v3.26.1
Form N-1A Cover
Oct. 31, 2025
Prospectus [Line Items]  
Document Type 497
Amendment Flag false
Registrant Name DIMENSIONAL INVESTMENT GROUP INC
Entity Central Index Key 0000861929
Entity Investment Company Type N-1A
Document Period End Date Oct. 31, 2025
Prospectus Date Feb. 28, 2026
DFA INVESTMENT DIMENSIONS GROUP INC [Member]  
Prospectus [Line Items]  
Registrant Name DFA INVESTMENT DIMENSIONS GROUP INC
Entity Central Index Key 0000355437