XML 67 R56.htm IDEA: XBRL DOCUMENT v3.21.2
Equity Securities (Narrative) (Detail) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Schedule Of Investments [Line Items]          
Realized and unrealized net gains (losses) on equity securities $ (16,100) $ 26,000 $ 27,200 $ 2,600  
Net unrealized gains (losses) on equity securities (16,700) 26,100 25,500 2,400  
Investments in non marketable equity securities 379,548   379,548   $ 217,104
Offerpad Inc          
Schedule Of Investments [Line Items]          
Net unrealized gains (losses) on equity securities 195,300   195,300    
Investments in non marketable equity securities 280,300   280,300   280,300
Non Marketable Equity Securities          
Schedule Of Investments [Line Items]          
Investments in non marketable equity securities 379,548   379,548   217,104
Cost 198,155   198,155   $ 200,858
Net unrealized gains on equity securities 79,400 $ 9,300 165,100 $ 9,300  
Non Marketable Equity Securities | Side Inc          
Schedule Of Investments [Line Items]          
Investments in non marketable equity securities 73,800   73,800    
Cost 10,100   10,100    
Non Marketable Equity Securities | Orchard Technologies Inc          
Schedule Of Investments [Line Items]          
Investments in non marketable equity securities 106,300   106,300    
Cost $ 41,000   $ 41,000