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 7% of the average value of its portfolio.

Expense Example, Narrative

rr_ExpenseExampleNarrativeTextBlock

Example: 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 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. The example does not reflect expenses that apply to separate accounts or related annuity contracts, and if such expenses were reflected, fees would be higher. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy, Narrative

rr_StrategyNarrativeTextBlock

The Fund operates under a fund of funds structure. The Fund invests substantially all of its assets in the Income Fund, the Large Company Growth Portfolio, the Large Company Value Portfolio, the Small Company Growth Portfolio, the Small Company Value Portfolio and the Wilshire International Equity Fund. As a matter of investment policy, the Fund expects to invest 20% to 50% of its assets in the Income Fund, 0% to 50% in the Large Company Value Portfolio, 0% to 50% in the Large Company Growth Portfolio, 0 to 20% in the Small Company Value Portfolio, 0% to 20% in the Small Company Growth Portfolio, and 0% to 30% in the Wilshire International Equity Fund. Under normal circumstances, the Fund’s target asset mix is 65% equity securities and 35% fixed income securities, with a range of 50% to 80% in equity securities and a range of 20% to 50% in fixed income securities. In addition, the Fund may invest in certain individual securities, including money market instruments and U.S. government securities.

The following describes the types of securities in which the Income Fund is permitted to invest:

The Income Fund invests, under normal circumstances, at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in fixed income securities. These securities are primarily investment grade fixed income securities, including government and corporate securities, mortgage- and asset-backed securities, which are generally pass through securities, and may also include related derivatives.

The Income Fund invests at least 75% of its total assets in:

• investment grade, publicly offered debt securities, including mortgage-backed and other asset-backed securities (within the four highest ratings as determined by Moody’s Investors Service (“Moody’s”), Standard & Poor’s (“S&P”) or an equivalent rating at the time of purchase)

• securities issued or guaranteed by the U.S. government or its agencies, including obligations issued or guaranteed by U.S., local, city and state government and agencies

• high quality commercial paper (within the two highest grades as determined by both Moody’s and S&P or an equivalent rating), certificates of deposit, bankers’ acceptances, repurchase and reverse repurchase agreements, time deposits with maturities less than seven days and cash or cash equivalents

• high grade U.S. dollar-denominated debt obligations of foreign governments, foreign corporations, foreign branches of U.S. banks and foreign banks (limited to the four highest ratings as determined by Moody’s, S&P or an equivalent rating at the time of purchase and to 15% of the Income Fund’s total assets)

• highest quality non U.S. dollar-denominated debt obligations of foreign issuers (limited to the four highest ratings as determined by Moody’s, S&P or an equivalent rating at the time of purchase) and do not exceed 20% of the Income Fund’s total assets and up to 10% of the Income Fund’s total assets may be invested in non-U.S. denominated investments via foreign currency transactions and unhedged foreign currency denominated bonds.

Generally, the average duration of the U.S. portion of the Income Fund will range within 25% of the Barclays Capital U.S. Aggregate Bond Index’s duration. There are no maximum maturity limits on individual securities. For defensive purposes, the duration and maturity of the Income Fund may be shortened. The Income Fund will maintain a high grade average quality for the portfolio (third highest rating as determined by Moody’s, S&P or an equivalent rating).

Up to 25% of the Income Fund’s total assets may be invested in securities not described above, including preferred stock, convertible securities, securities carrying warrants to purchase equity securities, U.S. dollar denominated and non-U.S. dollar denominated debt obligations of U.S. and non-U.S. issuers, including emerging market issuers, rated below BBB (by Moody’s, S&P or an equivalent rating) and non U.S. debt obligations rated below the highest quality (as determined by Moody’s, S&P or an equivalent rating) and derivatives.

The following describes the types of securities in which the Large Company Growth Portfolio is permitted to invest:

• The Large Company Growth Portfolio focuses on the large company growth segment of the U.S. equity market.

• The Large Company Growth Portfolio invests substantially all of its assets in common stock of companies with large market capitalizations—generally greater than $10 billion at the time of purchase.

• The Large Company Growth Portfolio invests in companies that historically have above average earnings or sales growth and retention of earnings, often such companies have above average price to earnings ratios.

• The Large Company Growth Portfolio uses a multi-manager strategy with multiple subadvisers who employ different strategies.

The following describes the types of securities in which the Large Company Value Portfolio is permitted to invest:

• The Large Company Value Portfolio focuses on the large company value segment of the U.S. equity market.

• The Large Company Value Portfolio invests substantially all of its assets in the common stock companies with large market capitalizations—generally greater than $10 billion at the time of purchase.

• The Large Company Value Portfolio invests, generally, in companies with relatively low price to book value ratios, low price to earnings ratios and higher than average dividend yields (which means that their prices are low relative to the size of their dividends).

• The Large Company Value Portfolio uses a multi-manager strategy with multiple subadvisers who employ different strategies.

The following describes the types of securities in which the Small Company Growth Portfolio is permitted to invest:

• The Small Company Growth Portfolio focuses on the small company growth segment of the U.S. equity market.

• The Small Company Growth Portfolio invests substantially all of its assets in the common stock of companies with smaller market capitalizations—which is generally less than $3 billion at the time of purchase.

• The Small Company Growth Portfolio invests in companies that historically have above average earnings or sales growth and retention of earnings, often such companies have above average price to earnings ratios.

• The Small Company Growth Portfolio invests in small-cap companies that may still further develop.

• The Small Company Growth Portfolio uses a multi-manager strategy with multiple subadvisers who employ different strategies.

The following describes the types of securities in which the Small Company Value Portfolio is permitted to invest:

• The Small Company Value Portfolio focuses on the small company value segment of the U.S. equity market.

• The Small Company Value Portfolio invests substantially all of its assets in the common stock of companies with smaller market capitalizations—which is generally less than $3 billion at the time of purchase.

• The Small Company Value Portfolio invests, generally, in companies with relatively low price to book value ratios, low price to earnings ratios and relatively high dividend yields.

• The Small Company Value Portfolio invests in small-cap companies that may still further develop.

• The Small Company Value Portfolio uses a multi-manager strategy with multiple subadvisers who employ different strategies.

The following describes the types of securities in which the Wilshire International Equity Fund is permitted to invest:

The Wilshire International Equity Fund invests, under normal circumstances, at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities. The Wilshire International Equity Fund invests in companies organized outside the United States. Since the Wilshire International Equity Fund invests in companies of any size, it may at times invest in small-cap companies. The Wilshire International Equity Fund intends to diversify investments among several countries and to have represented in its holdings business activities in not less than three different countries. The Wilshire International Equity Fund invests primarily in equity securities of established companies that the subadvisers believe have favorable characteristics and that are listed on foreign exchanges. The Wilshire International Equity Fund may invest up to 35% of its net assets in emerging market securities, including ETFs. The Wilshire International Equity Fund may also invest in fixed-income securities of foreign governments and companies. The Wilshire International Equity Fund uses a multi-manager strategy with subadvisers who may employ different strategies.

Risk, Narrative

rr_RiskNarrativeTextBlock

You may lose money by investing in the Fund. By investing in the Fund, an investor also assumes the same types of risks, either directly, or indirectly, as investing in the Income Fund, the Large Company Growth Portfolio, the Large Company Value Portfolio, the Small Company Growth Portfolio, the Small Company Value Portfolio and the Wilshire International Equity Fund. Investing in the Fund involves the following principal risks:

Asset Allocation Risk. Although asset allocation among different asset categories and investment strategies generally reduces risk and exposure to any one category or strategy, the risk remains that the Adviser may favor an asset category or investment strategy that performs poorly relative to other asset categories and investment strategies.

Equity Risk. The principal risk of investing in the Large Company Growth Portfolio, the Large Company Value Portfolio, the Small Company Growth Portfolio, the Small Company Value Portfolio and the Wilshire International Equity Fund is equity risk. This is the risk that the prices of stocks held by the Fund will change due to general market and economic conditions, perceptions regarding the industries in which the companies participate, and each company’s particular circumstances. Equity investments, including common stocks, tend to be more volatile than bonds and money market instruments. The value of the Fund’s shares will go up and down due to movement in the collective returns of the individual securities held by Fund. Because common stocks are subordinate to preferred stocks in a company’s capital structure, in a company liquidation, the claims of secured and unsecured creditors and owners of bonds and preferred stocks take precedence over the claims of common stock shareholders.

Credit Risk. For debt securities, credit risk is the possibility that an issuer or counterparty to a contract will fail to make timely payments of interest or principal to a fund. The credit risk of the Income Fund depends on the credit quality of its underlying securities. In general, for debt securities, the lower the credit quality of a fund’s securities, the higher a fund’s risk, all other factors such as maturity being equal.

Interest Rate Risk. For debt securities, interest rate risk is the possibility that the price will fall because of changing interest rates. In general, debt securities’ prices rise or fall inversely to changes in interest rates. If interest rates rise, bond prices generally fall; if interest rates fall, bond prices generally rise. In addition, for a given change in interest rates, longer-maturity bonds fluctuate more in price (gaining or losing more in value) than shorter-maturity bonds.

Prepayment Risk. Mortgage-backed securities are subject to the risk of unanticipated prepayments of principal with respect to mortgages in the security’s underlying pool of assets. While principal prepayments are passed through to the holders of the securities, prepayments also reduce the future payments on such securities and may reduce their value. Mortgage-backed securities are subject to the risk that an unexpected rise in interest rates will extend the life of a mortgage-backed security beyond the expected prepayment time, typically reducing the security’s value. Mortgage-backed securities are subject to the risk that an unexpected decline in interest rates will contract the life of a mortgage-backed security, thereby affecting its prepayment schedule, which may affect the value of the security.

Reinvestment Risk. During periods of falling interest rates, a debt security with a high stated interest rate may be prepaid (or “called”) prior to its expected maturity date. If, during periods of falling interest rates, a debt security with a high stated interest rate is called, the unanticipated proceeds would likely be invested at lower interest rates, and a fund’s income or yield may decline. Call provisions, which may lead to reinvestment risk, are most common for intermediate- and long-term municipal, corporate and mortgage-backed securities. To the extent securities subject to call were acquired at a premium, the potential for appreciation in the event of a decline in interest rates may be limited and may even result in losses.

Recent Market Events Risk. The equity and debt capital markets in the U.S. and elsewhere have experienced unprecedented volatility in the past several years. This financial crisis had caused a significant decline in the value and liquidity of many securities and may create a higher degree of volatility in the net asset values of many mutual funds, including the Fund. Because these events are unprecedented, it is difficult to predict their magnitude or duration. Changes in market conditions will not have the same impact on all types of securities.

In response to the crisis, the U.S. Government and the Federal Reserve have taken steps to support financial markets. The withdrawal of this support could negatively impact the value and liquidity of certain securities. In addition, legislation recently enacted in the U.S. calls for changes in many aspects of financial regulation. The impact of the legislation on the markets, and the practical implications for market participants, may not be fully known for some time.

Portfolio Turnover Risk. A fund that trades aggressively will experience high portfolio turnover and relatively high brokerage and other transaction costs. Such transaction costs may lower a fund’s effective investment return.

Portfolio Strategy Risk. The investment performance of the Income Fund is in part dependent upon a subadviser’s skill in making appropriate investments. To the extent that a fund’s investments differ from the portfolio represented by the benchmark, there exists the potential for volatility of the return of a fund relative to its index. As the industry and sector composition of the market or index changes over time, the implementation of a fund’s strategy can lead to substantial differences in the sector or industry allocation of a fund relative to the market or index.

Liquidity Risk. The Income Fund may invest in certain securities that may be difficult or impossible to sell at a certain time and at a price that the Fund finds to be favorable. The Income Fund may have to accept an unfavorable price, sell other securities instead or forego an investment opportunity, any of which could have a negative effect on portfolio management or investment performance.

Currency Risk. Non U.S. dollar-denominated securities are subject to fluctuations in the exchange rates between the U.S. dollar and foreign currencies which may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign currency denominated investments, and may widen any losses.

Derivatives Risk. When a fund uses derivatives (securities whose value is based upon the value of another security or an index) to hedge positions in the portfolio, any loss generated by the derivative security should be substantially offset by gains on the hedged investment and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. To the extent that a derivative is not used as a hedge (i.e., for speculation), a fund is directly exposed to the potential gains and losses of that derivative. Gains and losses from non hedging derivative positions may be substantially greater than the derivative’s original cost. To the extent a fund uses derivatives, a fund will (to the extent required by applicable law) either segregate cash or liquid assets in the prescribed amounts or “cover” its future obligations under the transaction, such as by holding an offsetting investment.

Valuation Risk. A fund may invest in securities that are difficult to value and may inadvertently value certain of its securities at a higher price than the market will bear.

Foreign Investment Risk. Foreign investments often involve risks such as political instability, differences in financial reporting standards and less stringent regulation of securities markets. These risks are magnified in less-established, emerging markets.

Style Risk. The risk of investing in the Large Company Growth Portfolio, the Large Company Value Portfolio, the Small Company Growth Portfolio and the Small Company Value Portfolio is the risk that the portfolios’ growth or value styles will perform poorly or fall out of favor with investors. For example, at times the market may favor large capitalization stocks over small capitalization stocks, value stocks over growth stocks, or vice versa.

Multi-Managed Fund Risk. The Income Fund, the Large Company Growth Portfolio, the Large Company Value Portfolio, the Small Company Growth Portfolio, the Small Company Value Portfolio and the Wilshire International Equity Fund are multi-managed funds with multiple subadvisers who employ different strategies. As a result, the Income Fund, the Large Company Growth Portfolio, the Large Company Value Portfolio, the Small Company Growth Portfolio, the Small Company Value Portfolio and the Wilshire International Equity Fund may have buy and sell transactions in the same security on the same day.

ETF Risk. ETFs in which the Wilshire International Equity Fund may invest involve certain inherent risks generally associated with investments in a portfolio of common stocks, including the risk that the general level of stock prices may decline, thereby adversely affecting the value of each unit of the ETF. Moreover, an ETF may not fully replicate the performance of its benchmark index because of the temporary unavailability of certain index securities in the secondary market or discrepancies between the ETF and the index with respect to the weighting of securities or the number of stocks held. Investing in ETFs, which are investment companies, involves duplication of advisory fees and certain other expenses.

Emerging Market Risk. Foreign investment risk may be particularly high to the extent the Wilshire International Equity Fund invests in securities of issuers based in countries with developing economies (i.e., emerging markets). These securities may present market, credit, currency, liquidity, legal, political and other risks different from, or greater than, the risks of investing in developed foreign (non-U.S.) countries.

Small Cap Risk. Small-cap companies may lack the management experience, financial resources, product diversity and competitive strengths of larger companies, and may be traded less frequently. These companies may be in the developmental stage or may be older companies undergoing significant changes. Small-cap companies may also be subject to greater business risks and more sensitive to changes in economic conditions than larger more established companies. As a result, the prices of small-cap companies may rise and fall more sharply than larger capitalized companies.

Large-Cap Company Risk. Larger, more established companies may be unable to attain the high growth rates of successful, smaller companies during periods of economic expansion.

Market Risk. For equity securities, stock market movements will affect the Large Company Growth Portfolio, the Large Company Value Portfolio, the Small Company Growth Portfolio, the Small Company Value Portfolio and the Wilshire International Equity Fund’s share price on a daily basis. Declines in value are possible because of declines in the stock market in general or because of a decline in the specific securities held by the Large Company Growth Portfolio, the Large Company Value Portfolio, the Small Company Growth Portfolio, the Small Company Value Portfolio and the Wilshire International Equity Fund. There is also the possibility that the price of the security will fall because the market perceives that there is or will be a deterioration in the fundamental value of the issuer or poor earnings performance by the issuer. Market risk may affect a single company, industry, sector or the market as a whole. For debt securities, the market value of a security may move up and down, sometimes rapidly and unpredictably. Market risk may affect a single issuer, an industry, a sector or the bond market as a whole.

Bar Chart and Performance Table, Heading

rr_BarChartAndPerformanceTableHeading

Performance

Performance, Information Illustrates Variability of Returns

rr_PerformanceInformationIllustratesVariabilityOfReturns

The information below provides an illustration of how the Fund’s performance has varied over time.

Bar Chart, Heading

rr_BarChartHeading

Calendar Year Returns

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return for a quarter

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

11.23%

Lowest Quarterly Return Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Performance Table:

rr_PerformanceTableHeading

Average Annual Total Returns
(periods ended December 31, 2012)

Risk/Return:

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

1.66%

1 Year

rr_AverageAnnualReturnYear01

4.21%

10 Years

rr_AverageAnnualReturnYear10

5.18%

Risk/Return:

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

(3.69%)

1 Year

rr_AverageAnnualReturnYear01

12.17%

^[1]

10 Years

rr_AverageAnnualReturnYear10

6.93%

^[1]

Risk/Return:

rr_RiskReturnAbstract

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.16%

^[2]

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

1.15%

^[2]

Expense Example, 1 YEAR

rr_ExpenseExampleYear01

$ 153

Expense Example, 5 YEARS

rr_ExpenseExampleYear05

818

2003

rr_AnnualReturn2003

19.55%

2005

rr_AnnualReturn2005

4.29%

2007

rr_AnnualReturn2007

3.08%

2009

rr_AnnualReturn2009

18.03%

2011

rr_AnnualReturn2011

(0.65%)

1 Year

rr_AverageAnnualReturnYear01

12.11%

10 Years

rr_AverageAnnualReturnYear10

5.19%

Risk/Return:

rr_RiskReturnAbstract

Investment objective:

rr_ObjectiveHeading

Investment Objective

Fees and expenses of the fund:

rr_ExpenseHeading

Fees and Expenses of the Fund

Annual fund operating expenses, heading

rr_OperatingExpensesCaption

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

Portfolio turnover, narrative

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 307% of the average value of its portfolio.

Expense Example, Narrative

rr_ExpenseExampleNarrativeTextBlock

Example: 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 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. The example does not reflect expenses that apply to separate accounts or related annuity contracts, and if such expenses were reflected, fees would be higher. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy, Narrative

rr_StrategyNarrativeTextBlock

The Fund invests, under normal circumstances, at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in fixed income securities. These securities are primarily investment grade fixed income securities, including government and corporate securities, mortgage- and asset-backed securities, which are generally pass through securities, and may also include related derivatives.

The Fund invests at least 75% of its total assets in:

• investment grade, publicly offered debt securities, including mortgage-backed and other asset-backed securities (within the four highest ratings as determined by Moody’s Investors Service (“Moody’s”), Standard & Poor’s (“S&P”) or an equivalent rating at the time of purchase)

• securities issued or guaranteed by the U.S. government or its agencies, including obligations issued or guaranteed by U.S., local, city and state government and agencies

• high quality commercial paper (within the two highest grades as determined by both Moody’s and S&P or an equivalent rating), certificates of deposit, bankers’ acceptances, repurchase and reverse repurchase agreements, time deposits with maturities less than seven days and cash or cash equivalents

• high grade U.S. dollar-denominated debt obligations of foreign governments, foreign corporations, foreign branches of U.S. banks and foreign banks (limited to the four highest ratings as determined by Moody’s, S&P or an equivalent rating at the time of purchase and to 15% of the Fund’s total assets)

• highest quality non U.S. dollar-denominated debt obligations of foreign issuers (limited to the four highest ratings as determined by Moody’s, S&P or an equivalent rating at the time of purchase) and do not exceed 20% of the Income Fund’s total assets and up to 10% of the Income Fund’s total assets may be invested in non-U.S. denominated investments via foreign currency transactions and unhedged foreign currency denominated bonds.

Generally, the average duration of the U.S. portion of the Fund will range within 25% of the Barclays Capital Aggregate Bond Index’s duration. There are no maximum maturity limits on individual securities. For defensive purposes, the duration and maturity of the Income Fund may be shortened. The Fund will maintain a high grade average quality for the portfolio (third highest rating as determined by Moody’s, S&P or an equivalent rating).

Up to 25% of the Fund’s total assets may be invested in securities not described above, including preferred stock, convertible securities, securities carrying warrants to purchase equity securities, U.S. dollar denominated and non-U.S. dollar denominated debt obligations of U.S. and non-U.S. issuers, including emerging market issuers, rated below BBB (by Moody’s, S&P or an equivalent rating) and non-U.S. debt obligations rated below the highest quality (as determined by Moody’s, S&P or an equivalent rating) and derivatives.

Risk, Narrative

rr_RiskNarrativeTextBlock

You may lose money by investing in the Fund. In addition, investing in the Fund involves the following principal risks:

Credit Risk. For debt securities, credit risk is the possibility that an issuer or counterparty to a contract will fail to make timely payments of interest or principal to a fund. The credit risk of the Fund depends on the credit quality of its underlying securities. In general, for debt securities, the lower the credit quality of a fund’s securities, the higher a fund’s risk, all other factors such as maturity being equal.

Interest Rate Risk. For debt securities, interest rate risk is the possibility that the price will fall because of changing interest rates. In general, debt securities’ prices rise or fall inversely to changes in interest rates. If interest rates rise, bond prices generally fall; if interest rates fall, bond prices generally rise. In addition, for a given change in interest rates, longer-maturity bonds fluctuate more in price (gaining or losing more in value) than shorter-maturity bonds.

Prepayment Risk. Mortgage-backed securities are subject to the risk of unanticipated prepayments of principal with respect to mortgages in the security’s underlying pool of assets. While principal prepayments are passed through to the holders of the securities, prepayments also reduce the future payments on such securities and may reduce their value. Mortgage-backed securities are subject to the risk that an unexpected rise in interest rates will extend the life of a mortgage-backed security beyond the expected prepayment time, typically reducing the security’s value. Mortgage-backed securities are subject to the risk that an unexpected decline in interest rates will contract the life of a mortgage-backed security, thereby affecting its prepayment schedule, which may affect the value of the security.

Reinvestment Risk. During periods of falling interest rates, a debt security with a high stated interest rate may be prepaid (or “called”) prior to its expected maturity date. If, during periods of falling interest rates, a debt security with a high stated interest rate is called, the unanticipated proceeds would likely be invested at lower interest rates, and a fund’s income or yield may decline. Call provisions, which may lead to reinvestment risk, are most common for intermediate- and long-term municipal, corporate and mortgage-backed securities. To the extent securities subject to call were acquired at a premium, the potential for appreciation in the event of a decline in interest rates may be limited and may even result in losses.

Portfolio Turnover Risk. A fund that trades aggressively will experience high portfolio turnover and relatively high brokerage and other transaction costs. Such transaction costs may lower a fund’s effective investment return.

Portfolio Strategy Risk. The investment performance of the Fund is in part dependent upon a subadviser’s skill in making appropriate investments. To the extent that a fund’s investments differ from the portfolio represented by the benchmark, there exists the potential for volatility of the return of a fund relative to its index. As the industry and sector composition of the market or index changes over time, the implementation of a fund’s strategy can lead to substantial differences in the sector or industry allocation of a fund relative to the market or index.

Liquidity Risk. The Fund may invest in certain securities that may be difficult or impossible to sell at a certain time and at a price that the Fund finds to be favorable. The Fund may have to accept an unfavorable price, sell other securities instead or forego an investment opportunity, any of which could have a negative effect on portfolio management or investment performance.

Currency Risk. Non U.S. dollar-denominated securities are subject to fluctuations in the exchange rates between the U.S. dollar and foreign currencies which may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign currency denominated investments, and may widen any losses.

Derivatives Risk. When a fund uses derivatives (securities whose value is based upon the value of another security or an index) to hedge positions in the portfolio, any loss generated by the derivative security should be substantially offset by gains on the hedged investment and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. To the extent that a derivative is not used as a hedge (i.e., for speculation), a fund is directly exposed to the potential gains and losses of that derivative. Gains and losses from non hedging derivative positions may be substantially greater than the derivative’s original cost. To the extent a fund uses derivatives, a fund will (to the extent required by applicable law) either segregate cash or liquid assets in the prescribed amounts or “cover” its future obligations under the transaction, such as by holding an offsetting investment.

Valuation Risk. A fund may invest in securities that are difficult to value and may inadvertently value certain of its securities at a higher price than the market will bear.

Foreign Investment Risk. Foreign investments often involve risks such as political instability, differences in financial reporting standards and less stringent regulation of securities markets. These risks are magnified in less-established, emerging markets.

Recent Market Events Risk. The equity and debt capital markets in the U.S. and elsewhere have experienced unprecedented volatility in the past several years. This financial crisis had caused a significant decline in the value and liquidity of many securities and may create a higher degree of volatility in the net asset values of many mutual funds, including the Fund. Because these events are unprecedented, it is difficult to predict their magnitude or duration. Changes in market conditions will not have the same impact on all types of securities.

In response to the crisis, the U.S. Government and the Federal Reserve have taken steps to support financial markets. The withdrawal of this support could negatively impact the value and liquidity of certain securities. In addition, legislation recently enacted in the U.S. calls for changes in many aspects of financial regulation. The impact of the legislation on the markets, and the practical implications for market participants, may not be fully known for some time.

Certain Wilshire funds are permitted to invest in the Fund. As a result, the Fund may have large inflows or outflows of cash from time to time. This could have adverse effects on the Fund’s performance if the Fund were required to sell securities or invest cash at times when it otherwise would not do so. This activity could also accelerate the realization of capital gains and increase the Fund’s transaction costs.

Bar Chart and Performance Table, Heading

rr_BarChartAndPerformanceTableHeading

Performance

Performance, Information Illustrates Variability of Returns

rr_PerformanceInformationIllustratesVariabilityOfReturns

The information below provides an illustration of how the Fund’s performance has varied over time.

Bar Chart, Heading

rr_BarChartHeading

Calendar Year Returns

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest return for a quarter

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

6.35%

Lowest Quarterly Return Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2008

Performance Table:

rr_PerformanceTableHeading

Average Annual Total Returns

(periods ended December 31, 2012)

Risk/Return:

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

5.95%

Management Fees

rr_ManagementFeesOverAssets

0.55%

Other Expenses

rr_OtherExpensesOverAssets

0.34%

Expense Example, 1 YEAR

rr_ExpenseExampleYear01

116

Expense Example, 5 YEARS

rr_ExpenseExampleYear05

628

2003

rr_AnnualReturn2003

7.35%

2005

rr_AnnualReturn2005

1.97%

2007

rr_AnnualReturn2007

4.21%

2009

rr_AnnualReturn2009

13.29%

2011

rr_AnnualReturn2011

6.92%

1 Year

rr_AverageAnnualReturnYear01

7.31%

10 Years

rr_AverageAnnualReturnYear10

5.15%

Risk/Return:

rr_RiskReturnAbstract

Investment objective:

rr_ObjectiveHeading

Investment Objective

Fees and expenses of the fund:

rr_ExpenseHeading

Fees and Expenses of the Fund

Annual fund operating expenses, heading

rr_OperatingExpensesCaption

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

Portfolio turnover, heading

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover Rate

rr_PortfolioTurnoverRate

100.00%

Strategy, Heading

rr_StrategyHeading

Principal Investment Strategies

Risk, Heading

rr_RiskHeading

Principal Risks

May Lose Money

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Performance, Narrative

rr_PerformanceNarrativeTextBlock

The information below provides an illustration of how the Fund’s performance has varied over time. The bar chart and table provide some indication of the risks of investing in the Fund by showing the changes in the Fund’s investment performance from year to year during the periods indicated and by showing how the average annual total returns for the one-, five- and ten-year periods compare with a broad-based securities market index. The total return figures do not reflect expenses that apply to the separate account or related annuity contracts. The inclusion of these charges would reduce the total return figures for all periods shown. The Fund’s past investment performance does not necessarily indicate how it will perform in the future.

Performance, Past Does Not Indicate Future

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The Fund’s past investment performance does not necessarily indicate how it will perform in the future.

Bar Chart, Closing

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During the periods shown in the bar chart, the highest return for a quarter was 29.55% (quarter ended 6/30/03) and the lowest return for a quarter was -27.01% (quarter ended 12/31/08).

Highest Quarterly Return Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Lowest Quarterly Return, Label

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lowest return for a quarter

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(27.01%)

Performance Table Market Index Changed

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Effective April 2, 2013, the Fund changed its benchmark to the Russell 2000® Index because it is more reflective of the Fund’s investment strategy.

Risk/Return:

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5 Years

rr_AverageAnnualReturnYear05

3.56%

^[3]

1 Year

rr_AverageAnnualReturnYear01

14.59%

10 Years

rr_AverageAnnualReturnYear10

9.80%

Risk/Return:

rr_RiskReturnAbstract

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

^[4]

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.83%

^[4]

Less Fee Waivers

rr_FeeWaiverOrReimbursementOverAssets

(0.07%)

^[4],[5]

Expense Example, 1 YEAR

rr_ExpenseExampleYear01

171

Expense Example, 5 YEARS

rr_ExpenseExampleYear05

925

2003

rr_AnnualReturn2003

59.16%

2005

rr_AnnualReturn2005

3.65%

2007

rr_AnnualReturn2007

13.90%

2009

rr_AnnualReturn2009

28.39%

2011

rr_AnnualReturn2011

(0.64%)

1 Year

rr_AverageAnnualReturnYear01

6.85%

10 Years

rr_AverageAnnualReturnYear10

7.27%

Risk/Return:

rr_RiskReturnAbstract

Investment objective:

rr_ObjectiveHeading

Investment Objective

Fees and expenses of the fund:

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Fees and Expenses of the Fund

Annual fund operating expenses, heading

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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

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover Rate

rr_PortfolioTurnoverRate

27.00%

Strategy, Heading

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Principal Investment Strategies

Risk, Heading

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Principal Risks

May Lose Money

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You may lose money by investing in the Fund.

Performance, Narrative

rr_PerformanceNarrativeTextBlock

The information below provides an illustration of how the Fund’s performance has varied over time. The bar chart and table provide some indication of the risks of investing in the Fund by showing the changes in the Fund’s investment performance from year to year during the periods indicated and by showing how the average annual total returns for the one-, five- and ten-year periods compare with a broad-based securities market index. The total return figures do not reflect expenses that apply to the separate account or related annuity contracts. The inclusion of these charges would reduce the total return figures for all periods shown. The Fund’s past investment performance does not necessarily indicate how it will perform in the future.

Performance, Past Does Not Indicate Future

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past investment performance does not necessarily indicate how it will perform in the future.

Bar Chart, Closing

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During the periods shown in the bar chart, the highest return for a quarter was 24.58% (quarter ended 6/30/09) and the lowest return for a quarter was -21.43% (quarter ended 9/30/11).

Highest Quarterly Return Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return for a quarter

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(21.43%)