Reserve for Repurchased Loans and Loss Sharing Obligations - Additional Information (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2016 USD ($) SecurityLoan	Dec. 31, 2015 SecurityLoan	Sep. 30, 2015 USD ($)
Receivables [Abstract]
Reserve for repurchased loans and loss sharing obligations | $	$ 986,000		$ 1,032,000
Outstanding number of loan repurchase requests | SecurityLoan	0	0