v2.4.0.6
Assets and Liabilities Measured at Fair Value on Non-Recurring Basis (Detail) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Assets    
Impaired loans $ 1,149,104 $ 1,112,788
Fair Value, Measurements, Nonrecurring [Member]
   
Assets    
Impaired loans 18,493 21,680
Fair Value, Measurements, Nonrecurring [Member] | Construction [Member]
   
Assets    
Impaired loans 4,051 3,787
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Commercial [Member]
   
Assets    
Impaired loans 771 383
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Nonresidential Real Estate [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Commercial Mortgage Loans, Owner Occupied [Member] | Nonresidential Real Estate [Member]
   
Assets    
Impaired loans 5,892 8,320
Fair Value, Measurements, Nonrecurring [Member] | Commercial Mortgage Loans, Non Owner Occupied [Member] | Nonresidential Real Estate [Member]
   
Assets    
Impaired loans 3,732 5,858
Fair Value, Measurements, Nonrecurring [Member] | Home Equity Line of Credit [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 147 0
Fair Value, Measurements, Nonrecurring [Member] | Multi Family [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 1,081 0
Fair Value, Measurements, Nonrecurring [Member] | Residential Real Estate Other Financing Receivable [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 2,819 3,332
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Construction [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Impaired Loans [Member] | Commercial [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial Mortgage Loans, Owner Occupied [Member] | Nonresidential Real Estate [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial Mortgage Loans, Non Owner Occupied [Member] | Nonresidential Real Estate [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Home Equity Line of Credit [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Multi Family [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Residential Real Estate Other Financing Receivable [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
   
Assets    
Impaired loans 0 2,421
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Construction [Member]
   
Assets    
Impaired loans 0 214
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Impaired Loans [Member] | Commercial [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage Loans, Owner Occupied [Member] | Nonresidential Real Estate [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage Loans, Non Owner Occupied [Member] | Nonresidential Real Estate [Member]
   
Assets    
Impaired loans 0 375
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Home Equity Line of Credit [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Multi Family [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 0 0
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Residential Real Estate Other Financing Receivable [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 0 1,832
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
   
Assets    
Impaired loans 18,493 19,259
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Construction [Member]
   
Assets    
Impaired loans 4,051 3,573
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Impaired Loans [Member] | Commercial [Member]
   
Assets    
Impaired loans 771 383
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commercial Mortgage Loans, Owner Occupied [Member] | Nonresidential Real Estate [Member]
   
Assets    
Impaired loans 5,892 8,320
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commercial Mortgage Loans, Non Owner Occupied [Member] | Nonresidential Real Estate [Member]
   
Assets    
Impaired loans 3,732 5,483
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Home Equity Line of Credit [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 147 0
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multi Family [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans 1,081 0
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Residential Real Estate Other Financing Receivable [Member] | Residential Real Estate [Member]
   
Assets    
Impaired loans $ 2,819 $ 1,500