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 47% of the average value of its portfolio.

Example, heading

rr_ExpenseExampleHeading

* Estimated based on expected allocation as of April 2, 2013. The Fund’s shareholders indirectly bear, pro rata, the expenses of the Fund’s assets invested in the Large Company Growth Portfolio and the Large Company Value Portfolio. These indirect expenses are based on actual expense ratios for the Large Company Growth Portfolio and the Large Company Value Portfolio. The Management Fee charged to the Fund (0.70%) is based on the average daily net assets of the Fund that are not invested in the Large Company Growth Portfolio and the Large Company Value Portfolio. Accordingly, the Management Fee shown in the table is based on the Fund’s target allocation of 33% of assets invested in the Large Company Growth Portfolio and 33% of assets invested in the Large Company Value Portfolio. The Fund’s investments in the Large Company Growth Portfolio and the Large Company Value Portfolio are not reflected in the Fund’s expense ratio as shown in the Financial Highlights table of this Prospectus.

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

rr_PerformancePastDoesNotIndicateFuture

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

Bar Chart, Closing

rr_BarChartClosingTextBlock

During the periods shown in the bar chart, the highest return for a quarter was 15.72% (quarter ended 06/30/03) and the lowest return for a quarter was -22.46% (quarter ended 12/31/08).

Highest Quarterly Return Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest return for a quarter

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(22.46%)

1 Year

rr_AverageAnnualReturnYear01

16.00%

10 Years

rr_AverageAnnualReturnYear10

7.10%

Risk/Return:

rr_RiskReturnAbstract

Management Fees

rr_ManagementFeesOverAssets

0.24%

Other Expenses

rr_OtherExpensesOverAssets

0.23%

Total Annual Fund Operating Expenses

rr_NetExpensesOverAssets

1.46%

Expense Example, 3 YEARS

rr_ExpenseExampleYear03

462

Expense Example, 10 YEARS

rr_ExpenseExampleYear10

1,746

2004

rr_AnnualReturn2004

10.15%

2006

rr_AnnualReturn2006

16.92%

2008

rr_AnnualReturn2008

(40.19%)

2010

rr_AnnualReturn2010

11.58%

2012

rr_AnnualReturn2012

14.66%

5 Years

rr_AverageAnnualReturnYear05

(1.69%)

Risk/Return

rr_RiskReturnHeading

Balanced Fund

Investment objective

rr_ObjectivePrimaryTextBlock

The Balanced Fund (the “Fund”) seeks to realize a high long-term total rate of return consistent with prudent investment risks. Total rate of return consists of current income, which includes dividends, interest, discount accruals and capital appreciation.

Fees and expenses of the fund, narrative

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. The table below does not reflect expenses that apply to separate accounts or related annuity contracts, and if such expenses were reflected, fees would be higher.

Portfolio turnover, heading

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover Rate

rr_PortfolioTurnoverRate

7.00%

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 U.S. investment grade fixed income securities, including government and corporate securities, mortgage and asset-backed securities, which are generally pass through securities.

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

• high quality commercial paper (within the two highest grades as determined by both Moody’s and S&P or an equivalent rating), 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) which are fully hedged back into U.S. dollars and do not exceed 15% of the Income Fund’s total assets

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 debt obligations of U.S. and non U.S. issuers rated below A (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.

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

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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%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

1.09%

Expense Example, 1 YEAR

rr_ExpenseExampleYear01

147

Expense Example, 5 YEARS

rr_ExpenseExampleYear05

787

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 U.S. investment grade fixed income securities, including government and corporate securities, mortgage and asset-backed securities, which are generally pass through securities.

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

• high quality commercial paper (within the two highest grades as determined by both Moody’s and S&P or an equivalent rating), 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) which are fully hedged back into U.S. dollars and do not exceed 15% of the Fund’s total assets

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 debt obligations of U.S. and non U.S. issuers rated below A (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, 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 100% of the average value of its portfolio.

Example, heading

rr_ExpenseExampleHeading

* Estimated based on expected allocation as of April 2, 2013. The Fund’s shareholders indirectly bear, pro rata, the expenses of the Fund’s assets invested in the Small Company Growth Portfolio and the Small Company Value Portfolio. These indirect expenses are based on actual expense ratios for the Small Company Growth Portfolio and the Small Company Value Portfolio. The Management Fee charged to the Fund is based on the average daily net assets of the Fund that are not invested in the Small Company Growth Portfolio and the Small Company Value Portfolio. Accordingly, the Management Fee shown in the table is based on the Portfolio’s target allocation of 20% of assets invested in the Small Company Growth Portfolio and 20% of assets invested in the Small Company Value Portfolio. The Fund’s investments in the Small Company Growth Portfolio and the Small Company Value Portfolio are not reflected in the Fund’s expense ratio as shown in the Financial Highlights table of this Prospectus.

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

rr_PerformancePastDoesNotIndicateFuture

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

Bar Chart, Closing

rr_BarChartClosingTextBlock

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

rr_LowestQuarterlyReturnLabel

lowest return for a quarter

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(27.01%)

Performance Table Market Index Changed

rr_PerformanceTableMarketIndexChanged

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:

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

3.56%

^[2]

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%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.25%

Expense Example, 1 YEAR

rr_ExpenseExampleYear01

115

Expense Example, 5 YEARS

rr_ExpenseExampleYear05

622

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:

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, 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 27% of the average value of its portfolio.

Example, heading

rr_ExpenseExampleHeading

* Estimated based on expected allocation as of April 2, 2013. The Fund’s shareholders indirectly bear, pro rata, the expenses of the Fund’s assets invested in the Wilshire International Equity Fund. These indirect expenses are based on actual expense ratios for the Wilshire International Equity Fund. The Management Fee charged to the Fund is based on the average daily net assets of the Fund that are not invested in the Wilshire International Equity Fund. Accordingly, the Management Fee shown in the table is based on the Fund’s target allocation of 20% of assets invested in the Wilshire International Equity Fund. The Fund’s investment in the Wilshire International Equity Fund is not reflected in the Fund’s expense ratio as shown in the Financial Highlights table of this Prospectus.

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

rr_PerformancePastDoesNotIndicateFuture

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

Bar Chart, Closing

rr_BarChartClosingTextBlock

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%)

1 Year

rr_AverageAnnualReturnYear01

17.32%

10 Years

rr_AverageAnnualReturnYear10

8.21%

Risk/Return:

rr_RiskReturnAbstract

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.23%

Expense Example, 1 YEAR

rr_ExpenseExampleYear01

145

Expense Example, 5 YEARS

rr_ExpenseExampleYear05

776

2003

rr_AnnualReturn2003

32.48%

2005

rr_AnnualReturn2005

10.12%

2007

rr_AnnualReturn2007

8.73%

2009

rr_AnnualReturn2009

31.02%

2011

rr_AnnualReturn2011

(13.74%)

1 Year

rr_AverageAnnualReturnYear01

18.33%

10 Years

rr_AverageAnnualReturnYear10

6.03%

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, 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 22% 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 pursues its objective through a diversified portfolio composed primarily of marketable equity securities (including common stocks, preferred stocks and debt securities convertible into common stocks of seasoned U.S.-traded companies). The Fund seeks to achieve its objective by investing in issuers that meet certain investment and socially responsible criteria. Investments in equity securities are limited to issuers which, in the subadviser’s judgment, meet the following criteria:

Socially responsible areas of focus for inclusion:

• Companies with strong environmental management systems, eco-efficiency programs, health and safety procedures, and an overall commitment to continuously improve on environmental matters

• Companies with competitive employee benefit initiatives, workplace programs and non-discrimination policies

• Companies with good transparency and shareholder engagement

Socially responsible areas of exclusion based on revenues:

• Major tobacco, alcohol and gaming device manufacturers

• Major weapons manufacturers

• Major nuclear power generators

• Major pornographic content manufacturers

The Adviser allocates the Fund’s assets between two investment strategies: an appreciation strategy and a large cap core strategy.

Risk, Narrative

rr_RiskNarrativeTextBlock

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

Socially Responsible Risk. The Fund only invests in companies that meet its criteria for socially responsible investing. Because of this restriction, the investments that the subadviser may choose from may be more limited than those of a fund that is not restricted to investing in companies that meet social criteria. As a result, the subadviser may pass up opportunities to buy certain securities when it is otherwise advantageous to do so or may sell certain securities when it is disadvantageous to do so. In addition, investing in socially responsible companies may result in the Fund investing more or less in a specific sector of the economy relative to its benchmark.

Equity Risk. A principal risk of investing in the 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 the 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.

Market Risk. For equity securities, stock market movements will affect the 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 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.

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

Preferred Stock Risk. Preferred stocks are typically subordinated to bonds and other debt instruments in a company’s capital structure, in terms of priority to corporate income, and therefore will be subject to greater credit risk than payments on debt securities. Unlike interest payments on debt securities, preferred stock dividends are payable only if declared by the issuer’s board of directors. Preferred stock also may be subject to optional or mandatory redemption provisions.

Convertible Securities Risk. Convertible securities are fixed income securities that may be converted at a stated price within a specific period of time into a certain quantity of common stock of the same or a different issuer. As with all fixed income securities, the market values of convertible securities tend to decline as interest rates increase and increase as interest rates declines. Convertible securities are senior to common stocks in an issuer’s capital structure, but are usually subordinated to similar non-convertible securities.

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

16.04%

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%

Management Fees

rr_ManagementFeesOverAssets

0.85%

Other Expenses

rr_OtherExpensesOverAssets

0.23%

Expense Example, 1 YEAR

rr_ExpenseExampleYear01

135

Expense Example, 5 YEARS

rr_ExpenseExampleYear05

729

2003

rr_AnnualReturn2003

28.43%

2005

rr_AnnualReturn2005

5.13%

2007

rr_AnnualReturn2007

(2.63%)

2009

rr_AnnualReturn2009

21.51%

2011

rr_AnnualReturn2011

(1.45%)

1 Year

rr_AverageAnnualReturnYear01

15.61%

10 Years

rr_AverageAnnualReturnYear10

5.17%

Risk/Return:

rr_RiskReturnAbstract

Investment objective:

rr_ObjectiveHeading

Investment Objective

Secondary objectives

rr_ObjectiveSecondaryTextBlock

as a secondary objective, capital appreciation. The investment objective of the 2015 ETF Fund may be changed without a shareholder vote.

Fees and expenses of the fund, narrative

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy and hold shares of the 2015 ETF Fund. The table below does not reflect expenses that apply to separate accounts or related annuity contracts, and if such expenses were reflected, fees would be higher.

Date Of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

2014-04-30

Portfolio turnover, narrative

rr_PortfolioTurnoverTextBlock

The 2015 ETF 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 2015 ETF Fund’s performance. During the most recent fiscal year, the 2015 ETF Fund’s portfolio turnover rate was 11% 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 2015 ETF 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 one year of capped expenses, that your investment has a 5% return each year and that the 2015 ETF 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 2015 ETF Fund operates under a fund of funds structure. The 2015 ETF Fund seeks to achieve its investment objective by investing primarily in a portfolio of unaffiliated exchange traded funds (“ETFs”), which are funds traded on national securities exchanges with listed securities, in accordance with weightings determined by Wilshire Associates Incorporated (“Wilshire”). The ETFs, in turn, in an attempt to approximate the investment performance of their respective benchmarks, invest in a variety of U.S. and foreign equity, debt, commodities, money market securities, futures and other instruments in accordance with their own investment policies and strategies.

In managing the 2015 ETF Fund, Wilshire focuses on four key principles: asset allocation, portfolio structure, investment time horizon and fund management. Asset allocation across appropriate asset classes is the central theme of Wilshire’s investment philosophy. The 2015 ETF Fund invests in the ETFs according to a moderate asset allocation strategy designed for investors planning to retire in 2015, plus or minus two to three years. Wilshire seeks to reduce risk by investing in ETFs that are diversified within each asset class. The amounts invested in each of the ETFs will vary from time to time depending on the investment time horizon and Wilshire’s assessment of business, economic and market conditions, including any potential advantage of price shifts between the equity markets and the fixed income markets. The 2015 ETF Fund’s asset allocation will become more conservative over time. In general, however, Wilshire does not anticipate making frequent changes in asset allocation and will not attempt to time the market. As of the date of this Prospectus, the target asset allocation for the 2015 ETF Fund is 44.5% invested in ETFs which invest in fixed income securities and 55.5% invested in ETFs which invest in equity securities. Approximately 15 years after 2015, the 2015 ETF Fund’s target asset allocation will be approximately 70% invested in ETFs which invest in fixed income securities and 30% in ETFs which invest in equity securities.

Risk, Narrative

rr_RiskNarrativeTextBlock

You may lose money by investing in the 2015 ETF Fund. In addition, by investing in the Fund, an investor assumes the same types of risks, either directly or indirectly, as investing in the ETFs. For the 2015 ETF Fund, the risks are as follows:

ETF Risk. ETFs in which the 2015 ETF 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, involve duplication of advisory fees and certain other expenses.

Fund of Funds Risk. The Fund invest in ETFs. Shareholders of the Fund bear their proportionate share of the ETFs’ fees and expenses, as well as their share of the Fund’s fees and expenses. As a result, your cost of investing will be higher than the cost of investing directly in ETFs and may be higher than mutual funds that invest directly in stocks and bonds. Also, the Fund may be prevented from fully allocating assets to certain ETFs due to fund of funds investment limitations.

Future Developments. An ETF may take advantage of other investment practices that are not currently contemplated for use by ETFs, or are not available but may yet be developed, to the extent such investment practices are consistent with an ETF’s investment objective and legally permissible for the ETF. Such investment practices, if they arise, may involve risks that exceed those involved in the activities described above.

Market Risk. For equity securities, stock market movements will affect an ETF’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 an ETF. 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.

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

Capitalization Risk. This is the risk of investments in small-capitalization companies. Investments in small-cap companies tend to be more volatile than investments in large-cap companies. An ETF’s investments in smaller capitalization companies may have additional risks because these companies often have limited product lines, markets or financial resources. This risk is greater for those ETFs with higher asset allocations to small-cap equities.

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 an ETF. The credit risk of an ETF depends on the credit quality of its underlying securities. In general, for debt securities, the lower the credit quality of an ETF’s securities, the higher the ETF’s risk, all other factors such as maturity being equal.

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 an ETF 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), an ETF 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.

Equity Securities Risk. Equity investments, including common stocks, tend to be more volatile than bonds or money market instruments. To the extent an ETF is invested in equity securities, the value of the ETF’s shares will go up and down due to movement in the collective returns of the individual securities held by the ETF. Common stocks are subordinate to preferred stocks in a company’s capital structure, and if a company is liquidated, the claims of secured and unsecured creditors and owners of bonds and preferred stocks take precedence over the claims of those who own common stocks.

Emerging Market Risk. Foreign investment risk may be particularly high to the extent an ETF invests in emerging market securities of issuers based in countries with developing economies. 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.

Foreign (Non-U.S.) Risk. An ETF’s investments in securities of non-U.S. issuers may experience more rapid and extreme changes in value than investments in securities of U.S. companies. The securities markets of many non-U.S. countries are relatively small, with a limited number of companies typically representing a small number of industries. Non-U.S. issuers usually are not subject to the same degree of regulation as U.S. issuers. Reporting, accounting and auditing standards of non-U.S. countries differ, in some cases significantly, from U.S. standards. Nationalization, expropriation or confiscatory taxation, currency blockage, or political changes or diplomatic developments could adversely affect an ETF’s investments in a country other than the United States. To the extent an ETF invests in a particular country or geographic region, the ETF may have more significant risk due to market changes or other factors affecting that country or region, including political instability and unpredictable economic conditions. This risk is greater for those ETFs with higher asset allocations to non-U.S. equities.

Inflation Risk. This is the risk that the value of assets or income from an ETF’s investments will be less in the future as inflation decreases the value of money. As inflation increases, the value of the ETF’s assets can decline as can the value of distributions.

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 security prices move 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.

Investment Style Risk. During certain market conditions, an ETF with a more specific investment style (such as value or growth) may perform less well than an ETF that allows greater flexibility in the investment of assets.

Liquidity Risk. An ETF may invest in certain securities that may be difficult or impossible to sell at a certain time and at a price that the ETF finds to be favorable. An ETF 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.

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.

Real Estate Investment Trust (“REIT”) Risk. REITs are subject to a variety of factors affecting the real estate market generally, such as economic conditions, overbuilding, mortgage rates and availability. In addition, REITs have additional risks because REITs are dependent on the capability of their managers, may have limited diversification, and could be significantly affected by changes in tax laws.

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 an ETF’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.

Bar Chart and Performance Table, Heading

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Performance

Performance, Information Illustrates Variability of Returns

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The information below provides an illustration of how the 2015 ETF Fund’s performance has varied over time.

Bar Chart, Heading

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Calendar Year Returns

Highest Quarterly Return, Label

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highest return for a quarter

Highest Quarterly Return

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12.34%

Lowest Quarterly Return Date

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Dec. 31, 2008

Performance Table:

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

Risk/Return:

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5 Years

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2.04%

Inception Date

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May 01, 2006

Risk/Return:

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

2.98%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 01, 2006

Risk/Return:

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Distribution and Service (12b-1) Fees

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0.25%

Acquired Fund Fees and Expenses

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0.15%

Less Expense Reimbursement

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(0.11%)

^[3]

Expense Example, 1 YEAR

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77

Expense Example, 5 YEARS

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417

2007

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4.57%

2009

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20.49%

2011

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1.56%

1 Year

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12.48%

Since Inception

rr_AverageAnnualReturnSinceInception

3.79%

Risk/Return

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Wilshire 2025 ETF Fund

Investment objective

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The Wilshire 2025 ETF Fund’s (“2025 ETF Fund” or “Fund”) investment objective is to provide high total return until its target retirement date. Thereafter the 2025 ETF Fund’s objective will be to seek high current income and,

Fees and expenses of the fund:

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Fees and Expenses of the 2025 ETF 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

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Portfolio Turnover

Portfolio Turnover Rate

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6.00%

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 2025 ETF Fund.

Performance, Narrative

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The information below provides an illustration of how the 2025 ETF Fund’s performance has varied over time. The bar chart and table provide some indication of the risks of investing in the 2025 ETF Fund by showing the changes in the 2025 ETF Fund’s investment performance from year to year during the periods indicated and by showing how the average annual total returns for the one-year and since inception 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 2025 ETF 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 2025 ETF 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 13.11% (quarter ended 9/30/09) and the lowest return for a quarter was -13.38% (quarter ended 12/31/08).

Highest Quarterly Return Date

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Sep. 30, 2009

Lowest Quarterly Return, Label

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lowest return for a quarter

Lowest Quarterly Return

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(13.38%)

1 Year

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16.07%

Since Inception

rr_AverageAnnualReturnSinceInception

3.63%

1 Year

rr_AverageAnnualReturnYear01

12.51%

Since Inception

rr_AverageAnnualReturnSinceInception

3.93%

Management Fees

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0.25%

Other Expenses

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0.21%

Gross Annual Expenses

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0.85%

Total Annual Fund Operating Expenses

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0.74%

Expense Example, 3 YEARS

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237

Expense Example, 10 YEARS

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918

2008

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(28.11%)

2010

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11.77%

2012

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12.73%

5 Years

rr_AverageAnnualReturnYear05

1.84%

Inception Date

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May 01, 2006

Risk/Return:

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Investment objective:

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Investment Objective

Secondary objectives

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as a secondary objective, capital appreciation. The investment objective of the 2035 ETF Fund may be changed without a shareholder vote.

Fees and expenses of the fund, narrative

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This table describes the fees and expenses that you may pay if you buy and hold shares of the 2035 ETF Fund. The table below does not reflect expenses that apply to separate accounts or related annuity contracts, and if such expenses were reflected, fees would be higher.

Date Of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

2014-04-30

Portfolio turnover, narrative

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The 2035 ETF 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 2035 ETF Fund’s performance. During the most recent fiscal year, the 2035 ETF Fund’s portfolio turnover rate was 6% of the average value of its portfolio.

Expense Example, Narrative

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Example: This example is intended to help you compare the cost of investing in the 2035 ETF 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 one year of capped expenses, that your investment has a 5% return each year and that the 2035 ETF 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

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The 2035 ETF Fund operates under a fund of funds structure. The 2035 ETF Fund seeks to achieve its investment objective by investing primarily in a portfolio of unaffiliated exchange traded funds (“ETFs”), which are funds traded on national securities exchanges with listed securities, in accordance with weightings determined by Wilshire Associates Incorporated (“Wilshire”). The ETFs, in turn, in an attempt to approximate the investment performance of their respective benchmarks, invest in a variety of U.S. and foreign equity, debt, commodities, money market securities, futures and other instruments in accordance with their own investment policies and strategies.

In managing the 2035 ETF Fund, Wilshire focuses on four key principles: asset allocation, portfolio structure, investment time horizon and fund management. Asset allocation across appropriate asset classes is the central theme of Wilshire’s investment philosophy. The 2035 ETF Fund invests in the ETFs according to a moderate asset allocation strategy designed for investors planning to retire in 2035, plus or minus two to three years. Wilshire seeks to reduce risk by investing in ETFs that are diversified within each asset class. The amounts invested in each of the ETFs will vary from time to time depending on the investment time horizon and Wilshire’s assessment of business, economic and market conditions, including any potential advantage of price shifts between the equity markets and the fixed income markets. The 2035 ETF Fund’s asset allocation will become more conservative over time. In general, however, Wilshire does not anticipate making frequent changes in asset allocation and will not attempt to time the market. As of the date of this Prospectus, the target asset allocation for the 2035 ETF Fund is 30.2% invested in ETFs which invest in fixed income securities and 69.8% invested in ETFs which invest in equity securities. Approximately 15 years after 2035, the 2035 ETF Fund’s target asset allocation will be approximately 70% invested in ETFs which invest in fixed income securities and 30% in ETFs which invest in equity securities.

Risk, Narrative

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You may lose money by investing in the 2035 ETF Fund. In addition, by investing in the Fund, an investor assumes the same types of risks, either directly or indirectly, as investing in the ETFs. For the 2035 ETF Fund, the risks are as follows:

ETF Risk. ETFs in which the 2035 ETF 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, involve duplication of advisory fees and certain other expenses.

Fund of Funds Risk. The Fund invest in ETFs. Shareholders of the Fund bear their proportionate share of the ETFs’ fees and expenses, as well as their share of the Fund’s fees and expenses. As a result, your cost of investing will be higher than the cost of investing directly in ETFs and may be higher than mutual funds that invest directly in stocks and bonds. Also, the Fund may be prevented from fully allocating assets to certain ETFs due to fund of funds investment limitations.

Future Developments. An ETF may take advantage of other investment practices that are not currently contemplated for use by ETFs, or are not available but may yet be developed, to the extent such investment practices are consistent with an ETF’s investment objective and legally permissible for the ETF. Such investment practices, if they arise, may involve risks that exceed those involved in the activities described above.

Market Risk. For equity securities, stock market movements will affect an ETF’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 an ETF. 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.

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

More information about risks, including additional risk facts not discussed above, is included in the “More About Risks” section and the 2035 ETF Fund’s Statement of Additional Information.

Capitalization Risk. This is the risk of investments in small-capitalization companies. Investments in small-cap companies tend to be more volatile than investments in large-cap companies. An ETF’s investments in smaller capitalization companies may have additional risks because these companies often have limited product lines, markets or financial resources. This risk is greater for those ETFs with higher asset allocations to small-cap equities.

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 an ETF. The credit risk of an ETF depends on the credit quality of its underlying securities. In general, for debt securities, the lower the credit quality of an ETF’s securities, the higher the ETF’s risk, all other factors such as maturity being equal.

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 an ETF 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), an ETF 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 that an ETF uses derivatives, an ETF will (to the extent required by applicable law) either(1) segregate cash or liquid assets in the prescribed amount or (2) otherwise “cover” its future obligations under the transaction, such as by holding an offsetting investment.