Consolidated Statements of Financial Condition (Parenthetical) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Securities available-for-sale, encumbered	$ 29,902,000	$ 9,915,000
Securities held-to-maturity, net estimated fair value	397,763,000	474,215,000
Securities held-to-maturity, net encumbered	$ 371,270,000	$ 421,427,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, liquidation preference	$ 1,000	$ 1,000
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	55,000,000	55,000,000
Common stock, shares issued	33,566,772	33,566,772
Common stock, shares outstanding	17,286,557	16,901,653
Treasury stock, shares	16,280,215	16,665,119