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] | C000129660      
Average Annual Return [Line Items]      
Average Annual Return, Percent 11.95% 4.23% 6.07%
Without Sales Load [Member] | C000129661      
Average Annual Return [Line Items]      
Average Annual Return, Percent 11.66% 3.97% 5.79%
Without Sales Load [Member] | C000169041      
Average Annual Return [Line Items]      
Average Annual Return, Percent 12.21% 4.42% 6.22%
Bloomberg U.S. Aggregate Bond Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 5.13% 0.17% 1.70%
Bloomberg U.S. Aggregate Bond Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 5.13% 0.17% 1.70%
Bloomberg U.S. Aggregate Bond Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 5.13% 0.17% 1.70%
S&P Target Date 2010 Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 12.87% 4.81% 6.04%
S&P Target Date 2010 Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 12.87% 4.81% 6.04%
S&P Target Date 2010 Index      
Average Annual Return [Line Items]      
Average Annual Return, Percent 12.87% 4.81% 6.04%