XML 62 R49.htm IDEA: XBRL DOCUMENT v3.20.2
Goodwill - Summary of Changes in the Carrying Amount of Goodwill by Segment (Parenthetical) (Detail) - USD ($)
$ in Billions
Sep. 30, 2020
Dec. 31, 2019
Goodwill [Line Items]    
Accumulated goodwill impairment $ 25.6 $ 21.0