v3.26.1
Equity And Earnings Per Share (IBG LLC Ownership of Member Interests) (Details)
Jun. 30, 2026
shares
Ownership Percentage 100.00%
Membership Interests 1,701,408,529
IBG Inc [Member]  
Ownership Percentage 26.50%
Membership Interests 450,671,113
Holdings [Member]  
Ownership Percentage 73.50%
Membership Interests 1,250,737,416