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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount of undisbursed portion of the loan receivable balance (loans in process). Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans held for sale. Excludes loans and leases covered under loss sharing agreements.

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Loans receivable (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Loans receivable
Total loans receivable, gross	$ 6,191,472	$ 6,129,584
Deferred loan costs	7,741	6,095
Allowance for loan losses	(67,298)	(67,518)	(76,234)	(71,348)
Total loans, net	5,997,566us-gaap_LoansReceivableNet	5,922,373us-gaap_LoansReceivableNet
Residential mortgage loans
Loans receivable
Undisbursed loan proceeds	(7,987)	(10,879)
Commercial real estate loans
Loans receivable
Undisbursed loan proceeds	(113,586)	(73,760)
Commercial loans
Loans receivable
Undisbursed loan proceeds	(12,776)	(61,149)
Personal Banking
Loans receivable
Total loans receivable, gross	3,839,811	3,835,115
Allowance for loan losses	(14,955)	(16,249)	(19,705)	(20,607)
Personal Banking \| Residential mortgage loans
Loans receivable
Total loans receivable, gross	2,544,116	2,526,240
Allowance for loan losses	(5,077)	(5,581)	(7,467)	(7,875)
Personal Banking \| Home equity loans
Loans receivable
Total loans receivable, gross	1,055,739	1,066,131
Allowance for loan losses	(4,043)	(4,550)	(6,958)	(7,245)
Personal Banking \| Other consumer loans
Loans receivable
Total loans receivable, gross	239,956	242,744
Allowance for loan losses	(5,835)	(6,118)	(5,280)	(5,487)
Business Banking
Loans receivable
Total loans receivable, gross	2,351,661	2,294,469
Allowance for loan losses	(48,365)	(46,904)	(52,378)	(46,079)
Business Banking \| Commercial real estate loans
Loans receivable
Total loans receivable, gross	1,970,160	1,874,944
Allowance for loan losses	(33,252)	(33,389)	(36,209)	(35,199)
Business Banking \| Commercial loans
Loans receivable
Total loans receivable, gross	381,501	419,525
Allowance for loan losses	$ (15,113)	$ (13,515)	$ (16,169)	$ (10,880)