v3.26.1
Shareholder Report, Line Graph (Details) - USD ($)
 6 Months Ended 12 Months Ended 18 Months Ended 24 Months Ended 30 Months Ended 36 Months Ended 42 Months Ended 48 Months Ended 54 Months Ended 60 Months Ended 66 Months Ended 72 Months Ended 78 Months Ended 84 Months Ended 90 Months Ended 96 Months Ended 102 Months Ended 108 Months Ended 120 Months Ended
Nov. 07, 2017
Apr. 30, 2016
Apr. 30, 2018
Apr. 30, 2026
Apr. 30, 2017
Apr. 30, 2019
Apr. 30, 2018
Apr. 30, 2020
Apr. 30, 2019
Apr. 30, 2021
Apr. 30, 2020
Apr. 30, 2022
Apr. 30, 2021
Apr. 30, 2023
Apr. 30, 2022
Apr. 30, 2024
Apr. 30, 2023
Apr. 30, 2025
Apr. 30, 2024
Apr. 30, 2026
Apr. 30, 2025
Apr. 30, 2026
C000012064 [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Fund NAV                                    
Accumulated Value   $ 10,000     $ 11,512   $ 12,508   $ 13,587   $ 11,283   $ 17,212   $ 18,525   $ 18,297   $ 19,319   $ 21,561 $ 27,074
C000012097 [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Fund NAV                                    
Accumulated Value   10,000     12,097   13,144   14,765   14,746   21,615   21,165   21,538   26,587   29,799 38,987
C000012099 [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Fund NAV                                    
Accumulated Value   10,000     11,495   12,537   13,817   12,680   17,290   17,985   18,440   21,441   23,413 29,991
C000012195 [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Fund NAV                                    
Accumulated Value   10,000     12,015   13,073   13,574   10,579   17,291   18,031   17,563   20,107   21,189 27,095
C000012196 [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Fund NAV                                    
Accumulated Value   10,000     12,186   13,050   13,646   11,246   18,663   15,822   15,371   17,572   18,014 24,376
C000042588 [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Fund NAV                                    
Accumulated Value   10,000     10,602   10,265   12,197   10,416   14,316   16,007   13,632   13,880   15,966 18,947
C000099165 [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Fund NAV                                    
Accumulated Value   10,000     10,922   11,472   13,427   11,969   14,566   16,345   16,861   18,349   20,310 25,003
C000141931 [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Fund NAV                                    
Accumulated Value   10,000     11,778   13,262   15,291   14,976   21,044   21,783   22,466   25,335   27,866 34,876
C000194634 [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Fund NAV                                    
Accumulated Value $ 10,000   $ 10,216     $ 11,566   $ 10,993   $ 16,635   $ 17,252   $ 16,950   $ 19,855   $ 22,286   $ 28,457    
S And P Total Market Index [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       S&P Total Market Index                                    
Accumulated Value   10,000     11,858   13,408   15,095   14,916   22,525   21,768   22,045   26,988   30,026 39,443
Russell 3000 Index [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Russell 3000 Index                                    
Accumulated Value   10,000     11,858   13,406   15,106   14,948   22,560   21,857   22,186   27,133   30,227 39,601
Morningstar US Market Index [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Morningstar US Market Index                                    
Accumulated Value 10,000 10,000 10,333   11,840 11,677 13,398 11,612 15,142 17,424 15,057 16,914 22,594 17,180 21,933 21,104 22,277 23,534 27,366 30,820 30,517 39,965
Dow Jones U S Select Dividend Index [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Dow Jones U.S. Select Dividend Index                                    
Accumulated Value   10,000     11,560   12,611   13,751   11,456   17,568   18,974   18,816   19,947   22,340 28,175
Morningstar US Large Mid Cap Index Spliced [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Morningstar US Large-Mid Cap Index (Spliced)                                    
Accumulated Value   10,000     12,107   13,197   14,851   14,861   21,828   21,377   21,757   26,855   30,109 39,412
Morningstar US Large Mid Cap Broad Value Index Spliced [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Morningstar US Large-Mid Cap Broad Value Index (Spliced)                                    
Accumulated Value   10,000     11,523   12,602   13,923   12,810   17,505   18,216   18,683   21,723   23,728 30,407
Morningstar US Mid Cap Broad Value Index Spliced [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Morningstar US Mid Cap Broad Value Index (Spliced)                                    
Accumulated Value   10,000     12,059   13,153   13,688   10,694   17,526   18,283   17,806   20,402   21,509 27,505
Morningstar US Small Cap Extended Index Spliced [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Morningstar US Small Cap Extended Index (Spliced)                                    
Accumulated Value   10,000     12,210   13,099   13,722   11,329   18,800   15,932   15,444   17,634   18,071 24,438
FTSE Nareit Equity REITS 40 Act Capped Index Spliced [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       FTSE Nareit Equity REITS 40 Act Capped Index (Spliced)                                    
Accumulated Value   10,000     10,627   10,280   12,221   10,446   14,360   16,071   13,692   13,957   16,060 19,078
Morningstar Dividend Yield Focus Index [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Morningstar Dividend Yield Focus Index                                    
Accumulated Value   10,000     10,928   11,487   13,460   12,009   14,624   16,422   16,954   18,471   20,456 25,213
Morningstar US Dividend Growth Index [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Morningstar US Dividend Growth Index                                    
Accumulated Value   $ 10,000     $ 11,783   $ 13,275   $ 15,322   $ 15,017   $ 21,119   $ 21,879   $ 22,578   $ 25,474   $ 28,039 $ 35,129
Morningstar US Dividend and Buyback Index [Member]                                            
Account Value [Line Items]                                            
Line Graph and Table Measure Name       Morningstar US Dividend and Buyback Index                                    
Accumulated Value $ 10,000   $ 10,231     $ 11,614   $ 11,062   $ 16,790   $ 17,459   $ 17,177   $ 20,131   $ 22,616   $ 28,888