Annual report pursuant to Section 13 and 15(d)

Concentrations of Risk - Additional Information (Detail)

v3.22.0.1
Concentrations of Risk - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Mar. 31, 2021
Dec. 31, 2021
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
May 31, 2021
Jul. 31, 2017
Mortgage Loans held for sale       $ 168,700 $ 85,800    
Debt instrument, face amount   $ 350,000 $ 350,000 $ 350,009      
Percentgae of entity revenue 21.00% 22.00%   23.00% 24.00%    
Mortgage Loans Customer | Credit Concentration Risk | Residential Mortgage | Mortgage Loans Benchmark              
Concentration Risk, Percentage     100.00% 100.00%      
Mortgage Loans Customer | Credit Concentration Risk | Non Agency Reverse Mortgage | Mortgage Loans Benchmark              
Concentration Risk, Percentage     100.00% 100.00%      
Mortgage Loans Customer | Credit Concentration Risk | Reverse Mortgage | Mortgage Loans Benchmark              
Concentration Risk, Percentage     100.00% 100.00%      
Mortgage Loans Customer | Credit Concentration Risk | Non Performing HECM Buyouts | Mortgage Loans Benchmark              
Concentration Risk, Percentage     100.00% 100.00%      
Mortgage Loans Customer | Credit Concentration Risk | Commercial Mortgage | Mortgage Loans Benchmark              
Concentration Risk, Percentage     100.00% 100.00%      
Mortgage Loans Customer | Credit Concentration Risk | Minimum [Member] | Residential Mortgage | Mortgage Loans Benchmark              
Concentration Risk, Percentage     5.00%        
Mortgage Loans Customer | Credit Concentration Risk | Minimum [Member] | Non Agency Reverse Mortgage | Mortgage Loans Benchmark              
Concentration Risk, Percentage     5.00%        
Mortgage Loans Customer | Credit Concentration Risk | Minimum [Member] | Reverse Mortgage | Mortgage Loans Benchmark              
Concentration Risk, Percentage     5.00%        
Mortgage Loans Customer | Credit Concentration Risk | Minimum [Member] | Non Performing HECM Buyouts | Mortgage Loans Benchmark              
Concentration Risk, Percentage     5.00%        
Mortgage Loans Customer | Credit Concentration Risk | Minimum [Member] | Commercial Mortgage | Mortgage Loans Benchmark              
Concentration Risk, Percentage     5.00%        
Nonaffiliated Blackstone Portfolio Companies              
Mortgage Loans held for sale $ 84,600 $ 424,800          
Gain (loss) on sale of mortgage loans 4,000 17,300   $ 7,900 $ 3,000    
Nonaffiliated Blackstone Portfolio Companies | Mezzanine Financing Agreement              
Long-term Debt   21,500 $ 21,500 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 $ 1,724,300 $ 7,439,800   $ 5,855,200 $ 6,471,200    
Percentage of Nonperforming repurchased loans         8.70%    
Percentage of non-agency reverse mortgage loans   18.60%   34.10% 23.10%    
Percentage of commercial loans 14.10% 6.10%   7.60% 5.70%    
Percentage of Thirdparty financial institutions       16.10%      
Percentage of residential mortgage loans 52.80% 75.30%   38.20% 49.50%    
Percentage of non-assignable buy outs loans 33.10%            
Percentage of reverse mortgage loans       4.00% 13.00%    
FNMA, FHLMC and GNMA              
Mortgage Loans held for sale $ 7,696,600 $ 20,516,100   $ 27,229,100 $ 12,448,600