Loans Receivable, Net - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]
Loans with non-accrual of interest	$ 18,307,000	$ 45,360,000	$ 43,374,000
Financing receivables 90 days past due and still accruing	0
Impaired loans on non-accrual commercial real estate, multi-family, land, construction and commercial loans	250,000
Impaired loan portfolio total	36,979,000	39,903,000
Allocation in allowance for loan losses	2,161,000	3,647,000
Average balance of impaired loans	41,023,000	38,587,000	36,574,000
Interest income on non-accrual loans	1,630,000	2,513,000	2,370,000
Troubled debt restructuring loans	23,493,000	31,119,000
Troubled debt restructuring loans with accrual interest	21,462,000	21,456,000
Carrying amount of non-performing residential and consumer mortgage loans	23,100,000
Non-accrual loan total troubled debt restructurings	2,031,000	9,663,000	18,160,000
Specific reserves to loans accruing troubled debt restructurings	419,000	1,816,000	2,418,000
Loans classified as troubled debt restructurings	$ 21,462,000	$ 21,456,000	$ 17,733,000