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
C000129654                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value $ 10,000 $ 10,328 $ 10,178 $ 10,559 $ 10,818 $ 11,019 $ 11,230 $ 11,264 $ 11,264 $ 11,432 $ 11,145 $ 11,487 $ 11,642 $ 12,075 $ 12,343 $ 12,326 $ 12,284 $ 13,169 $ 13,585 $ 14,010 $ 14,523 $ 14,869 $ 14,701 $ 14,324 $ 13,648 $ 13,232 $ 13,256 $ 13,281 $ 13,474 $ 13,757 $ 13,886 $ 14,561 $ 14,840 $ 15,438 $ 15,717 $ 15,822 $ 15,918 $ 16,553 $ 16,980 $ 17,513 $ 17,791
C000129655                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 10,000 10,319 10,159 10,530 10,779 10,970 11,171 11,204 11,194 11,361 11,076 11,404 11,557 11,965 12,230 12,204 12,152 13,015 13,426 13,845 14,338 14,667 14,502 14,112 13,449 13,019 13,042 13,058 13,234 13,511 13,624 14,285 14,544 15,126 15,384 15,477 15,557 16,169 16,582 17,090 17,358
C000169038                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 500,000 516,401 508,903 528,455 540,923 550,994 561,544 563,702 563,702 572,594 558,267 575,403 583,667 605,361 619,307 618,474 616,338 661,201 682,565 703,860 730,115 747,991 740,170 720,721 687,365 666,518 668,305 669,269 678,997 693,913 701,047 735,032 749,103 779,924 793,995 799,519 805,091 837,127 859,413 886,244 901,027
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 Retirement Income Index                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 10,000 10,249 10,113 10,394 10,587 10,754 10,989 11,001 11,056 11,247 10,986 11,245 11,382 11,801 12,085 12,038 12,186 12,786 13,095 13,264 13,610 13,916 13,811 13,458 12,844 12,509 12,568 12,647 12,869 13,102 13,207 13,803 14,022 14,681 14,842 14,971 15,131 15,775 16,253 16,737 17,036
S&P Target Date Retirement Income Index                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value 10,000 10,249 10,113 10,394 10,587 10,754 10,989 11,001 11,056 11,247 10,986 11,245 11,382 11,801 12,085 12,038 12,186 12,786 13,095 13,264 13,610 13,916 13,811 13,458 12,844 12,509 12,568 12,647 12,869 13,102 13,207 13,803 14,022 14,681 14,842 14,971 15,131 15,775 16,253 16,737 17,036
S&P Target Date Retirement Income Index                                                                                  
Account Value [Line Items]                                                                                  
Accumulated Value $ 500,000 $ 512,436 $ 505,671 $ 519,688 $ 529,362 $ 537,707 $ 549,432 $ 550,061 $ 552,788 $ 562,370 $ 549,322 $ 562,275 $ 569,093 $ 590,031 $ 604,235 $ 601,880 $ 609,301 $ 639,318 $ 654,754 $ 663,217 $ 680,514 $ 695,799 $ 690,562 $ 672,885 $ 642,211 $ 625,459 $ 628,405 $ 632,375 $ 643,435 $ 655,124 $ 660,357 $ 690,142 $ 701,108 $ 734,050 $ 742,086 $ 748,542 $ 756,539 $ 788,743 $ 812,657 $ 836,859 $ 851,777