Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
ASSETS
Fair value of held-to-maturity investment securities	$ 46,296	$ 45,639
Accumulated amortization and fair value adjustments on other intangibles	$ 12,542	$ 11,646
SHAREHOLDERS' EQUITY
Common stock, par value	$ 5	$ 5
Common stock, shares authorized	48,000,000	48,000,000
Common stock, shares issued	18,266,404	18,266,404
Common stock, shares outstanding	16,759,893	16,702,376
Treasury stock, shares	1,506,511	1,564,028