Commitments and Credit Risk - Additional Information (Detail) |
6 Months Ended |
---|---|
Jun. 30, 2018 | |
Minimum [Member] | |
Commitments And Contingencies [Line Items] | |
Fixed interest rate loan commitments | 3.75% |
Fixed interest rate loan commitments maturity period | 1 month |
Maximum [Member] | |
Commitments And Contingencies [Line Items] | |
Fixed interest rate loan commitments | 8.50% |
Fixed interest rate loan commitments maturity period | 110 months |