Shareholder Report, Line Graph (Details) - USD ($) |
May 31, 2025 |
Feb. 28, 2025 |
Nov. 30, 2024 |
Aug. 31, 2024 |
May 31, 2024 |
Feb. 29, 2024 |
Nov. 30, 2023 |
Aug. 31, 2023 |
May 31, 2023 |
Feb. 28, 2023 |
Nov. 30, 2022 |
Aug. 31, 2022 |
May 31, 2022 |
Feb. 28, 2022 |
Nov. 30, 2021 |
Aug. 31, 2021 |
May 31, 2021 |
Feb. 28, 2021 |
Nov. 30, 2020 |
Aug. 31, 2020 |
May 31, 2020 |
Feb. 29, 2020 |
Nov. 30, 2019 |
Aug. 31, 2019 |
May 31, 2019 |
Feb. 28, 2019 |
Nov. 30, 2018 |
Aug. 31, 2018 |
May 31, 2018 |
Feb. 28, 2018 |
Nov. 30, 2017 |
Aug. 31, 2017 |
May 31, 2017 |
Feb. 28, 2017 |
Nov. 30, 2016 |
Nov. 15, 2016 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| C000174964 | ||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||||||||||||||||
| Account Value | $ 11,671 | $ 11,745 | $ 11,578 | $ 11,574 | $ 11,027 | $ 11,000 | $ 10,741 | $ 10,725 | $ 10,852 | $ 10,709 | $ 10,617 | $ 10,985 | $ 11,268 | $ 12,163 | $ 12,575 | $ 12,641 | $ 12,381 | $ 12,350 | $ 12,395 | $ 12,228 | $ 11,715 | $ 11,851 | $ 11,485 | $ 11,482 | $ 11,056 | $ 10,647 | $ 10,324 | $ 10,417 | $ 10,367 | $ 10,327 | $ 10,413 | $ 10,418 | $ 10,263 | $ 10,067 | $ 9,937 | $ 10,000 |
| C000174965 | ||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||||||||||||||||
| Account Value | 11,381 | 11,460 | 11,320 | 11,323 | 10,784 | 10,778 | 10,532 | 10,511 | 10,643 | 10,523 | 10,427 | 10,809 | 11,083 | 11,972 | 12,387 | 12,472 | 12,214 | 12,192 | 12,245 | 12,089 | 11,590 | 11,733 | 11,379 | 11,383 | 10,970 | 10,572 | 10,259 | 10,358 | 10,317 | 10,284 | 10,375 | 10,388 | 10,243 | 10,056 | 9,936 | 10,000 |
| C000174966 | ||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||||||||||||||||
| Account Value | 589,617 | 593,124 | 585,222 | 584,780 | 556,327 | 555,425 | 541,527 | 540,523 | 546,764 | 539,983 | 534,537 | 553,535 | 566,964 | 611,769 | 632,907 | 635,958 | 622,099 | 620,290 | 622,323 | 613,717 | 588,368 | 595,034 | 576,503 | 575,568 | 554,123 | 533,443 | 517,720 | 522,174 | 519,026 | 516,856 | 520,933 | 521,056 | 513,256 | 503,363 | 496,851 | 500,000 |
| Bloomberg U.S. Aggregate Bond Index | ||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||||||||||||||||
| Account Value | 11,307 | 11,340 | 11,220 | 11,235 | 10,722 | 10,717 | 10,499 | 10,471 | 10,583 | 10,372 | 10,376 | 10,597 | 10,815 | 11,489 | 11,905 | 11,977 | 11,784 | 11,801 | 12,044 | 11,987 | 11,832 | 11,640 | 11,226 | 11,258 | 10,814 | 10,422 | 10,133 | 10,218 | 10,163 | 10,102 | 10,270 | 10,327 | 10,201 | 10,051 | 9,951 | 10,000 |
| Bloomberg U.S. Aggregate Bond Index | ||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||||||||||||||||
| Account Value | 11,307 | 11,340 | 11,220 | 11,235 | 10,722 | 10,717 | 10,499 | 10,471 | 10,583 | 10,372 | 10,376 | 10,597 | 10,815 | 11,489 | 11,905 | 11,977 | 11,784 | 11,801 | 12,044 | 11,987 | 11,832 | 11,640 | 11,226 | 11,258 | 10,814 | 10,422 | 10,133 | 10,218 | 10,163 | 10,102 | 10,270 | 10,327 | 10,201 | 10,051 | 9,951 | 10,000 |
| Bloomberg U.S. Aggregate Bond Index | ||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||||||||||||||||||||||
| Account Value | $ 565,341 | $ 566,975 | $ 561,023 | $ 561,749 | $ 536,077 | $ 535,852 | $ 524,934 | $ 523,548 | $ 529,168 | $ 518,597 | $ 518,813 | $ 529,870 | $ 540,756 | $ 574,444 | $ 595,239 | $ 598,831 | $ 589,200 | $ 590,046 | $ 602,185 | $ 599,337 | $ 591,595 | $ 581,993 | $ 561,300 | $ 562,898 | $ 540,686 | $ 521,113 | $ 506,629 | $ 510,924 | $ 508,162 | $ 505,103 | $ 513,521 | $ 516,343 | $ 510,073 | $ 502,564 | $ 497,530 | $ 500,000 |