Quarterly report pursuant to Section 13 or 15(d)

Warehouse Lines of Credit - Summary of Warehouse Lines of Credit (Details)

v3.21.2
Warehouse Lines of Credit - Summary of Warehouse Lines of Credit (Details) - Line of Credit - USD ($)
 9 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Warehouse Agreement Borrowings    
Warehouse Lines of Credit [Line Items]    
Warehouse lines of credit $ 1,909,574,000 $ 2,145,584,000
Prepaid commitment fees (1,579,000) (2,141,000)
Total 1,907,995,000 2,143,443,000
Warehouse Agreement Borrowings | $800 Million Master Repurchase Facility Agreement Due January 2022    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity 800,000,000  
Warehouse lines of credit $ 262,389,000 442,593,000
Line of credit, floor interest rate 0.75%  
Warehouse Agreement Borrowings | $250 Million Master Repurchase Facility Agreement Due September 2021    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 250,000,000  
Warehouse lines of credit 175,901,000 148,011,000
Minimum deposit required for line of credit 1,250,000  
Warehouse Agreement Borrowings | $500 Million Master Repurchase Facility Agreement Due February 2022    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity 500,000,000  
Warehouse lines of credit 289,547,000 541,074,000
Minimum deposit required for line of credit 2,500,000  
Warehouse Agreement Borrowings | $200 Million Master Repurchase Facility Agreement Due June 2021    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity 200,000,000  
Warehouse lines of credit 99,873,000 187,214,000
Minimum deposit required for line of credit $ 750,000  
Warehouse Agreement Borrowings | $200 Million Master Repurchase Facility Agreement Due June 2021 | LIBOR    
Warehouse Lines of Credit [Line Items]    
Line of credit, floor interest rate 1.525%  
Warehouse Agreement Borrowings | $300 Million Master Repurchase Facility Agreement Due September 2021    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 300,000,000  
Warehouse lines of credit $ 134,855,000 232,272,000
Warehouse Agreement Borrowings | $300 Million Master Repurchase Facility Agreement Due September 2021 | LIBOR    
Warehouse Lines of Credit [Line Items]    
Line of credit, floor interest rate 0.40%  
Warehouse Agreement Borrowings | $500 Million Master Repurchase Facility Agreement Due July 2022    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 500,000,000  
Warehouse lines of credit $ 299,674,000 464,355,000
Warehouse Agreement Borrowings | $500 Million Master Repurchase Facility Agreement Due July 2022 | LIBOR    
Warehouse Lines of Credit [Line Items]    
Line of credit, floor interest rate 0.50%  
Warehouse Agreement Borrowings | $200 Million Master Repurchase Facility Agreement Due April 2022    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 200,000,000  
Warehouse lines of credit $ 117,980,000 104,880,000
Warehouse Agreement Borrowings | $200 Million Master Repurchase Facility Agreement Due April 2022 | LIBOR    
Warehouse Lines of Credit [Line Items]    
Line of credit, floor interest rate 1.00%  
Warehouse Agreement Borrowings | $250 Million Master Repurchase Facility Agreement Due 30 Days From Written Notice    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 250,000,000  
Warehouse lines of credit $ 170,786,000 0
Maturity, period from written notice 30 days  
Warehouse Agreement Borrowings | $75 Million Master Repurchase Facility Agreement Due March 2024    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 75,000,000  
Warehouse lines of credit $ 38,108,000 25,185,000
Stated interest rate 3.375%  
Maximum term of buyout transactions on facility 4 years  
Warehouse Agreement Borrowings | $200 Million Master Repurchase Facility Agreement Due January 2022    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 200,000,000  
Warehouse lines of credit $ 148,459,000 0
Warehouse Agreement Borrowings | $200 Million Master Repurchase Facility Agreement Due January 2022 | LIBOR    
Warehouse Lines of Credit [Line Items]    
Line of credit, floor interest rate 0.75%  
Debt instrument variable rate 1.75%  
Warehouse Agreement Borrowings | $200 Million Master Repurchase Facility Agreement    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 200,000,000  
Warehouse lines of credit $ 103,739,000 0
Maturity, period from written notice 30 days  
Warehouse Agreement Borrowings | $200 Million Master Repurchase Facility Agreement | LIBOR    
Warehouse Lines of Credit [Line Items]    
Debt instrument variable rate 1.75%  
Warehouse Agreement Borrowings | $30 Million Master Repurchase Facility Agreement    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 30,000,000  
Warehouse lines of credit $ 13,712,000 0
Warehouse Agreement Borrowings | $30 Million Master Repurchase Facility Agreement | LIBOR | Minimum    
Warehouse Lines of Credit [Line Items]    
Debt instrument variable rate 2.00%  
Warehouse Agreement Borrowings | $30 Million Master Repurchase Facility Agreement | LIBOR | Maximum    
Warehouse Lines of Credit [Line Items]    
Debt instrument variable rate 3.50%  
Warehouse Agreement Borrowings | $75 Million Master Repurchase Facility Agreement Due March 2022    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 75,000,000  
Warehouse lines of credit $ 54,551,000 $ 0
Warehouse Agreement Borrowings | $75 Million Master Repurchase Facility Agreement Due March 2022 | LIBOR    
Warehouse Lines of Credit [Line Items]    
Line of credit, floor interest rate 0.75%  
Debt instrument variable rate 1.75%  
Construction Loan Advances | $200 Million Master Repurchase Facility Agreement Due January 2022    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 10,000,000  
Construction Loan Advances | $200 Million Master Repurchase Facility Agreement Due January 2022 | LIBOR    
Warehouse Lines of Credit [Line Items]    
Debt instrument variable rate 3.00%  
Construction Loan Advances | $30 Million Master Repurchase Facility Agreement    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 10,000,000  
Construction Loan Advances | $30 Million Master Repurchase Facility Agreement | LIBOR    
Warehouse Lines of Credit [Line Items]    
Debt instrument variable rate 2.50%  
Construction Loan Advances | $75 Million Master Repurchase Facility Agreement Due March 2022    
Warehouse Lines of Credit [Line Items]    
Borrowing capacity $ 20,000,000  
Construction Loan Advances | $75 Million Master Repurchase Facility Agreement Due March 2022 | LIBOR    
Warehouse Lines of Credit [Line Items]    
Line of credit, floor interest rate 1.00%  
Debt instrument variable rate 2.65%