Quarterly report pursuant to Section 13 or 15(d)

Loans - Additional Information (Detail)

v2.4.0.8
Loans - Additional Information (Detail) (USD $)
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2014
Property
Sep. 30, 2013
Sep. 30, 2014
Property
Sep. 30, 2013
Dec. 31, 2013
Property
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Accrued interest receivable $ 9,880,000   $ 9,880,000   $ 7,055,000
Loans receivable 2,628,091,000   2,628,091,000   2,177,498,000
Loans receivable reclassified as loans held for sale 0 0 0 8,010,000  
Sale of loans held for sale 14,268,000 11,906,000 26,986,000 71,626,000  
Allowance for off-balance sheet items 1,500,000 1,300,000 1,500,000 1,300,000  
Loans on non-accrual status 24,003,000   24,003,000   25,877,000
Percentage decrease in loans on non-accrual status, excluding loans held for sale         7.20%
Delinquent loans (defined as 30 days or more past due) 19,200,000   19,200,000   16,300,000
Percentage increase in delinquent loans excluding loans held for sale         18.20%
Number of real estate properties 40   40   3
Other real estate owned, net 24,781,000   24,781,000   756,000
Net valuation adjustment     0   56,000
TDR loans receivable 26,400,000   26,400,000   30,000,000
Principal and interest due     6 months    
Reserves relating to loans included in allowance for loan losses 3,700,000   3,700,000   2,800,000
Net carrying value 4,576,000 3,107,000 8,370,000 5,189,000  
Number of loans restructured 3   14    
Serviced loans sold to unaffiliated parties 341,600,000 330,400,000 341,600,000 330,400,000  
Recoveries of previously charged-off and reimbursed Commercial SLA loans which needs to be reimbursed     80.00%    
FDIC loss sharing asset 7,696,000   7,696,000    
Single-family loans covered 3,700,000   3,700,000    
Minimum [Member]
          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Due period for considering loans as impaired     90 days    
Central Bancorp, Inc [Member]
          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Other real estate owned, net 22,300,000   22,300,000    
Securities Pledged as Collateral [Member]
          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Loans receivable 872,200,000   872,200,000   568,700,000
Commercial Properties [Member]
          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Other real estate owned, net 20,200,000   20,200,000    
Residential Properties [Member]
          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Other real estate owned, net 4,600,000   4,600,000    
Loans and Finance Receivables [Member]
          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Accrued interest receivable $ 5,800,000   $ 5,800,000   $ 5,400,000