accordance with its target asset allocations. These underlying funds invest their assets directly in equity, fixed income, money market and other securities in accordance with their own investment objectives and policies. The underlying funds are managed using both indexed and active management strategies.

The Fund has its own distinct target portfolio allocation and is designed to accommodate specific investment goals and risk tolerances. Through its investments in the underlying funds, the Fund’s target allocation is intended to allocate the Fund’s assets among various asset classes, such as equity securities, fixed income securities and money market securities. The portfolio of the Fund is allocated among stock, bond and cash investments with a majority of its assets allocated to stocks, and is designed to offer investors an investment option that is less aggressive than the Penn Series Aggressive Allocation and Moderately Aggressive Allocation Funds, but more aggressive than the Penn Series Moderately Conservative Allocation and Conservative Allocation Funds.

In determining the asset allocation of the Fund, the Adviser will rely on the experience of its investment personnel and its evaluation of the overall financial markets, including, but not limited to, information about the economy, interest rates, and the long-term absolute and relative returns of various asset classes. Consideration will also be given to the investment styles of the managers of the underlying funds and their historic patterns of performance relative to their asset class and to other underlying funds. Periodic changes in allocations among the underlying funds will be based on information about the financial markets, changes within particular underlying funds, or the introduction of new Penn Series Funds that would, in the Adviser’s opinion, enhance the return potential of the Fund. These changes will be implemented as necessary, recognizing that these decisions tend to be long-term in nature, based on information about the financial markets and on the Fund’s investment objective.

The following chart shows the Fund’s target asset allocation among the various asset classes. The Adviser may permit modest deviations from the target asset allocations listed below. Accordingly, the Fund’s actual allocations may differ from this illustration.

Asset Class	Target Asset Allocation
Equity Funds	50% - 70%
Fixed Income and Money Market Funds	30% - 50%

The Adviser reserves the right to modify the Fund’s target asset allocations and to substitute other underlying funds and add additional underlying funds from time to time should circumstances warrant a change. The Adviser may periodically rebalance the Fund’s investments in the underlying funds to bring the Fund back within its target range.

Risk [Heading]

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Principal Risks

Risk Narrative [Text Block]

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Asset Allocation Risk.  The possibility that the Fund may underperform other funds with similar investment objectives due to the Fund’s allocation of assets to underlying funds investing in asset classes or market sectors that perform poorly relative to other asset categories.

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.

Underlying Fund Investment Risk.  The possibility that the underperformance of an underlying fund may contribute to the underperformance of the Fund. The Fund’s performance and risks will be directly related to the performance and risks of the underlying funds in which it invests. In addition, the Fund indirectly pays a pro rata portion of the expenses incurred by the underlying funds, which also may lower the Fund’s performance.

Corporate Debt Securities Risk.  The possibility that the issuer of a debt security held by an underlying fund is unable to meet its principal and interest payment obligations. The further possibility that corporate debt securities held by an underlying fund may experience increased price volatility due to such factors as market interest rates, market perception of the creditworthiness of the issuer and general market liquidity.

Credit Risk.  The possibility that an issuer of a debt security, or the counterparty to a derivatives contract, held by an underlying fund defaults on its payment obligations.

Derivatives Risk.  The possibility that an underlying fund’s use of derivatives, such as futures, options and swap agreements, may lead to losses, including those magnified by leverage, particularly when derivatives are used to enhance return rather than mitigate risk. Certain derivative instruments may be difficult to sell when the Adviser or Sub-Adviser of the underlying fund believes it would be appropriate to do so, difficult to value if the instrument becomes illiquid, or the other party to a derivative contract may be unwilling or unable to fulfill its contractual obligations.

Foreign Investment Risk.  The possibility that an underlying 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.

“Growth” Investing Risk.  The possibility that an underlying fund’s investments in securities of companies perceived to be “growth” companies may underperform when value investing is in favor and may be more volatile than other securities because they are more sensitive to investor perceptions of the issuing company’s growth of earnings potential. Also, because growth companies usually invest a high portion of earnings in their businesses, growth stocks may lack the dividends of some value stocks that can cushion stock prices in a falling market.

High Yield Bond Risk.  The possibility that an underlying fund’s investment in debt securities rated below investment grade (commonly known as junk bonds) may adversely affect the underlying fund’s yield. Although these securities generally provide for higher yields than higher rated debt securities, the high degree of risk associated with these investments can result in substantial or total loss to the underlying fund. High yield securities are considered speculative and are subject to a greater risk of loss, greater sensitivity to interest rate changes, increased price volatility, valuation difficulties, and a potential lack of a liquid secondary or public market for the securities.

Interest Rate Risk.  The possibility that the prices of an underlying fund’s fixed income investments will decline due to rising interest rates.

Investment Risk.  You may lose money by investing in the Money Market Fund. Although the Money Market Fund seeks to preserve the value of your investment at $1.00 per share, there is no guarantee that the Money Market Fund will be able to do so.

Large-Cap Securities Risk.  The possibility that an underlying 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 an underlying 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 an underlying fund to purchase a desired investment at an advantageous price under such circumstances.

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

Prepayment and Extension Risk.  The possibility that the principal on a fixed income security may be paid off earlier or later than expected causing an underlying fund to invest in fixed income securities with lower interest rates, which may adversely affect the underlying fund’s performance.

Small- and Mid-Cap Securities Risk.  The possibility that an underlying fund’s investments in small- and mid-cap securities may be subject to greater risk and higher volatility than are customarily associated with investing in larger more established companies. Securities issued by small- and mid-sized companies, which can include start-up companies, tend to be more vulnerable than larger and more established companies to adverse business and economic developments. Such companies generally have narrower product lines, more limited financial resources and more limited markets for their stock as compared with larger companies. As a result, the value of such securities also may be more volatile than the securities of larger companies, and an underlying fund’s portfolio may experience difficulty in purchasing or selling such securities at the desired time and price or in the desired amount.

U.S. Government Securities Risk.  The possibility that the U.S. government will not provide financial assistance in support of securities issued by certain of its agencies and instrumentalities and held by an underlying fund if it is not obligated to do because such securities are not issued or guaranteed by the U.S. Treasury. A default by a U.S. government agency or instrumentality could cause an underlying fund’s share price or yield to fall.

“Value” Investing Risk.  The possibility that an underlying fund’s investments in securities perceived 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 an underlying 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.

Risk Lose Money [Text]

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You may lose money by investing in the Money Market Fund.

Risk Money Market Fund [Text]

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Although the Money Market Fund seeks to preserve the value of your investment at $1.00 per share, there is no guarantee that the Money Market Fund will be able to do so.

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 and one additional index, the Barclays Capital U.S. Aggregate Bond Index. The Barclays Capital U.S. Aggregate Bond Index, in conjunction with the broad-based index, are used to track the broad range of allocations the Fund makes to the underlying funds. The foregoing indices, when considered together, may provide investors with a useful comparison of the Fund’s overall performance. 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 and one additional index, the Barclays Capital U.S. Aggregate Bond Index.

Performance Additional Market Index [Text]

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The Barclays Capital U.S. Aggregate Bond Index, in conjunction with the broad-based index, are used to track the broad range of allocations the Fund makes to the underlying funds. The foregoing indices, when considered together, may provide investors with a useful comparison of the Fund’s overall performance.

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
11.68%	-9.29%
6/30/2009	9/30/2011

Performance Table Heading

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

Penn Series Moderate Allocation Fund | Moderate Allocation Fund

Risk/Return:

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Investment Advisory Fees

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0.12%

^[1]

Distribution (12b-1) Fees

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none

Other Expenses

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0.20%

Acquired Fund Fees and Expenses

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0.83%

Total Annual Fund Operating Expenses

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1.15%

^[1],[2]

1 Year

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117

3 Years

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365

5 Years

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633

10 Years

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1,398

2009

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20.58%

2010

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12.24%

2011

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0.65%

2012

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10.93%

2013

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14.11%

2014

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5.63%

Highest Quarterly Return, Label

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Best Quarter

Highest Quarterly Return, Date

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Jun. 30, 2009

Highest Quarterly Return

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11.68%

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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(9.29%)

1 Year

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5.63%

5 Years

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8.60%

Since Inception

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6.35%

Inception Date

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Aug. 25, 2008

Penn Series Moderate Allocation Fund | Russell 3000® Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

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1 Year

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12.56%

5 Years

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15.63%

Since Inception

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10.14%

Inception Date

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Aug. 25, 2008

Penn Series Moderate Allocation Fund | Barclays Capital U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

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1 Year

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5.97%

5 Years

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4.45%

Since Inception

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5.03%

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.

[2] The Total Annual Fund Operating Expenses in this fee table may not correlate to the expense ratios in the Fund’s financial highlights and financial statements because the financial highlights and financial statements reflect only the operating expenses of the Fund and do not include Acquired Fund Fees and Expenses, which are fees and expenses incurred indirectly by the Fund through its investments in certain underlying investment companies.