CONDENSED CONSOLIDATED STATEMENTS OF CONDITION (Parenthetical) - USD ($) $ in Thousands |
Jun. 30, 2017 |
Dec. 31, 2016 |
|---|---|---|
| Statement of Financial Position [Abstract] | ||
| Available-for-sale securities, at amortized cost | $ 1,433,013 | $ 1,442,724 |
| Held-to-maturity securities, at fair value | $ 141,654 | $ 142,832 |
| Common Stock, par value (in dollars per share) | $ 0.10 | $ 0.10 |
| Common Stock, authorized (in shares) | 25,000,000 | 25,000,000 |
| Common Stock, issued (in shares) | 15,225,363 | 15,171,816 |
| Treasury stock, shares (in shares) | 117,302 | 117,997 |