v3.25.2
Shareholder Report, Average Annual Return (Details)
 12 Months Ended 60 Months Ended 120 Months Ended
May 31, 2025
May 31, 2025
May 31, 2025
C000021763 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Asset Allocation Fund    
Average Annual Return, Percent 8.30% 10.58% 6.16%
C000021764 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name International Equities Index Fund    
Average Annual Return, Percent 12.32% 10.98% 5.58%
C000021765 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name International Government Bond Fund    
Average Annual Return, Percent 6.04% (1.01%) 0.97%
C000021766 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name International Growth Fund    
Average Annual Return, Percent 18.44% 8.35% 7.21%
C000021768 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Large Capital Growth Fund    
Average Annual Return, Percent 6.55% 12.89% 12.75%
C000021769 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Mid Cap Index Fund    
Average Annual Return, Percent 1.60% 12.49% 8.35%
C000021770 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Mid Cap Strategic Growth Fund    
Average Annual Return, Percent 13.34% 13.15% 11.91%
C000021772 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Nasdaq-100® Index Fund    
Average Annual Return, Percent 15.41% 17.75% 17.33%
C000021773 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Science & Technology Fund    
Average Annual Return, Percent 16.20% 15.03% 16.65%
C000021774 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Systematic Growth Fund    
Average Annual Return, Percent 15.29% 11.59% 13.26%
C000021776 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Small Cap Index Fund    
Average Annual Return, Percent 0.73% 9.22% 6.32%
C000021777 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name International Socially Responsible Fund    
Average Annual Return, Percent 11.22% 10.60% 7.42%
C000021778 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Stock Index Fund    
Average Annual Return, Percent 13.17% 15.59% 12.50%
C000021782 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Government Securities Fund    
Average Annual Return, Percent 4.93% (1.19%) 0.98%
C000021783 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Systematic Core Fund    
Average Annual Return, Percent 11.71% 14.80% 12.00%
C000021785 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Dividend Value Fund    
Average Annual Return, Percent 9.75% 12.60% 8.77%
C000021786 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Inflation Protected Fund    
Average Annual Return, Percent 3.51% 1.81% 2.17%
C000022843 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Systematic Value Fund    
Average Annual Return, Percent 12.47% 13.48% 8.35%
C000022844 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name International Value Fund    
Average Annual Return, Percent 16.84% 13.30% 4.64%
C000022845 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Emerging Economies Fund    
Average Annual Return, Percent 11.67% 7.03% 3.70%
C000022846 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Global Strategy Fund    
Average Annual Return, Percent 9.68% 6.82% 3.43%
C000022849 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Small Cap Special Values Fund    
Average Annual Return, Percent (7.66%) 11.31% 6.92%
C000022851 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Growth Fund    
Average Annual Return, Percent 15.84% 14.44% 13.99%
C000059956 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Global Real Estate Fund    
Average Annual Return, Percent 9.87% 3.96% 2.91%
C000121199 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Dynamic Allocation Fund    
Average Annual Return, Percent 8.22% 6.09% 5.81%
C000222575 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Aggressive Growth Lifestyle Fund    
Average Annual Return, Percent 10.55% 10.88% 7.50%
C000222576 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name U.S. Socially Responsible Fund    
Average Annual Return, Percent 11.18% 14.20% 11.69%
C000222577 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Capital Appreciation Fund    
Average Annual Return, Percent 14.63% 16.89% 13.64%
C000222578 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Conservative Growth Lifestyle Fund    
Average Annual Return, Percent 7.73% 5.68% 4.46%
C000222579 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Core Bond Fund    
Average Annual Return, Percent 5.68% (0.23%) 1.70%
C000222580 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name High Yield Bond Fund    
Average Annual Return, Percent 8.42% 5.39% 4.47%
C000222581 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name International Opportunities Fund    
Average Annual Return, Percent 10.84% 5.87% 5.54%
C000222582 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Mid Cap Value Fund    
Average Annual Return, Percent 3.31% 13.90% 7.67%
C000222583 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Moderate Growth Lifestyle Fund    
Average Annual Return, Percent 9.14% 8.79% 6.49%
C000222584 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Small Cap Value Fund    
Average Annual Return, Percent (2.78%) 12.63% 5.49%
C000224903 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Small Cap Growth Fund    
Average Annual Return, Percent 2.41% 3.97% 8.86%
Standard & Poor's 500 Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name S&P 500® Index    
Average Annual Return, Percent 13.52% 15.94% 12.86%
Bloomberg U S Aggregate Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg U.S. Aggregate Bond Index    
Average Annual Return, Percent 5.46% (0.90%) 1.49%
MSCI ACWI Index net [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name MSCI ACWI Index (net)    
Average Annual Return, Percent 13.65% 13.37% 9.25%
MSCI ACWI ex USA Index net [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name MSCI ACWI ex USA Index (net)    
Average Annual Return, Percent 13.75% 10.37% 5.47%
Bloomberg Global Aggregate Index USD hedged [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Global Aggregate Index (USD hedged)    
Average Annual Return, Percent 6.06% 0.17% 2.11%
Bloomberg U S Universal Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg U.S. Universal Index    
Average Annual Return, Percent 5.84% (0.29%) 1.84%
Russell 3000 Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 3000® Index    
Average Annual Return, Percent 13.12% 15.34% 12.21%
MSCI EAFE Index net [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name MSCI EAFE Index (net)    
Average Annual Return, Percent 13.33% 11.42% 5.97%
Russell 1000 Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 1000® Index    
Average Annual Return, Percent 13.73% 15.66% 12.58%
Sixty S And P 500 Index 40 Bloomberg U S Aggregate Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name 60% S&P 500® Index; 40% Bloomberg U.S. Aggregate Bond Index    
Average Annual Return, Percent 10.40% 9.14% 8.45%
Russell 1000 Growth Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 1000® Growth Index    
Average Annual Return, Percent 17.62% 17.69% 16.08%
Twenty Six Russell 3000 Index 9 MSCI EAFE Index net 65 Bloomberg U S Aggregate Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name 26% Russell 3000® Index; 9% MSCI EAFE Index (net); 65% Bloomberg U.S. Aggregate Bond Index    
Average Annual Return, Percent 8.28% 4.42% 4.85%
FTSE EPRA NAREIT Developed Index net [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name FTSE EPRA /NAREIT Developed Index (net)    
Average Annual Return, Percent 10.59% 5.45% 2.66%
Russell 1000 Value Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 1000® Value Index    
Average Annual Return, Percent 8.91% 13.02% 8.60%
Sixty MSCI ACWI Index net 40 Bloomberg Global Aggregate Index USD hedged [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name 60% MSCI ACWI Index (net); 40% Bloomberg Global Aggregate Index (USD hedged)    
Average Annual Return, Percent 10.65% 8.11% 6.58%
MSCI Emerging Markets Index net [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name MSCI Emerging Markets Index (net)    
Average Annual Return, Percent 13.04% 7.07% 3.93%
Bloomberg U S Government Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg U.S. Government Bond Index    
Average Annual Return, Percent 5.05% (1.76%) 1.01%
Seventy FTSE WGBI Index unhedged 30 JPMorgan EMBI Global Diversified Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name 70% FTSE WGBI Index (unhedged); 30% JPMorgan EMBI Global Diversified Index    
Average Annual Return, Percent 6.96% (1.30%) 1.22%
MSCI EAFE Value Index net [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name MSCI EAFE Value Index (net)    
Average Annual Return, Percent 18.72% 14.70% 5.54%
MSCI ACWI ex USA SMID Cap Index net [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name MSCI ACWI ex USA SMID Cap Index (net)    
Average Annual Return, Percent 13.90% 9.94% 5.49%
FTSE US High Yield Market Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name FTSE US High-Yield Market Index    
Average Annual Return, Percent 9.58% 5.98% 4.89%
Bloomberg U S TIPS Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg U.S. TIPS Index    
Average Annual Return, Percent 5.67% 1.64% 2.47%
S And P MidCap 400 Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name S&P MidCap 400® Index    
Average Annual Return, Percent 2.17% 12.93% 8.73%
Russell Midcap Growth Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell Midcap® Growth Index    
Average Annual Return, Percent 23.23% 12.22% 11.47%
Russell Midcap Value Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell Midcap® Value Index    
Average Annual Return, Percent 6.03% 13.18% 7.74%
Russell 2000 Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 2000® Index    
Average Annual Return, Percent 1.19% 9.64% 6.64%
S And P North American Technology Sector Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name S&P North American Technology Sector Index    
Average Annual Return, Percent 16.50% 18.91% 19.97%
Forty One Russell 3000 Index 14 MSCI EAFE Index net 45 Bloomberg U S Aggregate Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name 41% Russell 3000® Index; 14% MSCI EAFE Index (net); 45% Bloomberg U.S. Aggregate Bond Index    
Average Annual Return, Percent 9.87% 7.49% 6.71%
Nasdaq 100 Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Nasdaq-100® Index    
Average Annual Return, Percent 16.02% 18.37% 17.96%
Russell 2000 Value Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 2000® Value Index    
Average Annual Return, Percent (1.14%) 12.03% 6.22%
Russell 2000 Growth Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 2000® Growth Index    
Average Annual Return, Percent 3.45% 7.00% 6.67%
Fifty Six Russell 3000 Index 19 MSCI EAFE Index net 25 Bloomberg U S Aggregate Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name 56% Russell 3000® Index; 19% MSCI EAFE Index (net); 25% Bloomberg U.S. Aggregate Bond Index    
Average Annual Return, Percent 11.44% 10.57% 8.51%