v3.26.1
Shareholder Report, Average Annual Return (Details)
 12 Months Ended 60 Months Ended 120 Months Ended
May 31, 2026
May 31, 2026
May 31, 2026
Without Sales Load [Member] | C000129672      
Average Annual Return [Line Items]      
Average Annual Return, Percent 20.80% 7.16% 9.95%
Without Sales Load [Member] | C000129673      
Average Annual Return [Line Items]      
Average Annual Return, Percent 20.52% 6.89% 9.66%
Without Sales Load [Member] | C000169047      
Average Annual Return [Line Items]      
Average Annual Return, Percent 21.07% 7.35% 10.11%
Russell 3000 Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 29.45% 12.92% 15.12%
Russell 3000 Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 29.45% 12.92% 15.12%
Russell 3000 Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 29.45% 12.92% 15.12%
S&P Target Date 2040 Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 24.41% 9.16% 10.78%
S&P Target Date 2040 Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 24.41% 9.16% 10.78%
S&P Target Date 2040 Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 24.41% 9.16% 10.78%