XML 95 R74.htm IDEA: XBRL DOCUMENT v3.20.4
Securities Owned/Sold but Not Yet Purchased - Schedule of Securities Owned/Sold But Not Yet Purchased (Detail) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Security Owned and Sold Not yet Purchased, at Fair Value [Line Items]    
Securities Owned Total $ 34,895 $ 17,319
Securities Sold, but not yet Purchased Total 0 582
Trading Securities [Member]    
Security Owned and Sold Not yet Purchased, at Fair Value [Line Items]    
Securities Owned Total 34,895 17,319
Securities Sold, but not yet Purchased Total $ 0 $ 582