CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Investment securities available-for-sale, amortized cost (in dollars)	$ 826,007	$ 822,163
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)
Common stock, Authorized shares	40,000,000	40,000,000
Common stock, issued shares	25,641,887	25,641,887
Cost of common stock in treasury, shares	1,306,006	1,319,377