Shareholder Report, Average Annual Return (Details) DFBZ_DFA Short-Term Government Portfolio_Institutional_TSR Annual {Institutional}		12 Months Ended	60 Months Ended	120 Months Ended
		Oct. 31, 2025	Oct. 31, 2025	Oct. 31, 2025
Institutional
Average Annual Return [Line Items]
Line Graph and Table Measure Name		DFA Short-Term Government Portfolio – Institutional
Average Annual Return, Percent		4.37%	1.55%	1.27%
Bloomberg U.S. Aggregate Bond Index [Member]
Average Annual Return [Line Items]
Line Graph and Table Measure Name		Bloomberg U.S. Aggregate Bond Index
Average Annual Return, Percent		6.16%	(0.24%)	1.90%
ICE BofA 1-5 Year US Treasury & Agency Index [Member]
Average Annual Return [Line Items]
Line Graph and Table Measure Name		ICE BofA 1-5 Year US Treasury & Agency Index
Average Annual Return, Percent	[1]	5.28%	1.23%	1.72%

[1] 1 ICE BofA index data copyright 2025 ICE Data Indices, LLC. Prior to July 1, 2022, index returns reflect no deduction for transaction costs. Effective July 1, 2022, index returns include transaction costs (as determined and calculated by the index provider), which may be higher or lower than the actual transaction costs incurred by the Portfolio.