XML 52 R40.htm IDEA: XBRL DOCUMENT v3.21.2
Investments - Equity Investments Included in Marketable Securities (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]    
Equity investments included in marketable securities $ 44,748 $ 0