CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands |
Mar. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Statement of Financial Position [Abstract] | ||
| Investment securities available-for-sale, amortized cost (in dollars) | $ 787,062 | $ 781,232 |
| 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 | 28,205,674 |
| Cost of common stock in treasury, shares | 2,356,417 | 2,178,090 |