CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
ASSETS
Securities—trading, Amortized Cost Basis	$ 42,716	$ 47,480
Securities—available-for-sale, Amortized Cost Basis	416,731	411,424
Securities—held-to-maturity, Fair Value	$ 138,255	$ 137,608
STOCKHOLDERS’ EQUITY
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	500,000	500,000
Preferred Stock, Shares Outstanding	0	0
Voting Common Stock [Member]
STOCKHOLDERS’ EQUITY
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	50,000,000	50,000,000
Common Stock, Shares Issued	20,970,681	19,571,548
Common Stock, Shares Outstanding	20,970,681	19,571,548
Nonvoting Common Stock [Member]
STOCKHOLDERS’ EQUITY
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	5,000,000	5,000,000
Common Stock, Shares Issued	0	0
Common Stock, Shares Outstanding	0	0