XML 60 R50.htm IDEA: XBRL DOCUMENT v3.23.3
Equity Securities - (Summary of Investments in Equity Securities, by Classification) (Detail) - USD ($)
$ in Millions
Sep. 30, 2023
Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]    
Marketable equity securities $ 407.3 $ 279.5
Non-marketable equity securities 226.7 395.8
Equity Method Investments 74.7 78.9
Equity Securities $ 708.7 $ 754.2