XML 113 R97.htm IDEA: XBRL DOCUMENT v3.10.0.1
Fair Values of Assets and Liabilities - Valuation Assumption Ranges for Derivative Commitments (Detail) - Derivative Mortgage Loans Commitments [Member]
Jun. 30, 2018
Minimum [Member]  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Expected loan close rate 8.00%
Inherent MSR value (basis points per loan) 21.00%
Maximum [Member]  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Expected loan close rate 100.00%
Inherent MSR value (basis points per loan) 185.00%
Average [Member]  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Expected loan close rate 79.00%
Inherent MSR value (basis points per loan) 109.00%