| Form N-CSR Cover | 12 Months Ended |
| Sep. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | STATE STREET INSTITUTIONAL FUNDS |
| Entity Central Index Key | 0001040061 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| Shareholder Report | 12 Months Ended |
| Sep. 30, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | STATE STREET INSTITUTIONAL FUNDS |
| Entity Central Index Key | 0001040061 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| C000004429 | |
| Shareholder Report [Line Items] | |
| Fund Name | State Street Institutional Small-Cap Equity Fund |
| Class Name | Investment |
| Trading Symbol | SIVIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the State Street Institutional Small-Cap Equity Fund (the "Fund") for the period of October 1, 2023 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund, including the Prospectus, Statement of Additional Information, financial statements and other information at www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. |
| Additional Information Phone Number | 1-800-647-7327 |
| Additional Information Website | www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf</span>" id="sjs-B20"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf</span> |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Investment $84 0.75% |
| Expenses Paid, Amount | $ 84 |
| Expense Ratio, Percent | 0.75% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year and what affected its performance? Palisade, Champlain, and SouthernSun were the primary drivers of the Fund's negative relative performance during the reporting period. Kennedy had a good year relative to the Index, outperforming by ~2.2%. Palisade, Champlain, and SouthernSun each underperformed the Index by ~2.7%, ~5.0%, and ~-1.6%, respectively for the year ending September 30, 2024. The overall Fund's lower beta/higher quality profile was a detractor for the year relative to the Index. The Fund used e-mini Russell 2000 Index futures in order to equitize cash in the liquidity sleeve of the Fund to manage daily flows and to maintain market exposure on the cash during the reporting period. The Fund’s use of e-mini Russell 2000 Index futures are meant to match the Index and not to speculate in either direction. On an individual security level, the top positive contributors to the Fund’s performance on an absolute basis during the reporting period were Dycom Industries Inc, Actuant Corporation, and Boot Barn holdings Inc. The top negative contributors to the Fund’s performance on an absolute basis during the reporting period were Darling International Inc, MGP Ingredients Inc, and Boston Beer Company, Inc. |
| Performance Past Does Not Indicate Future [Text] | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. The returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption or sale of Fund shares. Updated performance information is available by calling 1-800-647-7327 or visiting our website at <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com</span>.</span></p>" id="sjs-B25"><p style="box-sizing: border-box; color: rgb(0, 0, 0); display: block; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. The returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption or sale of Fund shares. Updated performance information is available by calling 1-800-647-7327 or visiting our website at <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com</span>.</span></p> |
| Line Graph [Table Text Block] | SIVIX S&P 500 Index Russell 2000 Index 09/30/14 $5,000,000 $5,000,000 $5,000,000 10/31/14 $5,263,975 $5,122,126 $5,329,596 11/30/14 $5,261,387 $5,259,884 $5,334,373 12/31/14 $5,327,231 $5,246,634 $5,486,403 01/31/15 $5,093,606 $5,089,134 $5,309,927 02/28/15 $5,465,676 $5,381,614 $5,625,158 03/31/15 $5,543,551 $5,296,507 $5,723,155 04/30/15 $5,442,602 $5,347,317 $5,577,199 05/31/15 $5,506,055 $5,416,080 $5,704,527 06/30/15 $5,578,162 $5,311,235 $5,747,245 07/31/15 $5,497,403 $5,422,512 $5,680,451 08/31/15 $5,194,555 $5,095,351 $5,323,487 09/30/15 $4,955,161 $4,969,274 $5,062,300 10/31/15 $5,229,166 $5,388,453 $5,347,511 11/30/15 $5,384,916 $5,404,477 $5,521,459 12/31/15 $5,124,846 $5,319,238 $5,244,228 01/31/16 $4,746,436 $5,055,275 $4,783,079 02/29/16 $4,785,582 $5,048,455 $4,782,865 03/31/16 $5,196,613 $5,390,933 $5,164,594 04/30/16 $5,330,361 $5,411,832 $5,245,650 05/31/16 $5,431,488 $5,509,018 $5,363,808 06/30/16 $5,444,537 $5,523,293 $5,360,426 07/31/16 $5,731,607 $5,726,930 $5,680,479 08/31/16 $5,855,568 $5,734,970 $5,780,934 09/30/16 $5,858,831 $5,736,055 $5,845,324 10/31/16 $5,692,461 $5,631,422 $5,567,437 11/30/16 $6,230,716 $5,839,981 $6,188,274 12/31/16 $6,366,016 $5,955,415 $6,361,667 01/31/17 $6,416,593 $6,068,368 $6,386,760 02/28/17 $6,531,236 $6,309,318 $6,510,017 03/31/17 $6,544,723 $6,316,678 $6,518,536 04/30/17 $6,642,506 $6,381,550 $6,590,021 05/31/17 $6,551,467 $6,471,356 $6,455,954 06/30/17 $6,706,571 $6,511,747 $6,679,125 07/31/17 $6,753,776 $6,645,646 $6,728,748 08/31/17 $6,642,506 $6,665,990 $6,643,144 09/30/17 $7,010,036 $6,803,497 $7,057,736 10/31/17 $7,057,241 $6,962,259 $7,117,898 11/30/17 $7,198,858 $7,175,790 $7,323,032 12/31/17 $7,198,157 $7,255,575 $7,293,475 01/31/18 $7,378,941 $7,670,986 $7,484,085 02/28/18 $7,087,473 $7,388,255 $7,194,289 03/31/18 $7,153,883 $7,200,496 $7,287,338 04/30/18 $7,238,741 $7,228,124 $7,350,339 05/31/18 $7,659,341 $7,402,192 $7,796,509 06/30/18 $7,773,714 $7,447,752 $7,852,376 07/31/18 $7,910,225 $7,724,910 $7,989,231 08/31/18 $8,205,382 $7,976,628 $8,333,647 09/30/18 $8,094,698 $8,022,031 $8,133,204 10/31/18 $7,198,157 $7,473,724 $7,249,804 11/30/18 $7,371,562 $7,626,026 $7,365,039 12/31/18 $6,500,162 $6,937,466 $6,490,176 01/31/19 $7,235,273 $7,493,405 $7,220,311 02/28/19 $7,564,959 $7,734,005 $7,595,679 03/31/19 $7,440,213 $7,884,290 $7,436,707 04/30/19 $7,760,989 $8,203,522 $7,689,336 05/31/19 $7,132,803 $7,682,204 $7,091,316 06/30/19 $7,680,795 $8,223,617 $7,592,511 07/31/19 $7,703,071 $8,341,807 $7,636,223 08/31/19 $7,328,833 $8,209,670 $7,259,191 09/30/19 $7,591,691 $8,363,277 $7,410,229 10/31/19 $7,725,347 $8,544,423 $7,605,388 11/30/19 $8,050,578 $8,854,576 $7,918,462 12/31/19 $8,232,918 $9,121,825 $8,146,787 01/31/20 $7,892,050 $9,118,249 $7,885,507 02/29/20 $7,110,893 $8,367,642 $7,221,688 03/31/20 $5,662,203 $7,334,131 $5,652,669 04/30/20 $6,471,765 $8,274,320 $6,429,088 05/31/20 $6,888,382 $8,668,410 $6,847,459 06/30/20 $7,035,145 $8,840,801 $7,089,499 07/31/20 $7,390,216 $9,339,290 $7,285,725 08/31/20 $7,716,881 $10,010,603 $7,696,227 09/30/20 $7,361,810 $9,630,234 $7,439,148 10/31/20 $7,612,727 $9,374,129 $7,594,953 11/30/20 $8,810,501 $10,400,259 $8,994,891 12/31/20 $9,481,984 $10,800,130 $9,772,953 01/31/21 $9,701,813 $10,691,094 $10,264,750 02/28/21 $10,366,187 $10,985,900 $10,904,502 03/31/21 $10,698,374 $11,467,035 $11,014,023 04/30/21 $11,050,102 $12,079,016 $11,245,306 05/31/21 $11,069,642 $12,163,380 $11,268,489 06/30/21 $11,035,446 $12,447,332 $11,486,811 07/31/21 $10,996,365 $12,743,017 $11,072,037 08/31/21 $11,201,540 $13,130,477 $11,319,700 09/30/21 $10,820,502 $12,519,781 $10,985,940 10/31/21 $11,343,208 $13,396,940 $11,453,275 11/30/21 $10,986,595 $13,304,113 $10,976,020 12/31/21 $11,465,352 $13,900,352 $11,221,206 01/31/22 $10,561,848 $13,181,050 $10,140,899 02/28/22 $10,504,664 $12,786,390 $10,249,153 03/31/22 $10,521,819 $13,261,143 $10,376,715 04/30/22 $9,715,527 $12,104,747 $9,348,286 05/31/22 $9,778,430 $12,126,954 $9,362,413 06/30/22 $9,075,069 $11,125,950 $8,592,420 07/31/22 $9,938,544 $12,151,812 $9,489,492 08/31/22 $9,658,344 $11,656,238 $9,295,311 09/30/22 $8,857,771 $10,582,715 $8,404,490 10/31/22 $9,972,855 $11,439,506 $9,329,732 11/30/22 $10,327,394 $12,078,791 $9,547,654 12/31/22 $9,744,617 $11,382,878 $8,927,989 01/31/23 $10,620,672 $12,098,109 $9,798,165 02/28/23 $10,500,665 $11,802,928 $9,632,665 03/31/23 $10,068,637 $12,236,263 $9,172,419 04/30/23 $9,888,626 $12,427,252 $9,007,513 05/31/23 $9,690,613 $12,481,269 $8,924,307 06/30/23 $10,536,667 $13,305,972 $9,649,868 07/31/23 $11,004,697 $13,733,426 $10,239,992 08/31/23 $10,602,671 $13,514,769 $9,727,703 09/30/23 $9,990,632 $12,870,413 $9,155,012 10/31/23 $9,354,592 $12,599,793 $8,530,651 11/30/23 $10,014,634 $13,750,474 $9,302,756 12/31/23 $11,117,980 $14,375,167 $10,439,400 01/31/24 $10,749,321 $14,616,731 $10,033,375 02/29/24 $11,331,414 $15,397,200 $10,600,679 03/31/24 $11,680,670 $15,892,598 $10,980,172 04/30/24 $10,982,158 $15,243,472 $10,207,359 05/31/24 $11,441,365 $15,999,315 $10,719,434 06/30/24 $11,273,205 $16,573,404 $10,620,276 07/31/24 $12,062,265 $16,775,142 $11,699,287 08/31/24 $12,172,216 $17,182,051 $11,524,525 09/30/24 $12,269,231 $17,549,010 $11,605,070 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years SIVIX 22.81% 10.08% 9.39% S&P 500 Index 36.35% 15.98% 13.38% Russell 2000 Index 26.76% 9.39% 8.79% |
| AssetsNet | $ 765,618,186 |
| Holdings Count | Holding | 328 |
| Advisory Fees Paid, Amount | $ 7,474,458 |
| InvestmentCompanyPortfolioTurnover | 38% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics as of 9/30/2024 Statistic Value Total Net Assets $765,618,186 Number of Portfolio Holdings 328 Portfolio Turnover Rate 38% Total Advisory Fees Paid $7,474,458 |
| Holdings [Text Block] | Top Ten Industry Industry % Value of Total Net Assets Regional Banks 9.1% Industrial Machinery & Supplies & Components 8.2% Application Software 6.0% Healthcare Equipment 4.5% Specialty Chemicals 3.4% Life Sciences Tools & Services 2.7% Biotechnology 2.6% Packaged Foods & Meats 2.3% Property & Casualty Insurance 2.2% Building Products 2.0% |
| Material Fund Change [Text Block] | Material Fund Changes As approved by the Board of Trustees of the Trust, Westfield Capital Management Company, L.P. became a sub-adviser to the Fund effective March 1, 2024. |
| C000004430 | |
| Shareholder Report [Line Items] | |
| Fund Name | State Street Institutional Small-Cap Equity Fund |
| Class Name | Service |
| Trading Symbol | SSQSX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the State Street Institutional Small-Cap Equity Fund (the "Fund") for the period of October 1, 2023 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund, including the Prospectus, Statement of Additional Information, financial statements and other information at www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the reporting period. |
| Additional Information Phone Number | 1-800-647-7327 |
| Additional Information Website | www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf</span>" id="sjs-B45"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf</span> |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Service $111 1.00% |
| Expenses Paid, Amount | $ 111 |
| Expense Ratio, Percent | 1% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year and what affected its performance? Palisade, Champlain, and SouthernSun were the primary drivers of the Fund's negative relative performance during the reporting period. Kennedy had a good year relative to the Index, outperforming by ~2.2%. Palisade, Champlain, and SouthernSun each underperformed the Index by ~2.7%, ~5.0%, and ~-1.6%, respectively for the year ending September 30, 2024. The overall Fund's lower beta/higher quality profile was a detractor for the year relative to the Index. The Fund used e-mini Russell 2000 Index futures in order to equitize cash in the liquidity sleeve of the Fund to manage daily flows and to maintain market exposure on the cash during the reporting period. The Fund’s use of e-mini Russell 2000 Index futures are meant to match the Index and not to speculate in either direction. On an individual security level, the top positive contributors to the Fund’s performance on an absolute basis during the reporting period were Dycom Industries Inc, Actuant Corporation, and Boot Barn holdings Inc. The top negative contributors to the Fund’s performance on an absolute basis during the reporting period were Darling International Inc, MGP Ingredients Inc, and Boston Beer Company, Inc. |
| Performance Past Does Not Indicate Future [Text] | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. The returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption or sale of Fund shares. Updated performance information is available by calling 1-800-647-7327 or visiting our website at <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com</span>.</span></p>" id="sjs-B50"><p style="box-sizing: border-box; color: rgb(0, 0, 0); display: block; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. The returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption or sale of Fund shares. Updated performance information is available by calling 1-800-647-7327 or visiting our website at <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com</span>.</span></p> |
| Line Graph [Table Text Block] | SSQSX S&P 500 Index Russell 2000 Index 09/30/14 $5,000,000 $5,000,000 $5,000,000 10/31/14 $5,263,294 $5,122,126 $5,329,596 11/30/14 $5,258,131 $5,259,884 $5,334,373 12/31/14 $5,323,043 $5,246,634 $5,486,403 01/31/15 $5,090,357 $5,089,134 $5,309,927 02/28/15 $5,460,931 $5,381,614 $5,625,158 03/31/15 $5,538,493 $5,296,507 $5,723,155 04/30/15 $5,435,077 $5,347,317 $5,577,199 05/31/15 $5,498,276 $5,416,080 $5,704,527 06/30/15 $5,567,219 $5,311,235 $5,747,245 07/31/15 $5,486,785 $5,422,512 $5,680,451 08/31/15 $5,182,283 $5,095,351 $5,323,487 09/30/15 $4,943,852 $4,969,274 $5,062,300 10/31/15 $5,213,882 $5,388,453 $5,347,511 11/30/15 $5,369,006 $5,404,477 $5,521,459 12/31/15 $5,111,619 $5,319,238 $5,244,228 01/31/16 $4,732,139 $5,055,275 $4,783,079 02/29/16 $4,767,817 $5,048,455 $4,782,865 03/31/16 $5,176,487 $5,390,933 $5,164,594 04/30/16 $5,309,467 $5,411,832 $5,245,650 05/31/16 $5,406,769 $5,509,018 $5,363,808 06/30/16 $5,422,986 $5,523,293 $5,360,426 07/31/16 $5,708,407 $5,726,930 $5,680,479 08/31/16 $5,828,413 $5,734,970 $5,780,934 09/30/16 $5,831,656 $5,736,055 $5,845,324 10/31/16 $5,662,999 $5,631,422 $5,567,437 11/30/16 $6,198,162 $5,839,981 $6,188,274 12/31/16 $6,332,632 $5,955,415 $6,361,667 01/31/17 $6,379,491 $6,068,368 $6,386,760 02/28/17 $6,493,291 $6,309,318 $6,510,017 03/31/17 $6,506,679 $6,316,678 $6,518,536 04/30/17 $6,600,397 $6,381,550 $6,590,021 05/31/17 $6,510,027 $6,471,356 $6,455,954 06/30/17 $6,660,644 $6,511,747 $6,679,125 07/31/17 $6,707,503 $6,645,646 $6,728,748 08/31/17 $6,593,703 $6,665,990 $6,643,144 09/30/17 $6,961,879 $6,803,497 $7,057,736 10/31/17 $7,005,391 $6,962,259 $7,117,898 11/30/17 $7,142,620 $7,175,790 $7,323,032 12/31/17 $7,142,373 $7,255,575 $7,293,475 01/31/18 $7,321,481 $7,670,986 $7,484,085 02/28/18 $7,029,060 $7,388,255 $7,194,289 03/31/18 $7,091,200 $7,200,496 $7,287,338 04/30/18 $7,175,271 $7,228,124 $7,350,339 05/31/18 $7,591,970 $7,402,192 $7,796,509 06/30/18 $7,701,628 $7,447,752 $7,852,376 07/31/18 $7,836,872 $7,724,910 $7,989,231 08/31/18 $8,125,638 $7,976,628 $8,333,647 09/30/18 $8,015,980 $8,022,031 $8,133,204 10/31/18 $7,127,752 $7,473,724 $7,249,804 11/30/18 $7,299,549 $7,626,026 $7,365,039 12/31/18 $6,433,296 $6,937,466 $6,490,176 01/31/19 $7,160,347 $7,493,405 $7,220,311 02/28/19 $7,482,012 $7,734,005 $7,595,679 03/31/19 $7,358,634 $7,884,290 $7,436,707 04/30/19 $7,675,892 $8,203,522 $7,689,336 05/31/19 $7,050,188 $7,682,204 $7,091,316 06/30/19 $7,592,171 $8,223,617 $7,592,511 07/31/19 $7,609,797 $8,341,807 $7,636,223 08/31/19 $7,239,662 $8,209,670 $7,259,191 09/30/19 $7,499,637 $8,363,277 $7,410,229 10/31/19 $7,631,828 $8,544,423 $7,605,388 11/30/19 $7,949,087 $8,854,576 $7,918,462 12/31/19 $8,129,924 $9,121,825 $8,146,787 01/31/20 $7,789,037 $9,118,249 $7,885,507 02/29/20 $7,013,869 $8,367,642 $7,221,688 03/31/20 $5,589,615 $7,334,131 $5,652,669 04/30/20 $6,383,461 $8,274,320 $6,429,088 05/31/20 $6,794,394 $8,668,410 $6,847,459 06/30/20 $6,934,484 $8,840,801 $7,089,499 07/31/20 $7,284,711 $9,339,290 $7,285,725 08/31/20 $7,606,919 $10,010,603 $7,696,227 09/30/20 $7,252,023 $9,630,234 $7,439,148 10/31/20 $7,499,516 $9,374,129 $7,594,953 11/30/20 $8,676,277 $10,400,259 $8,994,891 12/31/20 $9,337,954 $10,800,130 $9,772,953 01/31/21 $9,549,525 $10,691,094 $10,264,750 02/28/21 $10,203,470 $10,985,900 $10,904,502 03/31/21 $10,530,443 $11,467,035 $11,014,023 04/30/21 $10,871,841 $12,079,016 $11,245,306 05/31/21 $10,886,266 $12,163,380 $11,268,489 06/30/21 $10,852,607 $12,447,332 $11,486,811 07/31/21 $10,814,140 $12,743,017 $11,072,037 08/31/21 $11,011,285 $13,130,477 $11,319,700 09/30/21 $10,631,420 $12,519,781 $10,985,940 10/31/21 $11,145,921 $13,396,940 $11,453,275 11/30/21 $10,794,906 $13,304,113 $10,976,020 12/31/21 $11,262,939 $13,900,352 $11,221,206 01/31/22 $10,368,876 $13,181,050 $10,140,899 02/28/22 $10,312,646 $12,786,390 $10,249,153 03/31/22 $10,323,892 $13,261,143 $10,376,715 04/30/22 $9,531,044 $12,104,747 $9,348,286 05/31/22 $9,592,897 $12,126,954 $9,362,413 06/30/22 $8,901,264 $11,125,950 $8,592,420 07/31/22 $9,744,719 $12,151,812 $9,489,492 08/31/22 $9,474,814 $11,656,238 $9,295,311 09/30/22 $8,687,589 $10,582,715 $8,404,490 10/31/22 $9,772,834 $11,439,506 $9,329,732 11/30/22 $10,121,463 $12,078,791 $9,547,654 12/31/22 $9,542,369 $11,382,878 $8,927,989 01/31/23 $10,401,830 $12,098,109 $9,798,165 02/28/23 $10,284,096 $11,802,928 $9,632,665 03/31/23 $9,854,365 $12,236,263 $9,172,419 04/30/23 $9,683,650 $12,427,252 $9,007,513 05/31/23 $9,483,502 $12,481,269 $8,924,307 06/30/23 $10,307,642 $13,305,972 $9,649,868 07/31/23 $10,760,920 $13,733,426 $10,239,992 08/31/23 $10,366,510 $13,514,769 $9,727,703 09/30/23 $9,766,064 $12,870,413 $9,155,012 10/31/23 $9,142,072 $12,599,793 $8,530,651 11/30/23 $9,789,611 $13,750,474 $9,302,756 12/31/23 $10,864,774 $14,375,167 $10,439,400 01/31/24 $10,503,881 $14,616,731 $10,033,375 02/29/24 $11,067,381 $15,397,200 $10,600,679 03/31/24 $11,409,279 $15,892,598 $10,980,172 04/30/24 $10,725,482 $15,243,472 $10,207,359 05/31/24 $11,168,684 $15,999,315 $10,719,434 06/30/24 $11,004,066 $16,573,404 $10,620,276 07/31/24 $11,776,504 $16,775,142 $11,699,287 08/31/24 $11,877,807 $17,182,051 $11,524,525 09/30/24 $11,966,447 $17,549,010 $11,605,070 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years SSQSX 22.53% 9.80% 9.12% S&P 500 Index 36.35% 15.98% 13.38% Russell 2000 Index 26.76% 9.39% 8.79% |
| AssetsNet | $ 765,618,186 |
| Holdings Count | Holding | 328 |
| Advisory Fees Paid, Amount | $ 7,474,458 |
| InvestmentCompanyPortfolioTurnover | 38% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics as of 9/30/2024 Statistic Value Total Net Assets $765,618,186 Number of Portfolio Holdings 328 Portfolio Turnover Rate 38% Total Advisory Fees Paid $7,474,458 |
| Holdings [Text Block] | Top Ten Industry Industry % Value of Total Net Assets Regional Banks 9.1% Industrial Machinery & Supplies & Components 8.2% Application Software 6.0% Healthcare Equipment 4.5% Specialty Chemicals 3.4% Life Sciences Tools & Services 2.7% Biotechnology 2.6% Packaged Foods & Meats 2.3% Property & Casualty Insurance 2.2% Building Products 2.0% |
| Material Fund Change [Text Block] | Material Fund Changes As approved by the Board of Trustees of the Trust, Westfield Capital Management Company, L.P. became a sub-adviser to the Fund effective March 1, 2024. |
| C000004434 | |
| Shareholder Report [Line Items] | |
| Fund Name | State Street Institutional U.S. Equity Fund |
| Class Name | Investment |
| Trading Symbol | SUSIX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the State Street Institutional U.S. Equity Fund (the "Fund") for the period of October 1, 2023 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund, including the Prospectus, Statement of Additional Information, financial statements and other information at www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf |
| Additional Information Phone Number | 1-800-647-7327 |
| Additional Information Website | www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf</span>" id="sjs-B69"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf</span> |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Investment $47 0.39% |
| Expenses Paid, Amount | $ 47 |
| Expense Ratio, Percent | 0.39% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year and what affected its performance? IT was the best performing Index sector during the reporting period rising 52.7%. This was driven largely by “Magnificent 7”, top Index names which rose significantly largely on artificial intelligence excitement. The Fund also outperformed by more than 10% in the sector, driven by semiconductor company exposures such as Nvidia. The Fund benefitted from holdings including United Rentals, Parker-Hannifin, Trane Technologies, and Eaton, all of which returned more than 50% during the reporting period, as they benefitted from a range of tailwinds including infrastructure/capex spending driven by reshoring, green investment, and increased data center demand. The healthcare sector, which is more defensive, lagged in the strong risk-on market (although was still up 14.8%). This negatively impacted the Fund, which was modestly overweight the sector. In addition, the Fund’s stock selections underperformed. The largest detracting positions included Humana (healthcare services), Biomarin Pharma (biotech), and Merck (pharma). Derivatives did not have a material impact on performance. |
| Performance Past Does Not Indicate Future [Text] | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. The returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption or sale of Fund shares. Updated performance information is available by calling 1-800-647-7327 or visiting our website at <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com</span>.</span></p>" id="sjs-B74"><p style="box-sizing: border-box; color: rgb(0, 0, 0); display: block; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. The returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption or sale of Fund shares. Updated performance information is available by calling 1-800-647-7327 or visiting our website at <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com</span>.</span></p> |
| Line Graph [Table Text Block] | SUSIX S&P 500 Index 09/30/14 $5,000,000 $5,000,000 10/31/14 $5,092,379 $5,122,126 11/30/14 $5,225,173 $5,259,884 12/31/14 $5,201,741 $5,246,634 01/31/15 $4,985,001 $5,089,134 02/28/15 $5,298,440 $5,381,614 03/31/15 $5,231,751 $5,296,507 04/30/15 $5,271,764 $5,347,317 05/31/15 $5,335,119 $5,416,080 06/30/15 $5,255,092 $5,311,235 07/31/15 $5,398,473 $5,422,512 08/31/15 $5,035,018 $5,095,351 09/30/15 $4,821,613 $4,969,274 10/31/15 $5,251,757 $5,388,453 11/30/15 $5,238,420 $5,404,477 12/31/15 $5,102,160 $5,319,238 01/31/16 $4,770,378 $5,055,275 02/29/16 $4,758,239 $5,048,455 03/31/16 $5,057,652 $5,390,933 04/30/16 $5,102,160 $5,411,832 05/31/16 $5,235,682 $5,509,018 06/30/16 $5,170,944 $5,523,293 07/31/16 $5,385,388 $5,726,930 08/31/16 $5,429,896 $5,734,970 09/30/16 $5,462,265 $5,736,055 10/31/16 $5,340,881 $5,631,422 11/30/16 $5,510,818 $5,839,981 12/31/16 $5,605,349 $5,955,415 01/31/17 $5,769,576 $6,068,368 02/28/17 $5,998,631 $6,309,318 03/31/17 $6,033,205 $6,316,678 04/30/17 $6,119,641 $6,381,550 05/31/17 $6,145,571 $6,471,356 06/30/17 $6,201,755 $6,511,747 07/31/17 $6,348,695 $6,645,646 08/31/17 $6,357,339 $6,665,990 09/30/17 $6,461,061 $6,803,497 10/31/17 $6,582,071 $6,962,259 11/30/17 $6,716,046 $7,175,790 12/31/17 $6,751,760 $7,255,575 01/31/18 $7,135,695 $7,670,986 02/28/18 $6,916,304 $7,388,255 03/31/18 $6,762,730 $7,200,496 04/30/18 $6,757,245 $7,228,124 05/31/18 $6,916,304 $7,402,192 06/30/18 $6,982,121 $7,447,752 07/31/18 $7,272,814 $7,724,910 08/31/18 $7,459,296 $7,976,628 09/30/18 $7,541,568 $8,022,031 10/31/18 $7,004,060 $7,473,724 11/30/18 $7,185,058 $7,626,026 12/31/18 $6,544,944 $6,937,466 01/31/19 $7,088,756 $7,493,405 02/28/19 $7,267,894 $7,734,005 03/31/19 $7,421,442 $7,884,290 04/30/19 $7,754,127 $8,203,522 05/31/19 $7,274,292 $7,682,204 06/30/19 $7,837,298 $8,223,617 07/31/19 $7,920,470 $8,341,807 08/31/19 $7,773,320 $8,209,670 09/30/19 $7,875,685 $8,363,277 10/31/19 $8,093,210 $8,544,423 11/30/19 $8,393,906 $8,854,576 12/31/19 $8,660,546 $9,121,825 01/31/20 $8,694,589 $9,118,249 02/29/20 $8,054,580 $8,367,642 03/31/20 $7,121,801 $7,334,131 04/30/20 $8,068,198 $8,274,320 05/31/20 $8,497,140 $8,668,410 06/30/20 $8,640,120 $8,840,801 07/31/20 $9,184,809 $9,339,290 08/31/20 $9,899,712 $10,010,603 09/30/20 $9,511,622 $9,630,234 10/31/20 $9,320,981 $9,374,129 11/30/20 $10,280,994 $10,400,259 12/31/20 $10,654,830 $10,800,130 01/31/21 $10,490,800 $10,691,094 02/28/21 $10,840,256 $10,985,900 03/31/21 $11,303,819 $11,467,035 04/30/21 $11,959,940 $12,079,016 05/31/21 $12,059,784 $12,163,380 06/30/21 $12,309,395 $12,447,332 07/31/21 $12,608,929 $12,743,017 08/31/21 $12,879,935 $13,130,477 09/30/21 $12,309,395 $12,519,781 10/31/21 $13,115,283 $13,396,940 11/30/21 $12,901,330 $13,304,113 12/31/21 $13,438,564 $13,900,352 01/31/22 $12,903,295 $13,181,050 02/28/22 $12,431,223 $12,786,390 03/31/22 $12,724,957 $13,261,143 04/30/22 $11,633,947 $12,104,747 05/31/22 $11,654,927 $12,126,954 06/30/22 $10,731,765 $11,125,950 07/31/22 $11,749,342 $12,151,812 08/31/22 $11,266,780 $11,656,238 09/30/22 $10,217,731 $10,582,715 10/31/22 $10,952,065 $11,439,506 11/30/22 $11,581,494 $12,078,791 12/31/22 $10,951,698 $11,382,878 01/31/23 $11,702,320 $12,098,109 02/28/23 $11,357,772 $11,802,928 03/31/23 $11,690,014 $12,236,263 04/30/23 $11,923,815 $12,427,252 05/31/23 $12,108,394 $12,481,269 06/30/23 $12,871,321 $13,305,972 07/31/23 $13,265,090 $13,733,426 08/31/23 $13,129,732 $13,514,769 09/30/23 $12,502,163 $12,870,413 10/31/23 $12,342,194 $12,599,793 11/30/23 $13,486,585 $13,750,474 12/31/23 $14,085,973 $14,375,167 01/31/24 $14,411,227 $14,616,731 02/29/24 $15,349,457 $15,397,200 03/31/24 $15,837,337 $15,892,598 04/30/24 $15,186,831 $15,243,472 05/31/24 $15,899,886 $15,999,315 06/30/24 $16,525,373 $16,573,404 07/31/24 $16,688,000 $16,775,142 08/31/24 $17,088,312 $17,182,051 09/30/24 $17,363,526 $17,549,010 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years SUSIX 38.88% 17.13% 13.26% S&P 500 Index 36.35% 15.98% 13.38% |
| AssetsNet | $ 301,897,466 |
| Holdings Count | Holding | 97 |
| Advisory Fees Paid, Amount | $ 985,160 |
| InvestmentCompanyPortfolioTurnover | 58% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics as of 9/30/2024 Statistic Value Total Net Assets $301,897,466 Number of Portfolio Holdings 97 Portfolio Turnover Rate 58% Total Advisory Fees Paid $985,160 |
| Holdings [Text Block] | Top Ten Industry Industry % Value of Total Net Assets Semiconductors 11.4% Systems Software 8.3% Interactive Media & Services 7.8% Technology Hardware, Storage & Peripherals 6.1% Pharmaceuticals 5.0% Broadline Retail 4.2% Transaction & Payment Processing Services 3.6% Healthcare Equipment 2.8% Application Software 2.8% Diversified Banks 2.6% |
| Material Fund Change [Text Block] | |
| C000004433 | |
| Shareholder Report [Line Items] | |
| Fund Name | State Street Institutional U.S. Equity Fund |
| Class Name | Service |
| Trading Symbol | SUSSX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the State Street Institutional U.S. Equity Fund (the "Fund") for the period of October 1, 2023 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | Annual Shareholder Report |
| Additional Information [Text Block] | You can find additional information about the Fund, including the Prospectus, Statement of Additional Information, financial statements and other information at www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf |
| Additional Information Phone Number | 1-800-647-7327 |
| Additional Information Website | www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf</span>" id="sjs-B93"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com/us/en/individual/fund-finder?tab=documents&type=mf</span> |
| Expenses [Text Block] | What were the Fund costs for the last year? (based on a hypothetical $10,000 investment) Class Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Service $76 0.64% |
| Expenses Paid, Amount | $ 76 |
| Expense Ratio, Percent | 0.64% |
| Factors Affecting Performance [Text Block] | How did the Fund perform last year and what affected its performance? IT was the best performing Index sector during the reporting period rising 52.7%. This was driven largely by “Magnificent 7”, top Index names which rose significantly largely on artificial intelligence excitement. The Fund also outperformed by more than 10% in the sector, driven by semiconductor company exposures such as Nvidia. The Fund benefitted from holdings including United Rentals, Parker-Hannifin, Trane Technologies, and Eaton, all of which returned more than 50% during the reporting period, as they benefitted from a range of tailwinds including infrastructure/capex spending driven by reshoring, green investment, and increased data center demand. The healthcare sector, which is more defensive, lagged in the strong risk-on market (although was still up 14.8%). This negatively impacted the Fund, which was modestly overweight the sector. In addition, the Fund’s stock selections underperformed. The largest detracting positions included Humana (healthcare services), Biomarin Pharma (biotech), and Merck (pharma). Derivatives did not have a material impact on performance. |
| Performance Past Does Not Indicate Future [Text] | <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. The returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption or sale of Fund shares. Updated performance information is available by calling 1-800-647-7327 or visiting our website at <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com</span>.</span></p>" id="sjs-B98"><p style="box-sizing: border-box; color: rgb(0, 0, 0); display: block; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;"><span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future. The returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or on the redemption or sale of Fund shares. Updated performance information is available by calling 1-800-647-7327 or visiting our website at <span style="font-weight: 700; box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left;">www.ssga.com</span>.</span></p> |
| Line Graph [Table Text Block] | SUSSX S&P 500 Index 09/30/14 $5,000,000 $5,000,000 10/31/14 $5,091,922 $5,122,126 11/30/14 $5,222,841 $5,259,884 12/31/14 $5,198,136 $5,246,634 01/31/15 $4,981,015 $5,089,134 02/28/15 $5,293,924 $5,381,614 03/31/15 $5,223,679 $5,296,507 04/30/15 $5,261,995 $5,347,317 05/31/15 $5,325,854 $5,416,080 06/30/15 $5,242,837 $5,311,235 07/31/15 $5,386,520 $5,422,512 08/31/15 $5,022,523 $5,095,351 09/30/15 $4,808,595 $4,969,274 10/31/15 $5,236,451 $5,388,453 11/30/15 $5,220,486 $5,404,477 12/31/15 $5,087,132 $5,319,238 01/31/16 $4,753,864 $5,055,275 02/29/16 $4,742,372 $5,048,455 03/31/16 $5,037,333 $5,390,933 04/30/16 $5,079,471 $5,411,832 05/31/16 $5,209,714 $5,509,018 06/30/16 $5,148,423 $5,523,293 07/31/16 $5,359,110 $5,726,930 08/31/16 $5,401,247 $5,734,970 09/30/16 $5,431,893 $5,736,055 10/31/16 $5,313,142 $5,631,422 11/30/16 $5,481,691 $5,839,981 12/31/16 $5,571,744 $5,955,415 01/31/17 $5,734,423 $6,068,368 02/28/17 $5,962,173 $6,309,318 03/31/17 $5,994,709 $6,316,678 04/30/17 $6,076,048 $6,381,550 05/31/17 $6,104,517 $6,471,356 06/30/17 $6,157,388 $6,511,747 07/31/17 $6,303,798 $6,645,646 08/31/17 $6,311,932 $6,665,990 09/30/17 $6,413,606 $6,803,497 10/31/17 $6,531,549 $6,962,259 11/30/17 $6,665,758 $7,175,790 12/31/17 $6,695,964 $7,255,575 01/31/18 $7,076,705 $7,670,986 02/28/18 $6,858,413 $7,388,255 03/31/18 $6,706,117 $7,200,496 04/30/18 $6,701,040 $7,228,124 05/31/18 $6,853,337 $7,402,192 06/30/18 $6,914,255 $7,447,752 07/31/18 $7,203,619 $7,724,910 08/31/18 $7,386,374 $7,976,628 09/30/18 $7,462,522 $8,022,031 10/31/18 $6,929,485 $7,473,724 11/30/18 $7,107,164 $7,626,026 12/31/18 $6,476,086 $6,937,466 01/31/19 $7,007,487 $7,493,405 02/28/19 $7,188,514 $7,734,005 03/31/19 $7,340,343 $7,884,290 04/30/19 $7,667,359 $8,203,522 05/31/19 $7,194,353 $7,682,204 06/30/19 $7,743,273 $8,223,617 07/31/19 $7,825,027 $8,341,807 08/31/19 $7,679,038 $8,209,670 09/30/19 $7,778,311 $8,363,277 10/31/19 $7,994,375 $8,544,423 11/30/19 $8,286,353 $8,854,576 12/31/19 $8,548,853 $9,121,825 01/31/20 $8,579,671 $9,118,249 02/29/20 $7,944,825 $8,367,642 03/31/20 $7,026,455 $7,334,131 04/30/20 $7,957,152 $8,274,320 05/31/20 $8,382,437 $8,668,410 06/30/20 $8,524,199 $8,840,801 07/31/20 $9,054,265 $9,339,290 08/31/20 $9,756,911 $10,010,603 09/30/20 $9,374,770 $9,630,234 10/31/20 $9,183,700 $9,374,129 11/30/20 $10,132,888 $10,400,259 12/31/20 $10,498,434 $10,800,130 01/31/21 $10,331,588 $10,691,094 02/28/21 $10,671,696 $10,985,900 03/31/21 $11,127,313 $11,467,035 04/30/21 $11,769,027 $12,079,016 05/31/21 $11,865,284 $12,163,380 06/30/21 $12,109,135 $12,447,332 07/31/21 $12,404,323 $12,743,017 08/31/21 $12,667,426 $13,130,477 09/30/21 $12,102,718 $12,519,781 10/31/21 $12,892,025 $13,396,940 11/30/21 $12,673,843 $13,304,113 12/31/21 $13,202,710 $13,900,352 01/31/22 $12,677,482 $13,181,050 02/28/22 $12,225,038 $12,786,390 03/31/22 $12,505,554 $13,261,143 04/30/22 $11,428,737 $12,104,747 05/31/22 $11,446,834 $12,126,954 06/30/22 $10,532,898 $11,125,950 07/31/22 $11,537,323 $12,151,812 08/31/22 $11,057,733 $11,656,238 09/30/22 $10,026,160 $10,582,715 10/31/22 $10,750,071 $11,439,506 11/30/22 $11,365,395 $12,078,791 12/31/22 $10,749,012 $11,382,878 01/31/23 $11,474,596 $12,098,109 02/28/23 $11,132,535 $11,802,928 03/31/23 $11,464,231 $12,236,263 04/30/23 $11,692,271 $12,427,252 05/31/23 $11,868,485 $12,481,269 06/30/23 $12,604,434 $13,305,972 07/31/23 $12,987,957 $13,733,426 08/31/23 $12,853,206 $13,514,769 09/30/23 $12,231,277 $12,870,413 10/31/23 $12,086,160 $12,599,793 11/30/23 $13,195,267 $13,750,474 12/31/23 $13,786,782 $14,375,167 01/31/24 $14,101,310 $14,616,731 02/29/24 $15,013,439 $15,397,200 03/31/24 $15,485,230 $15,892,598 04/30/24 $14,845,691 $15,243,472 05/31/24 $15,548,136 $15,999,315 06/30/24 $16,156,222 $16,573,404 07/31/24 $16,303,001 $16,775,142 08/31/24 $16,690,918 $17,182,051 09/30/24 $16,953,025 $17,549,010 |
| Average Annual Return [Table Text Block] | Name 1 Year 5 Years 10 Years SUSSX 38.60% 16.86% 12.99% S&P 500 Index 36.35% 15.98% 13.38% |
| AssetsNet | $ 301,897,466 |
| Holdings Count | Holding | 97 |
| Advisory Fees Paid, Amount | $ 985,160 |
| InvestmentCompanyPortfolioTurnover | 58% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics as of 9/30/2024 Statistic Value Total Net Assets $301,897,466 Number of Portfolio Holdings 97 Portfolio Turnover Rate 58% Total Advisory Fees Paid $985,160 |
| Holdings [Text Block] | Top Ten Industry Industry % Value of Total Net Assets Semiconductors 11.4% Systems Software 8.3% Interactive Media & Services 7.8% Technology Hardware, Storage & Peripherals 6.1% Pharmaceuticals 5.0% Broadline Retail 4.2% Transaction & Payment Processing Services 3.6% Healthcare Equipment 2.8% Application Software 2.8% Diversified Banks 2.6% |
| Material Fund Change [Text Block] |
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Sep. 30, 2024 | Aug. 31, 2024 | Jul. 31, 2024 | Jun. 30, 2024 | May 31, 2024 | Apr. 30, 2024 | Mar. 31, 2024 | Feb. 29, 2024 | Jan. 31, 2024 | Dec. 31, 2023 | Nov. 30, 2023 | Oct. 31, 2023 | Sep. 30, 2023 | Aug. 31, 2023 | Jul. 31, 2023 | Jun. 30, 2023 | May 31, 2023 | Apr. 30, 2023 | Mar. 31, 2023 | Feb. 28, 2023 | Jan. 31, 2023 | Dec. 31, 2022 | Nov. 30, 2022 | Oct. 31, 2022 | Sep. 30, 2022 | Aug. 31, 2022 | Jul. 31, 2022 | Jun. 30, 2022 | May 31, 2022 | Apr. 30, 2022 | Mar. 31, 2022 | Feb. 28, 2022 | Jan. 31, 2022 | Dec. 31, 2021 | Nov. 30, 2021 | Oct. 31, 2021 | Sep. 30, 2021 | Aug. 31, 2021 | Jul. 31, 2021 | Jun. 30, 2021 | May 31, 2021 | Apr. 30, 2021 | Mar. 31, 2021 | Feb. 28, 2021 | Jan. 31, 2021 | Dec. 31, 2020 | Nov. 30, 2020 | Oct. 31, 2020 | Sep. 30, 2020 | Aug. 31, 2020 | Jul. 31, 2020 | Jun. 30, 2020 | May 31, 2020 | Apr. 30, 2020 | Mar. 31, 2020 | Feb. 29, 2020 | Jan. 31, 2020 | Dec. 31, 2019 | Nov. 30, 2019 | Oct. 31, 2019 | Sep. 30, 2019 | Aug. 31, 2019 | Jul. 31, 2019 | Jun. 30, 2019 | May 31, 2019 | Apr. 30, 2019 | Mar. 31, 2019 | Feb. 28, 2019 | Jan. 31, 2019 | Dec. 31, 2018 | Nov. 30, 2018 | Oct. 31, 2018 | Sep. 30, 2018 | Aug. 31, 2018 | Jul. 31, 2018 | Jun. 30, 2018 | May 31, 2018 | Apr. 30, 2018 | Mar. 31, 2018 | Feb. 28, 2018 | Jan. 31, 2018 | Dec. 31, 2017 | Nov. 30, 2017 | Oct. 31, 2017 | Sep. 30, 2017 | Aug. 31, 2017 | Jul. 31, 2017 | Jun. 30, 2017 | May 31, 2017 | Apr. 30, 2017 | Mar. 31, 2017 | Feb. 28, 2017 | Jan. 31, 2017 | Dec. 31, 2016 | Nov. 30, 2016 | Oct. 31, 2016 | Sep. 30, 2016 | Aug. 31, 2016 | Jul. 31, 2016 | Jun. 30, 2016 | May 31, 2016 | Apr. 30, 2016 | Mar. 31, 2016 | Feb. 29, 2016 | Jan. 31, 2016 | Dec. 31, 2015 | Nov. 30, 2015 | Oct. 31, 2015 | Sep. 30, 2015 | Aug. 31, 2015 | Jul. 31, 2015 | Jun. 30, 2015 | May 31, 2015 | Apr. 30, 2015 | Mar. 31, 2015 | Feb. 28, 2015 | Jan. 31, 2015 | Dec. 31, 2014 | Nov. 30, 2014 | Oct. 31, 2014 | Sep. 30, 2014 | |
| C000004429 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | SIVIX | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 12,269,231 | $ 12,172,216 | $ 12,062,265 | $ 11,273,205 | $ 11,441,365 | $ 10,982,158 | $ 11,680,670 | $ 11,331,414 | $ 10,749,321 | $ 11,117,980 | $ 10,014,634 | $ 9,354,592 | $ 9,990,632 | $ 10,602,671 | $ 11,004,697 | $ 10,536,667 | $ 9,690,613 | $ 9,888,626 | $ 10,068,637 | $ 10,500,665 | $ 10,620,672 | $ 9,744,617 | $ 10,327,394 | $ 9,972,855 | $ 8,857,771 | $ 9,658,344 | $ 9,938,544 | $ 9,075,069 | $ 9,778,430 | $ 9,715,527 | $ 10,521,819 | $ 10,504,664 | $ 10,561,848 | $ 11,465,352 | $ 10,986,595 | $ 11,343,208 | $ 10,820,502 | $ 11,201,540 | $ 10,996,365 | $ 11,035,446 | $ 11,069,642 | $ 11,050,102 | $ 10,698,374 | $ 10,366,187 | $ 9,701,813 | $ 9,481,984 | $ 8,810,501 | $ 7,612,727 | $ 7,361,810 | $ 7,716,881 | $ 7,390,216 | $ 7,035,145 | $ 6,888,382 | $ 6,471,765 | $ 5,662,203 | $ 7,110,893 | $ 7,892,050 | $ 8,232,918 | $ 8,050,578 | $ 7,725,347 | $ 7,591,691 | $ 7,328,833 | $ 7,703,071 | $ 7,680,795 | $ 7,132,803 | $ 7,760,989 | $ 7,440,213 | $ 7,564,959 | $ 7,235,273 | $ 6,500,162 | $ 7,371,562 | $ 7,198,157 | $ 8,094,698 | $ 8,205,382 | $ 7,910,225 | $ 7,773,714 | $ 7,659,341 | $ 7,238,741 | $ 7,153,883 | $ 7,087,473 | $ 7,378,941 | $ 7,198,157 | $ 7,198,858 | $ 7,057,241 | $ 7,010,036 | $ 6,642,506 | $ 6,753,776 | $ 6,706,571 | $ 6,551,467 | $ 6,642,506 | $ 6,544,723 | $ 6,531,236 | $ 6,416,593 | $ 6,366,016 | $ 6,230,716 | $ 5,692,461 | $ 5,858,831 | $ 5,855,568 | $ 5,731,607 | $ 5,444,537 | $ 5,431,488 | $ 5,330,361 | $ 5,196,613 | $ 4,785,582 | $ 4,746,436 | $ 5,124,846 | $ 5,384,916 | $ 5,229,166 | $ 4,955,161 | $ 5,194,555 | $ 5,497,403 | $ 5,578,162 | $ 5,506,055 | $ 5,442,602 | $ 5,543,551 | $ 5,465,676 | $ 5,093,606 | $ 5,327,231 | $ 5,261,387 | $ 5,263,975 | $ 5,000,000 |
| C000004430 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | SSQSX | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 11,966,447 | 11,877,807 | 11,776,504 | 11,004,066 | 11,168,684 | 10,725,482 | 11,409,279 | 11,067,381 | 10,503,881 | 10,864,774 | 9,789,611 | 9,142,072 | 9,766,064 | 10,366,510 | 10,760,920 | 10,307,642 | 9,483,502 | 9,683,650 | 9,854,365 | 10,284,096 | 10,401,830 | 9,542,369 | 10,121,463 | 9,772,834 | 8,687,589 | 9,474,814 | 9,744,719 | 8,901,264 | 9,592,897 | 9,531,044 | 10,323,892 | 10,312,646 | 10,368,876 | 11,262,939 | 10,794,906 | 11,145,921 | 10,631,420 | 11,011,285 | 10,814,140 | 10,852,607 | 10,886,266 | 10,871,841 | 10,530,443 | 10,203,470 | 9,549,525 | 9,337,954 | 8,676,277 | 7,499,516 | 7,252,023 | 7,606,919 | 7,284,711 | 6,934,484 | 6,794,394 | 6,383,461 | 5,589,615 | 7,013,869 | 7,789,037 | 8,129,924 | 7,949,087 | 7,631,828 | 7,499,637 | 7,239,662 | 7,609,797 | 7,592,171 | 7,050,188 | 7,675,892 | 7,358,634 | 7,482,012 | 7,160,347 | 6,433,296 | 7,299,549 | 7,127,752 | 8,015,980 | 8,125,638 | 7,836,872 | 7,701,628 | 7,591,970 | 7,175,271 | 7,091,200 | 7,029,060 | 7,321,481 | 7,142,373 | 7,142,620 | 7,005,391 | 6,961,879 | 6,593,703 | 6,707,503 | 6,660,644 | 6,510,027 | 6,600,397 | 6,506,679 | 6,493,291 | 6,379,491 | 6,332,632 | 6,198,162 | 5,662,999 | 5,831,656 | 5,828,413 | 5,708,407 | 5,422,986 | 5,406,769 | 5,309,467 | 5,176,487 | 4,767,817 | 4,732,139 | 5,111,619 | 5,369,006 | 5,213,882 | 4,943,852 | 5,182,283 | 5,486,785 | 5,567,219 | 5,498,276 | 5,435,077 | 5,538,493 | 5,460,931 | 5,090,357 | 5,323,043 | 5,258,131 | 5,263,294 | 5,000,000 |
| C000004434 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | SUSIX | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 17,363,526 | 17,088,312 | 16,688,000 | 16,525,373 | 15,899,886 | 15,186,831 | 15,837,337 | 15,349,457 | 14,411,227 | 14,085,973 | 13,486,585 | 12,342,194 | 12,502,163 | 13,129,732 | 13,265,090 | 12,871,321 | 12,108,394 | 11,923,815 | 11,690,014 | 11,357,772 | 11,702,320 | 10,951,698 | 11,581,494 | 10,952,065 | 10,217,731 | 11,266,780 | 11,749,342 | 10,731,765 | 11,654,927 | 11,633,947 | 12,724,957 | 12,431,223 | 12,903,295 | 13,438,564 | 12,901,330 | 13,115,283 | 12,309,395 | 12,879,935 | 12,608,929 | 12,309,395 | 12,059,784 | 11,959,940 | 11,303,819 | 10,840,256 | 10,490,800 | 10,654,830 | 10,280,994 | 9,320,981 | 9,511,622 | 9,899,712 | 9,184,809 | 8,640,120 | 8,497,140 | 8,068,198 | 7,121,801 | 8,054,580 | 8,694,589 | 8,660,546 | 8,393,906 | 8,093,210 | 7,875,685 | 7,773,320 | 7,920,470 | 7,837,298 | 7,274,292 | 7,754,127 | 7,421,442 | 7,267,894 | 7,088,756 | 6,544,944 | 7,185,058 | 7,004,060 | 7,541,568 | 7,459,296 | 7,272,814 | 6,982,121 | 6,916,304 | 6,757,245 | 6,762,730 | 6,916,304 | 7,135,695 | 6,751,760 | 6,716,046 | 6,582,071 | 6,461,061 | 6,357,339 | 6,348,695 | 6,201,755 | 6,145,571 | 6,119,641 | 6,033,205 | 5,998,631 | 5,769,576 | 5,605,349 | 5,510,818 | 5,340,881 | 5,462,265 | 5,429,896 | 5,385,388 | 5,170,944 | 5,235,682 | 5,102,160 | 5,057,652 | 4,758,239 | 4,770,378 | 5,102,160 | 5,238,420 | 5,251,757 | 4,821,613 | 5,035,018 | 5,398,473 | 5,255,092 | 5,335,119 | 5,271,764 | 5,231,751 | 5,298,440 | 4,985,001 | 5,201,741 | 5,225,173 | 5,092,379 | 5,000,000 |
| C000004433 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | SUSSX | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 16,953,025 | 16,690,918 | 16,303,001 | 16,156,222 | 15,548,136 | 14,845,691 | 15,485,230 | 15,013,439 | 14,101,310 | 13,786,782 | 13,195,267 | 12,086,160 | 12,231,277 | 12,853,206 | 12,987,957 | 12,604,434 | 11,868,485 | 11,692,271 | 11,464,231 | 11,132,535 | 11,474,596 | 10,749,012 | 11,365,395 | 10,750,071 | 10,026,160 | 11,057,733 | 11,537,323 | 10,532,898 | 11,446,834 | 11,428,737 | 12,505,554 | 12,225,038 | 12,677,482 | 13,202,710 | 12,673,843 | 12,892,025 | 12,102,718 | 12,667,426 | 12,404,323 | 12,109,135 | 11,865,284 | 11,769,027 | 11,127,313 | 10,671,696 | 10,331,588 | 10,498,434 | 10,132,888 | 9,183,700 | 9,374,770 | 9,756,911 | 9,054,265 | 8,524,199 | 8,382,437 | 7,957,152 | 7,026,455 | 7,944,825 | 8,579,671 | 8,548,853 | 8,286,353 | 7,994,375 | 7,778,311 | 7,679,038 | 7,825,027 | 7,743,273 | 7,194,353 | 7,667,359 | 7,340,343 | 7,188,514 | 7,007,487 | 6,476,086 | 7,107,164 | 6,929,485 | 7,462,522 | 7,386,374 | 7,203,619 | 6,914,255 | 6,853,337 | 6,701,040 | 6,706,117 | 6,858,413 | 7,076,705 | 6,695,964 | 6,665,758 | 6,531,549 | 6,413,606 | 6,311,932 | 6,303,798 | 6,157,388 | 6,104,517 | 6,076,048 | 5,994,709 | 5,962,173 | 5,734,423 | 5,571,744 | 5,481,691 | 5,313,142 | 5,431,893 | 5,401,247 | 5,359,110 | 5,148,423 | 5,209,714 | 5,079,471 | 5,037,333 | 4,742,372 | 4,753,864 | 5,087,132 | 5,220,486 | 5,236,451 | 4,808,595 | 5,022,523 | 5,386,520 | 5,242,837 | 5,325,854 | 5,261,995 | 5,223,679 | 5,293,924 | 4,981,015 | 5,198,136 | 5,222,841 | 5,091,922 | 5,000,000 |
| SPDR ETFs Index: S&P500 Index | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | S&P 500 Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 17,549,010 | 17,182,051 | 16,775,142 | 16,573,404 | 15,999,315 | 15,243,472 | 15,892,598 | 15,397,200 | 14,616,731 | 14,375,167 | 13,750,474 | 12,599,793 | 12,870,413 | 13,514,769 | 13,733,426 | 13,305,972 | 12,481,269 | 12,427,252 | 12,236,263 | 11,802,928 | 12,098,109 | 11,382,878 | 12,078,791 | 11,439,506 | 10,582,715 | 11,656,238 | 12,151,812 | 11,125,950 | 12,126,954 | 12,104,747 | 13,261,143 | 12,786,390 | 13,181,050 | 13,900,352 | 13,304,113 | 13,396,940 | 12,519,781 | 13,130,477 | 12,743,017 | 12,447,332 | 12,163,380 | 12,079,016 | 11,467,035 | 10,985,900 | 10,691,094 | 10,800,130 | 10,400,259 | 9,374,129 | 9,630,234 | 10,010,603 | 9,339,290 | 8,840,801 | 8,668,410 | 8,274,320 | 7,334,131 | 8,367,642 | 9,118,249 | 9,121,825 | 8,854,576 | 8,544,423 | 8,363,277 | 8,209,670 | 8,341,807 | 8,223,617 | 7,682,204 | 8,203,522 | 7,884,290 | 7,734,005 | 7,493,405 | 6,937,466 | 7,626,026 | 7,473,724 | 8,022,031 | 7,976,628 | 7,724,910 | 7,447,752 | 7,402,192 | 7,228,124 | 7,200,496 | 7,388,255 | 7,670,986 | 7,255,575 | 7,175,790 | 6,962,259 | 6,803,497 | 6,665,990 | 6,645,646 | 6,511,747 | 6,471,356 | 6,381,550 | 6,316,678 | 6,309,318 | 6,068,368 | 5,955,415 | 5,839,981 | 5,631,422 | 5,736,055 | 5,734,970 | 5,726,930 | 5,523,293 | 5,509,018 | 5,411,832 | 5,390,933 | 5,048,455 | 5,055,275 | 5,319,238 | 5,404,477 | 5,388,453 | 4,969,274 | 5,095,351 | 5,422,512 | 5,311,235 | 5,416,080 | 5,347,317 | 5,296,507 | 5,381,614 | 5,089,134 | 5,246,634 | 5,259,884 | 5,122,126 | 5,000,000 |
| SPDR ETFs Index: S&P500 Index | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | S&P 500 Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 17,549,010 | 17,182,051 | 16,775,142 | 16,573,404 | 15,999,315 | 15,243,472 | 15,892,598 | 15,397,200 | 14,616,731 | 14,375,167 | 13,750,474 | 12,599,793 | 12,870,413 | 13,514,769 | 13,733,426 | 13,305,972 | 12,481,269 | 12,427,252 | 12,236,263 | 11,802,928 | 12,098,109 | 11,382,878 | 12,078,791 | 11,439,506 | 10,582,715 | 11,656,238 | 12,151,812 | 11,125,950 | 12,126,954 | 12,104,747 | 13,261,143 | 12,786,390 | 13,181,050 | 13,900,352 | 13,304,113 | 13,396,940 | 12,519,781 | 13,130,477 | 12,743,017 | 12,447,332 | 12,163,380 | 12,079,016 | 11,467,035 | 10,985,900 | 10,691,094 | 10,800,130 | 10,400,259 | 9,374,129 | 9,630,234 | 10,010,603 | 9,339,290 | 8,840,801 | 8,668,410 | 8,274,320 | 7,334,131 | 8,367,642 | 9,118,249 | 9,121,825 | 8,854,576 | 8,544,423 | 8,363,277 | 8,209,670 | 8,341,807 | 8,223,617 | 7,682,204 | 8,203,522 | 7,884,290 | 7,734,005 | 7,493,405 | 6,937,466 | 7,626,026 | 7,473,724 | 8,022,031 | 7,976,628 | 7,724,910 | 7,447,752 | 7,402,192 | 7,228,124 | 7,200,496 | 7,388,255 | 7,670,986 | 7,255,575 | 7,175,790 | 6,962,259 | 6,803,497 | 6,665,990 | 6,645,646 | 6,511,747 | 6,471,356 | 6,381,550 | 6,316,678 | 6,309,318 | 6,068,368 | 5,955,415 | 5,839,981 | 5,631,422 | 5,736,055 | 5,734,970 | 5,726,930 | 5,523,293 | 5,509,018 | 5,411,832 | 5,390,933 | 5,048,455 | 5,055,275 | 5,319,238 | 5,404,477 | 5,388,453 | 4,969,274 | 5,095,351 | 5,422,512 | 5,311,235 | 5,416,080 | 5,347,317 | 5,296,507 | 5,381,614 | 5,089,134 | 5,246,634 | 5,259,884 | 5,122,126 | 5,000,000 |
| SPDR ETFs Index: S&P500 Index | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | S&P 500 Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 17,549,010 | 17,182,051 | 16,775,142 | 16,573,404 | 15,999,315 | 15,243,472 | 15,892,598 | 15,397,200 | 14,616,731 | 14,375,167 | 13,750,474 | 12,599,793 | 12,870,413 | 13,514,769 | 13,733,426 | 13,305,972 | 12,481,269 | 12,427,252 | 12,236,263 | 11,802,928 | 12,098,109 | 11,382,878 | 12,078,791 | 11,439,506 | 10,582,715 | 11,656,238 | 12,151,812 | 11,125,950 | 12,126,954 | 12,104,747 | 13,261,143 | 12,786,390 | 13,181,050 | 13,900,352 | 13,304,113 | 13,396,940 | 12,519,781 | 13,130,477 | 12,743,017 | 12,447,332 | 12,163,380 | 12,079,016 | 11,467,035 | 10,985,900 | 10,691,094 | 10,800,130 | 10,400,259 | 9,374,129 | 9,630,234 | 10,010,603 | 9,339,290 | 8,840,801 | 8,668,410 | 8,274,320 | 7,334,131 | 8,367,642 | 9,118,249 | 9,121,825 | 8,854,576 | 8,544,423 | 8,363,277 | 8,209,670 | 8,341,807 | 8,223,617 | 7,682,204 | 8,203,522 | 7,884,290 | 7,734,005 | 7,493,405 | 6,937,466 | 7,626,026 | 7,473,724 | 8,022,031 | 7,976,628 | 7,724,910 | 7,447,752 | 7,402,192 | 7,228,124 | 7,200,496 | 7,388,255 | 7,670,986 | 7,255,575 | 7,175,790 | 6,962,259 | 6,803,497 | 6,665,990 | 6,645,646 | 6,511,747 | 6,471,356 | 6,381,550 | 6,316,678 | 6,309,318 | 6,068,368 | 5,955,415 | 5,839,981 | 5,631,422 | 5,736,055 | 5,734,970 | 5,726,930 | 5,523,293 | 5,509,018 | 5,411,832 | 5,390,933 | 5,048,455 | 5,055,275 | 5,319,238 | 5,404,477 | 5,388,453 | 4,969,274 | 5,095,351 | 5,422,512 | 5,311,235 | 5,416,080 | 5,347,317 | 5,296,507 | 5,381,614 | 5,089,134 | 5,246,634 | 5,259,884 | 5,122,126 | 5,000,000 |
| SPDR ETFs Index: S&P500 Index | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | S&P 500 Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 17,549,010 | 17,182,051 | 16,775,142 | 16,573,404 | 15,999,315 | 15,243,472 | 15,892,598 | 15,397,200 | 14,616,731 | 14,375,167 | 13,750,474 | 12,599,793 | 12,870,413 | 13,514,769 | 13,733,426 | 13,305,972 | 12,481,269 | 12,427,252 | 12,236,263 | 11,802,928 | 12,098,109 | 11,382,878 | 12,078,791 | 11,439,506 | 10,582,715 | 11,656,238 | 12,151,812 | 11,125,950 | 12,126,954 | 12,104,747 | 13,261,143 | 12,786,390 | 13,181,050 | 13,900,352 | 13,304,113 | 13,396,940 | 12,519,781 | 13,130,477 | 12,743,017 | 12,447,332 | 12,163,380 | 12,079,016 | 11,467,035 | 10,985,900 | 10,691,094 | 10,800,130 | 10,400,259 | 9,374,129 | 9,630,234 | 10,010,603 | 9,339,290 | 8,840,801 | 8,668,410 | 8,274,320 | 7,334,131 | 8,367,642 | 9,118,249 | 9,121,825 | 8,854,576 | 8,544,423 | 8,363,277 | 8,209,670 | 8,341,807 | 8,223,617 | 7,682,204 | 8,203,522 | 7,884,290 | 7,734,005 | 7,493,405 | 6,937,466 | 7,626,026 | 7,473,724 | 8,022,031 | 7,976,628 | 7,724,910 | 7,447,752 | 7,402,192 | 7,228,124 | 7,200,496 | 7,388,255 | 7,670,986 | 7,255,575 | 7,175,790 | 6,962,259 | 6,803,497 | 6,665,990 | 6,645,646 | 6,511,747 | 6,471,356 | 6,381,550 | 6,316,678 | 6,309,318 | 6,068,368 | 5,955,415 | 5,839,981 | 5,631,422 | 5,736,055 | 5,734,970 | 5,726,930 | 5,523,293 | 5,509,018 | 5,411,832 | 5,390,933 | 5,048,455 | 5,055,275 | 5,319,238 | 5,404,477 | 5,388,453 | 4,969,274 | 5,095,351 | 5,422,512 | 5,311,235 | 5,416,080 | 5,347,317 | 5,296,507 | 5,381,614 | 5,089,134 | 5,246,634 | 5,259,884 | 5,122,126 | 5,000,000 |
| SPDR ETFs Index: Russell 2000 Index | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 2000 Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 11,605,070 | 11,524,525 | 11,699,287 | 10,620,276 | 10,719,434 | 10,207,359 | 10,980,172 | 10,600,679 | 10,033,375 | 10,439,400 | 9,302,756 | 8,530,651 | 9,155,012 | 9,727,703 | 10,239,992 | 9,649,868 | 8,924,307 | 9,007,513 | 9,172,419 | 9,632,665 | 9,798,165 | 8,927,989 | 9,547,654 | 9,329,732 | 8,404,490 | 9,295,311 | 9,489,492 | 8,592,420 | 9,362,413 | 9,348,286 | 10,376,715 | 10,249,153 | 10,140,899 | 11,221,206 | 10,976,020 | 11,453,275 | 10,985,940 | 11,319,700 | 11,072,037 | 11,486,811 | 11,268,489 | 11,245,306 | 11,014,023 | 10,904,502 | 10,264,750 | 9,772,953 | 8,994,891 | 7,594,953 | 7,439,148 | 7,696,227 | 7,285,725 | 7,089,499 | 6,847,459 | 6,429,088 | 5,652,669 | 7,221,688 | 7,885,507 | 8,146,787 | 7,918,462 | 7,605,388 | 7,410,229 | 7,259,191 | 7,636,223 | 7,592,511 | 7,091,316 | 7,689,336 | 7,436,707 | 7,595,679 | 7,220,311 | 6,490,176 | 7,365,039 | 7,249,804 | 8,133,204 | 8,333,647 | 7,989,231 | 7,852,376 | 7,796,509 | 7,350,339 | 7,287,338 | 7,194,289 | 7,484,085 | 7,293,475 | 7,323,032 | 7,117,898 | 7,057,736 | 6,643,144 | 6,728,748 | 6,679,125 | 6,455,954 | 6,590,021 | 6,518,536 | 6,510,017 | 6,386,760 | 6,361,667 | 6,188,274 | 5,567,437 | 5,845,324 | 5,780,934 | 5,680,479 | 5,360,426 | 5,363,808 | 5,245,650 | 5,164,594 | 4,782,865 | 4,783,079 | 5,244,228 | 5,521,459 | 5,347,511 | 5,062,300 | 5,323,487 | 5,680,451 | 5,747,245 | 5,704,527 | 5,577,199 | 5,723,155 | 5,625,158 | 5,309,927 | 5,486,403 | 5,334,373 | 5,329,596 | 5,000,000 |
| SPDR ETFs Index: Russell 2000 Index | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 2000 Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 11,605,070 | $ 11,524,525 | $ 11,699,287 | $ 10,620,276 | $ 10,719,434 | $ 10,207,359 | $ 10,980,172 | $ 10,600,679 | $ 10,033,375 | $ 10,439,400 | $ 9,302,756 | $ 8,530,651 | $ 9,155,012 | $ 9,727,703 | $ 10,239,992 | $ 9,649,868 | $ 8,924,307 | $ 9,007,513 | $ 9,172,419 | $ 9,632,665 | $ 9,798,165 | $ 8,927,989 | $ 9,547,654 | $ 9,329,732 | $ 8,404,490 | $ 9,295,311 | $ 9,489,492 | $ 8,592,420 | $ 9,362,413 | $ 9,348,286 | $ 10,376,715 | $ 10,249,153 | $ 10,140,899 | $ 11,221,206 | $ 10,976,020 | $ 11,453,275 | $ 10,985,940 | $ 11,319,700 | $ 11,072,037 | $ 11,486,811 | $ 11,268,489 | $ 11,245,306 | $ 11,014,023 | $ 10,904,502 | $ 10,264,750 | $ 9,772,953 | $ 8,994,891 | $ 7,594,953 | $ 7,439,148 | $ 7,696,227 | $ 7,285,725 | $ 7,089,499 | $ 6,847,459 | $ 6,429,088 | $ 5,652,669 | $ 7,221,688 | $ 7,885,507 | $ 8,146,787 | $ 7,918,462 | $ 7,605,388 | $ 7,410,229 | $ 7,259,191 | $ 7,636,223 | $ 7,592,511 | $ 7,091,316 | $ 7,689,336 | $ 7,436,707 | $ 7,595,679 | $ 7,220,311 | $ 6,490,176 | $ 7,365,039 | $ 7,249,804 | $ 8,133,204 | $ 8,333,647 | $ 7,989,231 | $ 7,852,376 | $ 7,796,509 | $ 7,350,339 | $ 7,287,338 | $ 7,194,289 | $ 7,484,085 | $ 7,293,475 | $ 7,323,032 | $ 7,117,898 | $ 7,057,736 | $ 6,643,144 | $ 6,728,748 | $ 6,679,125 | $ 6,455,954 | $ 6,590,021 | $ 6,518,536 | $ 6,510,017 | $ 6,386,760 | $ 6,361,667 | $ 6,188,274 | $ 5,567,437 | $ 5,845,324 | $ 5,780,934 | $ 5,680,479 | $ 5,360,426 | $ 5,363,808 | $ 5,245,650 | $ 5,164,594 | $ 4,782,865 | $ 4,783,079 | $ 5,244,228 | $ 5,521,459 | $ 5,347,511 | $ 5,062,300 | $ 5,323,487 | $ 5,680,451 | $ 5,747,245 | $ 5,704,527 | $ 5,577,199 | $ 5,723,155 | $ 5,625,158 | $ 5,309,927 | $ 5,486,403 | $ 5,334,373 | $ 5,329,596 | $ 5,000,000 |
| Shareholder Report, Average Annual Return (Details) | 12 Months Ended | 60 Months Ended | 120 Months Ended |
| Sep. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2024 | |
| C000004429 | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | SIVIX | ||
| C000004430 | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | SSQSX | ||
| C000004434 | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | SUSIX | ||
| C000004433 | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | SUSSX | ||
| Without Sales Load [Member] | C000004429 | |||
| Average Annual Return [Line Items] | |||
| Average Annual Return, Percent | 22.81% | 10.08% | 9.39% |
| Without Sales Load [Member] | C000004430 | |||
| Average Annual Return [Line Items] | |||
| Average Annual Return, Percent | 22.53% | 9.80% | 9.12% |
| Without Sales Load [Member] | C000004434 | |||
| Average Annual Return [Line Items] | |||
| Average Annual Return, Percent | 38.88% | 17.13% | 13.26% |
| Without Sales Load [Member] | C000004433 | |||
| Average Annual Return [Line Items] | |||
| Average Annual Return, Percent | 38.60% | 16.86% | 12.99% |
| SPDR ETFs Index: S&P500 Index | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | S&P 500 Index | ||
| Average Annual Return, Percent | 36.35% | 15.98% | 13.38% |
| SPDR ETFs Index: S&P500 Index | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | S&P 500 Index | ||
| Average Annual Return, Percent | 36.35% | 15.98% | 13.38% |
| SPDR ETFs Index: S&P500 Index | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | S&P 500 Index | ||
| Average Annual Return, Percent | 36.35% | 15.98% | 13.38% |
| SPDR ETFs Index: S&P500 Index | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | S&P 500 Index | ||
| Average Annual Return, Percent | 36.35% | 15.98% | 13.38% |
| SPDR ETFs Index: Russell 2000 Index | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Russell 2000 Index | ||
| Average Annual Return, Percent | 26.76% | 9.39% | 8.79% |
| SPDR ETFs Index: Russell 2000 Index | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Russell 2000 Index | ||
| Average Annual Return, Percent | 26.76% | 9.39% | 8.79% |
| Shareholder Report, Holdings (Details) | Sep. 30, 2024 |
| C000004429 | MGP Ingredients, Inc.FR_55303J106 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| C000004429 | Enerpac Tool Group Corp.FR_292765104 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.60% |
| C000004429 | Belden, Inc.FR_077454106 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| C000004429 | Brink's Co.FR_109696104 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| C000004429 | Darling Ingredients, Inc.FR_237266101 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000004429 | Louisiana-Pacific Corp.FR_546347105 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| C000004429 | Cullen/Frost Bankers, Inc.FR_229899109 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000004429 | Dycom Industries, Inc.FR_267475101 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000004429 | U.S. Physical Therapy, Inc.FR_90337L108 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000004429 | Repligen Corp.FR_759916109 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000004429 | IndustryRegional Banks | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.10% |
| C000004429 | IndustryIndustrial Machinery & Supplies & Components | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.20% |
| C000004429 | IndustryApplication Software | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000004429 | IndustryHealthcare Equipment | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000004429 | IndustrySpecialty Chemicals | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| C000004429 | IndustryLife Sciences Tools & Services | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000004429 | IndustryBiotechnology | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000004429 | IndustryPackaged Foods & Meats | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| C000004429 | IndustryProperty & Casualty Insurance | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000004429 | IndustryBuilding Products | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000004430 | MGP Ingredients, Inc.FR_55303J106 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| C000004430 | Enerpac Tool Group Corp.FR_292765104 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.60% |
| C000004430 | Belden, Inc.FR_077454106 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| C000004430 | Brink's Co.FR_109696104 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| C000004430 | Darling Ingredients, Inc.FR_237266101 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| C000004430 | Louisiana-Pacific Corp.FR_546347105 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| C000004430 | Cullen/Frost Bankers, Inc.FR_229899109 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000004430 | Dycom Industries, Inc.FR_267475101 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000004430 | U.S. Physical Therapy, Inc.FR_90337L108 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000004430 | Repligen Corp.FR_759916109 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| C000004430 | IndustryRegional Banks | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.10% |
| C000004430 | IndustryIndustrial Machinery & Supplies & Components | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.20% |
| C000004430 | IndustryApplication Software | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000004430 | IndustryHealthcare Equipment | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| C000004430 | IndustrySpecialty Chemicals | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| C000004430 | IndustryLife Sciences Tools & Services | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| C000004430 | IndustryBiotechnology | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000004430 | IndustryPackaged Foods & Meats | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| C000004430 | IndustryProperty & Casualty Insurance | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| C000004430 | IndustryBuilding Products | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000004434 | NVIDIA Corp.FR_67066G104 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.10% |
| C000004434 | Microsoft Corp.FR_594918104 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7% |
| C000004434 | Apple, Inc.FR_037833100 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.10% |
| C000004434 | Amazon.com, Inc.FR_023135106 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000004434 | Alphabet, Inc.FR_02079K305 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| C000004434 | Meta Platforms, Inc.FR_30303M102 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000004434 | Broadcom, Inc.FR_11135F101 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| C000004434 | JPMorgan Chase & Co.FR_46625H100 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000004434 | Home Depot, Inc.FR_437076102 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000004434 | UnitedHealth Group, Inc.FR_91324P102 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.70% |
| C000004434 | IndustryApplication Software | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000004434 | IndustryHealthcare Equipment | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000004434 | IndustrySemiconductors | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.40% |
| C000004434 | IndustrySystems Software | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.30% |
| C000004434 | IndustryInteractive Media & Services | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.80% |
| C000004434 | IndustryTechnology Hardware, Storage & Peripherals | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.10% |
| C000004434 | IndustryPharmaceuticals | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5% |
| C000004434 | IndustryBroadline Retail | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000004434 | IndustryTransaction & Payment Processing Services | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000004434 | IndustryDiversified Banks | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000004433 | NVIDIA Corp.FR_67066G104 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.10% |
| C000004433 | Microsoft Corp.FR_594918104 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7% |
| C000004433 | Apple, Inc.FR_037833100 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.10% |
| C000004433 | Amazon.com, Inc.FR_023135106 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000004433 | Alphabet, Inc.FR_02079K305 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| C000004433 | Meta Platforms, Inc.FR_30303M102 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| C000004433 | Broadcom, Inc.FR_11135F101 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| C000004433 | JPMorgan Chase & Co.FR_46625H100 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| C000004433 | Home Depot, Inc.FR_437076102 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| C000004433 | UnitedHealth Group, Inc.FR_91324P102 | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.70% |
| C000004433 | IndustryApplication Software | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000004433 | IndustryHealthcare Equipment | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| C000004433 | IndustrySemiconductors | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.40% |
| C000004433 | IndustrySystems Software | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.30% |
| C000004433 | IndustryInteractive Media & Services | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.80% |
| C000004433 | IndustryTechnology Hardware, Storage & Peripherals | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.10% |
| C000004433 | IndustryPharmaceuticals | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5% |
| C000004433 | IndustryBroadline Retail | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.20% |
| C000004433 | IndustryTransaction & Payment Processing Services | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000004433 | IndustryDiversified Banks | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
