v3.26.1
Shareholder Report, Line Graph (Details) - USD ($)
 3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended 15 Months Ended 18 Months Ended 21 Months Ended 24 Months Ended 27 Months Ended 30 Months Ended 33 Months Ended 36 Months Ended 39 Months Ended 42 Months Ended 45 Months Ended 48 Months Ended 51 Months Ended 54 Months Ended 57 Months Ended 60 Months Ended 63 Months Ended 66 Months Ended 69 Months Ended 72 Months Ended 75 Months Ended 78 Months Ended 81 Months Ended 84 Months Ended 87 Months Ended 90 Months Ended 93 Months Ended 96 Months Ended 99 Months Ended 102 Months Ended 105 Months Ended 108 Months Ended 111 Months Ended 114 Months Ended 117 Months Ended 120 Months Ended
May 31, 2016
Aug. 31, 2016
Nov. 30, 2016
Feb. 28, 2017
May 31, 2017
Aug. 31, 2017
Nov. 30, 2017
Feb. 28, 2018
May 31, 2018
Aug. 31, 2018
Nov. 30, 2018
Feb. 28, 2019
May 31, 2019
Aug. 31, 2019
Nov. 30, 2019
Feb. 29, 2020
May 31, 2020
Aug. 31, 2020
Nov. 30, 2020
Feb. 28, 2021
May 31, 2021
Aug. 31, 2021
Nov. 30, 2021
Feb. 28, 2022
May 31, 2022
Aug. 31, 2022
Nov. 30, 2022
Feb. 28, 2023
May 31, 2023
Aug. 31, 2023
Nov. 30, 2023
Feb. 29, 2024
May 31, 2024
Aug. 31, 2024
Nov. 30, 2024
Feb. 28, 2025
May 31, 2025
Aug. 31, 2025
Nov. 30, 2025
Feb. 28, 2026
May 31, 2026
C000129662                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value $ 10,000 $ 10,331 $ 10,203 $ 10,625 $ 10,908 $ 11,126 $ 11,371 $ 11,438 $ 11,438 $ 11,624 $ 11,301 $ 11,660 $ 11,803 $ 12,244 $ 12,542 $ 12,493 $ 12,450 $ 13,405 $ 13,871 $ 14,363 $ 14,926 $ 15,286 $ 15,128 $ 14,711 $ 14,017 $ 13,573 $ 13,633 $ 13,640 $ 13,835 $ 14,174 $ 14,305 $ 15,035 $ 15,333 $ 15,969 $ 16,253 $ 16,361 $ 16,461 $ 17,144 $ 17,600 $ 18,180 $ 18,496
C000129663                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 10,000 10,323 10,194 10,598 10,872 11,089 11,325 11,373 11,363 11,548 11,217 11,556 11,699 12,116 12,402 12,354 12,312 13,235 13,686 14,172 14,716 15,071 14,893 14,482 13,787 13,339 13,387 13,384 13,576 13,896 14,011 14,714 15,005 15,614 15,892 15,977 16,061 16,714 17,159 17,703 18,012
C000169042                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 500,000 516,575 510,589 531,264 545,443 556,787 569,076 572,419 572,419 582,212 566,053 583,787 591,495 613,593 628,496 626,054 624,460 672,822 696,206 720,861 749,606 768,205 760,314 740,023 705,128 682,867 685,875 687,081 696,934 714,012 721,238 757,884 773,588 805,679 820,700 826,259 831,297 866,564 890,315 919,773 935,802
Bloomberg U.S. Aggregate Bond Index                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 10,000 10,232 9,908 10,008 10,158 10,283 10,227 10,059 10,120 10,175 10,089 10,378 10,768 11,210 11,178 11,590 11,781 11,936 11,992 11,750 11,734 11,925 11,854 11,440 10,769 10,552 10,332 10,328 10,538 10,426 10,454 10,671 10,676 11,187 11,173 11,291 11,258 11,538 11,809 11,998 11,836
Bloomberg U.S. Aggregate Bond Index                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 10,000 10,232 9,908 10,008 10,158 10,283 10,227 10,059 10,120 10,175 10,089 10,378 10,768 11,210 11,178 11,590 11,781 11,936 11,992 11,750 11,734 11,925 11,854 11,440 10,769 10,552 10,332 10,328 10,538 10,426 10,454 10,671 10,676 11,187 11,173 11,291 11,258 11,538 11,809 11,998 11,836
Bloomberg U.S. Aggregate Bond Index                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 500,000 511,616 495,403 500,416 507,893 514,136 511,326 502,944 505,990 508,741 504,464 518,886 538,376 560,492 558,902 579,506 589,067 596,775 599,611 587,524 586,682 596,272 592,695 571,989 538,444 527,606 516,596 516,381 526,907 521,310 522,690 533,562 533,786 559,349 558,625 564,552 562,924 576,891 590,474 599,896 591,821
S&P Target Date 2015 Index                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 10,000 10,296 10,211 10,622 10,883 11,084 11,422 11,458 11,524 11,784 11,433 11,716 11,794 12,243 12,621 12,457 12,575 13,391 13,821 14,156 14,704 15,091 14,967 14,582 13,899 13,500 13,621 13,691 13,936 14,244 14,357 15,065 15,329 16,064 16,279 16,392 16,566 17,329 17,881 18,464 18,854
S&P Target Date 2015 Index                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 10,000 10,296 10,211 10,622 10,883 11,084 11,422 11,458 11,524 11,784 11,433 11,716 11,794 12,243 12,621 12,457 12,575 13,391 13,821 14,156 14,704 15,091 14,967 14,582 13,899 13,500 13,621 13,691 13,936 14,244 14,357 15,065 15,329 16,064 16,279 16,392 16,566 17,329 17,881 18,464 18,854
S&P Target Date 2015 Index                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value $ 500,000 $ 514,808 $ 510,537 $ 531,117 $ 544,153 $ 554,191 $ 571,118 $ 572,881 $ 576,193 $ 589,219 $ 571,641 $ 585,776 $ 589,675 $ 612,140 $ 631,073 $ 622,866 $ 628,765 $ 669,529 $ 691,026 $ 707,799 $ 735,201 $ 754,550 $ 748,362 $ 729,121 $ 694,949 $ 675,014 $ 681,039 $ 684,564 $ 696,811 $ 712,213 $ 717,838 $ 753,247 $ 766,451 $ 803,205 $ 813,938 $ 819,616 $ 828,293 $ 866,450 $ 894,049 $ 923,177 $ 942,719