Quarterly report pursuant to Section 13 or 15(d)

Concentrations of Risk - Additional Information (Detail)

v3.21.2
Concentrations of Risk - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2021
Mar. 31, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
May 31, 2021
May 30, 2021
Dec. 31, 2020
Jul. 31, 2017
Gain (loss) on sale of mortgage loans $ 197,129 $ 284,948 $ 282,424   $ 291,671        
Debt instrument, face amount $ 350,000     $ 350,000       $ 350,009  
Percentgae of entity revenue 23.00% 21.00% 25.00%   23.00%        
Minimum [Member] | Residential Mortgage                  
Concentration Risk, Percentage       5.00%          
Minimum [Member] | Non Agency Reverse Mortgage                  
Concentration Risk, Percentage       5.00%          
Minimum [Member] | Reverse Mortgage                  
Concentration Risk, Percentage       5.00%          
Minimum [Member] | Non Performing HECM Buyouts                  
Concentration Risk, Percentage       5.00%          
Minimum [Member] | Commercial Mortgage                  
Concentration Risk, Percentage       5.00%          
Nonaffiliated Blackstone Portfolio Companies                  
Mortgage Loans held for sale $ 33,400 $ 84,600     $ 98,700        
Gain (loss) on sale of mortgage loans 900 4,000 $ 0   4,700        
Nonaffiliated Blackstone Portfolio Companies | Mezzanine Financing Agreement                  
Long-term Debt 20,900     $ 20,900       $ 21,500  
Debt instrument, face amount                 $ 45,000
Nonaffiliated Blackstone Portfolio Companies | Mezzanie Financing Amendment Agreement [Member]                  
Debt instrument, face amount           $ 25,000 $ 45,000    
Private Investors                  
Mortgage Loans held for sale 1,691,900 $ 1,724,300 $ 1,883,300   $ 3,384,100        
Percentage of Nonperforming repurchased loans   33.20% 0.10%   11.00%        
Percentage of Other Nonperforming repurchased loans   66.80%              
Percentage of non-agency reverse mortgage loans     46.80%   31.90%        
Percentage of commercial loans     23.50%   13.10%        
Percentage of Thirdparty financial institutions     3.30%   6.90%        
Percentage of Other thirdparty financial institutions     26.30%   37.10%        
FNMA, FHLMC and GNMA                  
Mortgage Loans held for sale $ 6,421,200 $ 7,696,600 $ 7,274,400   $ 10,850,600