Quarterly report pursuant to Section 13 or 15(d)

Business, Basis of Presentation, and Accounting Policies - Additional Information (Details)

v3.20.2
Business, Basis of Presentation, and Accounting Policies - Additional Information (Details)
 1 Months Ended 9 Months Ended
Oct. 22, 2020
$ / shares
shares
Oct. 01, 2020
USD ($)
$ / shares
shares
Oct. 21, 2020
Sep. 30, 2020
USD ($)
Subsidiary
$ / shares
shares
Sep. 30, 2019
USD ($)
Dec. 31, 2019
USD ($)
$ / shares
shares
Business Basis Of Presentation And Accounting Policies [Line Items]            
Number of wholly owned subsidiaries | Subsidiary       4    
Dividend distributed | $       $ 10,000,000 $ 12,500,000  
Common stock, par value | $ / shares       $ 100   $ 100
Common stock, shares, issued | shares       928   928
Total account balance for trust for investors and escrow balances for mortgagors | $       $ 1,700,000,000   $ 1,000,000,000.0
Credit losses due to nonperformance of counterparties | $       $ 0 $ 0  
IPO and Reorganization | Class A Common Stock            
Business Basis Of Presentation And Accounting Policies [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant | shares       1,440,334    
Common stock, shares, issued | shares       6,500,000    
Percentage of combined voting power       1.50%    
IPO and Reorganization | Common Class B | McCarthy Capital Mortgage Investors, LLC            
Business Basis Of Presentation And Accounting Policies [Line Items]            
Common stock, par value | $ / shares       $ 0.01    
Common stock, shares, issued | shares       40,333,019    
Common stock, voting rights       10 votes per share    
Subsequent Event            
Business Basis Of Presentation And Accounting Policies [Line Items]            
Dividend declared | $   $ 27,600,000        
Dividend distributed | $   $ 27,600,000        
Subsequent Event | IPO and Reorganization            
Business Basis Of Presentation And Accounting Policies [Line Items]            
Percentage of ownership after transaction     100.00%      
Subsequent Event | IPO and Reorganization | Class A Common Stock            
Business Basis Of Presentation And Accounting Policies [Line Items]            
Stock issued during period, shares, new issues | shares 6,500,000          
Common stock, par value | $ / shares $ 0.01          
Sale of stock, price per share | $ / shares $ 15.00          
Subsequent Event | IPO | Class A Common Stock | Restricted Stock Units | 2020 Omnibus Incentive Plan            
Business Basis Of Presentation And Accounting Policies [Line Items]            
Equity-based awards shares issued | shares   1,440,334        
Shares issued, price per share | $ / shares   $ 15        
Equity-based awards, total value | $   $ 21,605,010,000        
Equity-based awards, weighted average life   2 years 9 months 18 days        
Subsequent Event | IPO | Class A Common Stock | Restricted Stock Units | 2020 Omnibus Incentive Plan | Minimum            
Business Basis Of Presentation And Accounting Policies [Line Items]            
Equity-based awards, vesting period   2 years        
Subsequent Event | IPO | Class A Common Stock | Restricted Stock Units | 2020 Omnibus Incentive Plan | Maximum            
Business Basis Of Presentation And Accounting Policies [Line Items]            
Equity-based awards, vesting period   4 years