Loans - Summary of Loans (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]        
Total loans, Amount $ 2,292,256 $ 1,806,937    
Allowance for loan losses (25,335) (20,504) (13,053) (10,155)
Net deferred loan origination fees (1,521) (94)    
Loans, net 2,265,400 1,786,339    
One-to Four-Family [Member]
       
Financing Receivable, Allowance for Credit Losses [Line Items]        
Total loans, Amount 454,148 443,228    
Allowance for loan losses (1,991) (2,507) (1,861) (1,130)
Multi-Family Residential Real Estate [Member]
       
Financing Receivable, Allowance for Credit Losses [Line Items]        
Total loans, Amount 288,172 178,948    
Allowance for loan losses (2,419) (1,431) (1,361) (1,038)
Home Equity Lines of Credit [Member]
       
Financing Receivable, Allowance for Credit Losses [Line Items]        
Total loans, Amount 54,499 60,907    
Allowance for loan losses (155) (226) (245) (227)
Commercial Real Estate [Member]
       
Financing Receivable, Allowance for Credit Losses [Line Items]        
Total loans, Amount 1,032,408 795,642    
Allowance for loan losses (12,831) (10,405) (6,980) (5,238)
Construction [Member]
       
Financing Receivable, Allowance for Credit Losses [Line Items]        
Total loans, Amount 208,799 173,255    
Allowance for loan losses (4,374) (3,656) (1,430) (2,042)
Total Real Estate Loans [Member]
       
Financing Receivable, Allowance for Credit Losses [Line Items]        
Total loans, Amount 2,038,026 1,651,980    
Commercial Business Loans [Member]
       
Financing Receivable, Allowance for Credit Losses [Line Items]        
Total loans, Amount 247,005 147,814    
Allowance for loan losses (3,433) (2,174) (1,061) (448)
Consumer [Member]
       
Financing Receivable, Allowance for Credit Losses [Line Items]        
Total loans, Amount 7,225 7,143    
Allowance for loan losses $ (132) $ (105) $ (115) $ (32)