Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Statement of Financial Position [Abstract] | ||
| Cash and due from banks, interest-bearing amounts | $ 68,961 | $ 41,639 |
| Common stock, par value (in dollars per share) | $ 2.50 | $ 2.50 |
| Common stock, shares authorized (in shares) | 50,000,000 | 50,000,000 |
| Common stock, shares issued (in shares) | 36,130,480 | 36,130,480 |
| Common stock, shares outstanding (in shares) | 34,913,023 | 34,810,374 |
| Treasury stock, shares (in shares) | 1,217,457 | 1,320,106 |