Annual report pursuant to Section 13 and 15(d)

Loans and Leases - Additional Information (Detail)

v3.6.0.2
Loans and Leases - Additional Information (Detail)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
USD ($)
Property
SecurityLoan
Dec. 31, 2015
USD ($)
Property
Dec. 31, 2014
USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Accrued interest receivable $ 10,987 $ 9,501  
Loans receivable 3,812,340 3,140,381  
Reclassification from loans receivable to loans held for sale 0 360 $ 0
Sale of loans held for sale $ 84,901 $ 89,471  
Number of real estate properties | Property 12 14  
Net carrying value of other real estate property $ 7,484 $ 8,511  
TDR loans receivable $ 18,000 17,200 26,300
Principal and interest due 6 months    
Reserves relating to loans included in allowance for loan losses $ 3,400 1,000 $ 2,900
Number of loans restructured | SecurityLoan 7    
Serviced loans sold to unaffiliated parties $ 484,700 474,000  
Central Bancorp, Inc [Member]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Net carrying value of other real estate property 5,700 7,400  
Securities Pledged as Collateral [Member]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Loans receivable 1,000,000 557,700  
Residential Real Estate [Member]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Net carrying value of other real estate property 4,100    
Loans and Finance Receivables [Member]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Accrued interest receivable $ 8,200 $ 7,900