Commitments and Contingencies (Details) (USD $)					9 Months Ended
	Sep. 30, 2014 Commitments to extend credit	Dec. 31, 2013 Commitments to extend credit	Sep. 30, 2014 Standby letters of credit	Dec. 31, 2013 Standby letters of credit	Sep. 30, 2014 Standby letters of credit Minimum	Sep. 30, 2014 Standby letters of credit Maximum	Sep. 30, 2014 Unadvanced Commitment on Impaired Loan	Dec. 31, 2013 Unadvanced Commitment on Impaired Loan	Sep. 30, 2014 Fixed Rate Loan Commitment Commitments to extend credit	Dec. 31, 2013 Fixed Rate Loan Commitment Commitments to extend credit
Schedule of Commitments [Line Items]
Commitment to lend							$ 0	$ 100,000
Estimated losses attributable to unadvanced commitments on impaired loans							200,000	200,000
Off-balance sheet financial instruments, contractual amounts	$ 879,258,000	$ 804,420,000	$ 45,791,000	$ 44,376,000					$ 66,400,000	$ 50,300,000
Remaing term of letters of credit					1 month	3 years 4 months 24 days