CONDENSED CONSOLIDATED STATEMENTS OF CONDITION (Parenthetical) - USD ($) $ in Thousands |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Statement of Financial Position [Abstract] | ||
| Available-for-sale securities, at amortized cost | $ 1,408,360 | $ 1,409,996 |
| Held-to-maturity securities, at fair value | $ 137,843 | $ 140,315 |
| 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) | 15,321,245 | 15,301,524 |
| Treasury stock, shares (in shares) | 116,587 | 120,805 |