Equity And Earnings Per Share (Tables)	12 Months Ended
Dec. 31, 2021
Equity And Earnings Per Share [Abstract]
IBG LLC Ownership of Member Interests	IBG, Inc. Holdings Total Ownership %23.5% 76.5% 100.0% Membership interests 98,230,127 319,880,492 418,110,619
Earnings Per Share Basic And Diluted	Basic earnings per share is calculated utilizing net income available for common stockholders divided by the weighted average number of shares of Class A and Class B common stock outstanding for that period. Year-Ended December 31, 2021 2020 2019 (in millions, except share or per share amounts)Basic earnings per share Net income available for common stockholders $ 308 $ 195 $ 161Weighted average shares of common stock outstanding Class A 94,167,472 79,939,189 76,121,470Class B 100 100 100 94,167,572 79,939,289 76,121,570Basic earnings per share $ 3.27 $ 2.44 $ 2.11 Diluted earnings per share are calculated utilizing the Company’s basic net income available for common stockholders divided by diluted weighted average shares outstanding with no adjustments to net income available to common stockholders for potentially dilutive common shares. Year-Ended December 31, 2021 2020 2019 (in millions, except share or per share amounts)Diluted earnings per share Net income available for common stockholders $ 308 $ 195 $ 161Weighted average shares of common stock outstanding Class A Issued and outstanding 94,167,472 79,939,189 76,121,470Potentially dilutive common shares Issuable pursuant to employee stock incentive plans 842,308 699,619 704,293Class B 100 100 100 95,009,880 80,638,908 76,825,863Diluted earnings per share $ 3.24 $ 2.42 $ 2.10

Equity And Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2021

Equity And Earnings Per Share [Abstract]

IBG, Inc. Holdings Total Ownership %23.5% 76.5% 100.0% Membership interests 98,230,127 319,880,492 418,110,619

Basic earnings per share is calculated utilizing net income available for common stockholders divided by the weighted average number of shares of Class A and Class B common stock outstanding for that period. Year-Ended December 31, 2021 2020 2019 (in millions, except share or per share amounts)Basic earnings per share Net income available for common stockholders $ 308 $ 195 $ 161Weighted average shares of common stock outstanding Class A 94,167,472 79,939,189 76,121,470Class B 100 100 100 94,167,572 79,939,289 76,121,570Basic earnings per share $ 3.27 $ 2.44 $ 2.11 Diluted earnings per share are calculated utilizing the Company’s basic net income available for common stockholders divided by diluted weighted average shares outstanding with no adjustments to net income available to common stockholders for potentially dilutive common shares. Year-Ended December 31, 2021 2020 2019 (in millions, except share or per share amounts)Diluted earnings per share Net income available for common stockholders $ 308 $ 195 $ 161Weighted average shares of common stock outstanding Class A Issued and outstanding 94,167,472 79,939,189 76,121,470Potentially dilutive common shares Issuable pursuant to employee stock incentive plans 842,308 699,619 704,293Class B 100 100 100 95,009,880 80,638,908 76,825,863Diluted earnings per share $ 3.24 $ 2.42 $ 2.10