Related Party Transactions - Summary of Deposits and Withdrawals Made by Related Parties (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Deposits and Withdrawals $120000 or More
Related Party Transaction [Line Items]
Deposits	$ 0	$ 500,000	$ 750,000	$ 1,650,000
Withdrawals	$ 99,000	$ 22,000	553,000	$ 132,000
Minimum
Related Party Transaction [Line Items]
Related party transaction threshold			$ 120,000