v3.26.1
Average Annual Total Returns
 12 Months Ended 60 Months Ended 117 Months Ended 120 Months Ended
Apr. 30, 2026
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Wilshire 5000 Index (reflects no deduction for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Wilshire 5000 Index(reflects no deduction for fees, expenses or taxes)        
Average Annual Return, Percent   17.13% 13.40%   14.45%
Russell 1000® Growth Total Return Index (reflects no deduction for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Russell 1000® Growth Total Return Index(reflects no deduction for fees, expenses or taxes)        
Average Annual Return, Percent   18.70% 15.35%   18.14%
Russell 1000® Value Total Return Index (reflects no deduction for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Russell 1000® Value Total Return Index (reflects no deduction for fees, expenses or taxes)        
Average Annual Return, Percent   15.91% 11.33%   10.53%
Russell 2000® Growth Total Return Index (reflects no deduction for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Russell 2000® Growth Total Return Index (reflects no deduction for fees, expenses or taxes)        
Average Annual Return, Percent   13.01% 3.18%   9.57%
Russell 2000 Value Index (reflects no deduction for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Russell 2000 Value Index(reflects no deduction for fees, expenses or taxes)        
Average Annual Return, Percent   12.59% 8.88%   9.27%
MSCI All Country World Index ex-US Investable Market Index (reflects no deduction for fees, expenses and taxes)          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] MSCI All Country World Index ex-US Investable Market Index(reflects no deduction for fees, expenses and taxes)        
Average Annual Return, Percent   31.96% 7.77%   8.37%
Bloomberg U.S. Universal Bond Index (reflects no deduction for fees, expenses and taxes)          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Bloomberg U.S. Universal Bond Index (reflects no deduction for fees, expenses and taxes)        
Average Annual Return, Percent   7.58% 0.06% 2.21%  
Custom Blended Index (reflects no deduction for fees, expenses and taxes)          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] [1] Custom Blended Index(2)(reflects no deduction for fees, expenses and taxes)        
Average Annual Return, Percent [1]   8.01% 1.27% 3.16%  
Large Company Growth Portfolio - Investment Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   21.97% 14.27%   16.16%
Large Company Growth Portfolio - Investment Class | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions        
Average Annual Return, Percent   15.34% 10.31%   12.39%
Large Company Growth Portfolio - Investment Class | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions and Sale of Shares        
Average Annual Return, Percent   16.61% 10.41%   12.19%
Large Company Growth Portfolio - Institutional Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   22.36% 14.62%   16.53%
Large Company Value Portfolio - Investment Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   15.73% 11.13%   9.31%
Large Company Value Portfolio - Investment Class | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions        
Average Annual Return, Percent   13.08% 8.96%   7.35%
Large Company Value Portfolio - Investment Class | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions and Sale of Shares        
Average Annual Return, Percent   11.14% 8.47%   7.04%
Large Company Value Portfolio - Institutional Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   16.03% 11.45%   9.59%
Small Company Growth Portfolio - Investment Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   7.91% 0.51%   7.82%
Small Company Growth Portfolio - Investment Class | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions        
Average Annual Return, Percent   7.91% (2.04%)   5.32%
Small Company Growth Portfolio - Investment Class | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions and Sale of Shares        
Average Annual Return, Percent   4.68% 0.12% [2]   5.85% [2]
Small Company Growth Portfolio - Institutional Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   8.10% 0.76%   8.09%
Small Company Value Portfolio - Investment Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   10.35% 10.54%   8.60%
Small Company Value Portfolio - Investment Class | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions        
Average Annual Return, Percent   7.68% 8.80%   6.91%
Small Company Value Portfolio - Investment Class | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions and Sale of Shares        
Average Annual Return, Percent   7.90% [2] 8.19%   6.58%
Small Company Value Portfolio - Institutional Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   10.60% 10.81%   8.87%
Wilshire 5000 IndexSM Fund - Investment Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   16.29% 12.63%   13.66%
Wilshire 5000 IndexSM Fund - Investment Class | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions        
Average Annual Return, Percent   14.02% 11.24%   12.06%
Wilshire 5000 IndexSM Fund - Investment Class | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions and Sale of Shares        
Average Annual Return, Percent   11.29% 9.87%   10.94%
Wilshire 5000 IndexSM Fund - Institutional Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   16.56% 12.88%   13.96%
Wilshire International Equity Fund - Investment Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   33.71% 8.64%   9.30%
Wilshire International Equity Fund - Investment Class | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions        
Average Annual Return, Percent   30.19% 6.61%   7.97%
Wilshire International Equity Fund - Investment Class | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions and Sale of Shares        
Average Annual Return, Percent   22.59% 6.66% [3]   7.49%
Wilshire International Equity Fund - Institutional Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   33.93% 8.92%   9.59%
Wilshire Income Opportunities Fund - Investment Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   7.18% 1.02% 2.74%  
Performance Inception Date Mar. 30, 2016        
Wilshire Income Opportunities Fund - Investment Class | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions        
Average Annual Return, Percent   5.25% (0.45%) 1.24%  
Wilshire Income Opportunities Fund - Investment Class | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions and Sale of Shares        
Average Annual Return, Percent   4.23% 0.16% [4] 1.47% [4]  
Wilshire Income Opportunities Fund - Institutional Class          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   7.47% 1.29% 2.97%  
Performance Inception Date Mar. 30, 2016        
[1] The Custom Blended Index consists of 70% Bloomberg U.S. Universal Index, 10% Bloomberg U.S. Corporate High Yield 2% Issuer Capped Bond Index, 10% S&P/LSTA Leveraged Loan Index, and 10% Bloomberg Emerging Markets USD Aggregate Bond Index.
[2] In certain cases, the figure representing “Return After Taxes on Distributions and Sale of Shares” may be higher than the other return figures of the same period. A higher after-tax return results when a capital loss occurs upon redemption and provides an assumed tax deduction that benefits the investor.
[3] In certain cases, the figure representing “Return After Taxes on Distributions and Sale of Shares” may be higher than the other return figures of the same period. A higher after-tax return results when a capital loss occurs upon redemption and provides an assumed tax deduction that benefits the investor.
[4] In certain cases, the figure representing “Return After Taxes on Distributions and Sale of Shares” may be higher than the other return figures of the same period. A higher after-tax return results when a capital loss occurs upon redemption and provides an assumed tax deduction that benefits the investor.