Loans Receivable, Financial Instruments Whose Contract Amounts Represent Credit Risk (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Standby Letters of Credit [Member]
Financial instruments whose contract amount represents credit risk [Abstract]
Off-balance sheet credit risk	$ 7,357,000	$ 14,719,000
Current liability for guarantees	314,000	0
Letters of credit expiry period	12 months
Home Equity Lines of Credit [Member]
Financial instruments whose contract amount represents credit risk [Abstract]
Off-balance sheet credit risk	8,571,000	12,345,000
Loan expiry period	10 years
Unadvanced Construction Commitments [Member]
Financial instruments whose contract amount represents credit risk [Abstract]
Off-balance sheet credit risk	36,162,000	34,023,000
Mortgage Loan Commitments [Member]
Financial instruments whose contract amount represents credit risk [Abstract]
Off-balance sheet credit risk	2,120,000	4,193,000
Fixed rate loan commitments	2,120,000	4,193,000
Fixed interest rate, minimum (in hundredths)	3.75%	3.625%
Fixed interest rate, maximum (in hundredths)	4.50%	5.25%
Floating rate loan commitments	0	0
Lines of Credit [Member]
Financial instruments whose contract amount represents credit risk [Abstract]
Off-balance sheet credit risk	23,844,000	30,965,000
Loans Sold with Limited Repurchase Provisions [Member]
Financial instruments whose contract amount represents credit risk [Abstract]
Off-balance sheet credit risk	38,247,000	28,134,000
Loans receivable held-for-sale, amount	$ 90,560,000	$ 124,178,000
Period of delinquency under repurchase agreement, minimum	90 days	90 days
Period of delinquency under repurchase agreement, maximum	120 days	120 days