Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Schedule of Fair Value Liabilities Measured On Non-Recurring Basis Valuation Techniques (Detail)

v3.20.2
Fair Value Measurements - Schedule of Fair Value Liabilities Measured On Non-Recurring Basis Valuation Techniques (Detail) - Mortgage Rights [Member] - Fair Value, Inputs, Level 3 [Member] - Fair Value, Nonrecurring [Member]
$ in Thousands
Jun. 30, 2020
USD ($)
Dec. 31, 2019
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Amount $ 2,316 $ 2,204
Constant prepayment rates [Member] | Minimum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.000 0.000
Constant prepayment rates [Member] | Maximum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.200 0.200
Constant prepayment rates [Member] | Weighted Average [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.100 0.100
Constant default rate [Member] | Minimum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.004 0.020
Constant default rate [Member] | Maximum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.050 0.020
Constant default rate [Member] | Weighted Average [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.015 0.020
Loss severity [Member] | Minimum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.242 0.400
Loss severity [Member] | Maximum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.500 0.400
Loss severity [Member] | Weighted Average [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.301 0.400
Discount rate [Member] | Minimum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.100 0.095
Discount rate [Member] | Maximum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.100 0.097
Discount rate [Member] | Weighted Average [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Range 0.100 0.097