v3.26.1
Average Annual Total Returns
12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
S&P 500 Index (reflects no deduction for fees, expenses or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 17.88% 14.42% 14.82%
Elfun Trusts      
Prospectus [Line Items]      
Average Annual Return, Percent 16.68% 14.70% 15.79%
Elfun Trusts | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 14.20% 12.47% 13.27%
Elfun Trusts | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 11.67% 11.34% 12.35%