| Label | Element | Value |
|---|---|---|
| Institutional | U.S. Core Equity 2 Portfolio [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 52.90% |
| Institutional | International Core Equity 2 Portfolio [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 18.40% |
| Institutional | U.S. Core Equity 1 Portfolio [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 17.70% |
| Institutional | Emerging Markets Core Equity 2 Portfolio [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 9.20% |
| Institutional | DFA Real Estate Securities Portfolio [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 1.30% |
| Institutional | DFA International Real Estate Securities Portfolio [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 0.50% |