XML 73 R59.htm IDEA: XBRL DOCUMENT v3.20.4
Fixed Assets, Net - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Property, Plant and Equipment [Abstract]      
Depreciation expense $ 4.1 $ 4.9 $ 5.7