CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Investment securities available-for-sale, amortized cost (in dollars)	$ 769,053	$ 776,057
Preferred stock; no par value (in dollars per share)	$ 0	$ 0
Preferred stock, Authorized shares	10,000,000	10,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock; no par value (in dollars per share)	$ 0	$ 0
Common stock, Authorized shares	40,000,000	40,000,000
Common stock, issued shares	28,205,674	28,206,076	[1]
Cost of common stock in treasury, shares	2,123,527	1,957,386	[1]

[1] *December 31, 2014 share data gives retrospective recognition to a 10% stock dividend declared on July 22, 2015 and issued on August 14, 2015.