Consolidated Statements of Financial Condition (Parenthetical) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Securities held-to-maturity, net estimated fair value	$ 695,564,000	$ 598,119,000
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, liquidation preference	$ 1,000,000	$ 1,000,000
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in usd per share)	$ 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	32,465,413	32,136,892
Treasury stock, shares	1,101,359	1,429,880