Loans and Loans Held for Sale - Summary of Nonperforming Assets of Defaulted TDRs (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015 Contract	Mar. 31, 2014 Contract
Financing Receivable, Modifications [Line Items]
Number of Defaults	2	1
Recorded Investment	$ 188	$ 72
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults	1	1
Recorded Investment	183	72
Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults	1	0
Recorded Investment	$ 5	$ 0