Label	Element	Value
Institutional | U.S. Core Equity 2 Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	32.50%
Institutional | Dimensional VA Global Bond Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	12.40%
Institutional | DFA Selectively Hedged Global Fixed Income Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	12.40%
Institutional | U.S. Core Equity 1 Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	11.60%
Institutional | International Core Equity 2 Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	11.10%
Institutional | Emerging Markets Core Equity 2 Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	5.10%
Institutional | DFA Two-Year Global Fixed Income Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	5.00%
Institutional | Dimensional VA Short-Term Fixed Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	5.00%
Institutional | Dimensional VA U.S. Large Value Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	2.30%
Institutional | Dimensional VA International Value Portfolio [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	1.30%