Shareholder Report, Average Annual Return (Details)	12 Months Ended	60 Months Ended	120 Months Ended
Shareholder Report, Average Annual Return (Details)	May 31, 2026	May 31, 2026	May 31, 2026
Without Sales Load [Member] \| C000129670
Average Annual Return [Line Items]
Average Annual Return, Percent	18.38%	6.46%	9.16%
Without Sales Load [Member] \| C000129671
Average Annual Return [Line Items]
Average Annual Return, Percent	18.07%	6.18%	8.89%
Without Sales Load [Member] \| C000169046
Average Annual Return [Line Items]
Average Annual Return, Percent	18.53%	6.62%	9.33%
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 2035 Index
Average Annual Return [Line Items]
Average Annual Return, Percent	21.69%	8.14%	9.92%
S&P Target Date 2035 Index
Average Annual Return [Line Items]
Average Annual Return, Percent	21.69%	8.14%	9.92%
S&P Target Date 2035 Index
Average Annual Return [Line Items]
Average Annual Return, Percent	21.69%	8.14%	9.92%