XML 72 R61.htm IDEA: XBRL DOCUMENT v3.20.2
Goodwill - Schedule of Changes in Carrying Amount of Goodwill (Detail)
$ in Millions
9 Months Ended
Sep. 30, 2020
USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]  
Balance at December 31, 2019 $ 421.3
Measurement period adjustment (Note 2) 0.7
Balance at September 30, 2020 $ 422.0