Other Borrowings - Summary of Balances of Other Borrowings (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Other collateralized borrowings, fixed rate, as of December 31, 2016 of 0.05%, payable on January 2, 2017	$ 17,493,000	$ 12,328,000
Total other borrowings	17,493,000	12,328,000
0.05% Fixed Rate Collateralized Borrowings [Member]
Debt Instrument [Line Items]
Other collateralized borrowings, fixed rate, as of December 31, 2016 of 0.05%, payable on January 2, 2017	$ 17,493,000	$ 12,328,000