Consolidated Balance Sheets (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Statement of Financial Position [Abstract]
Available for sale securities, amortized cost	$ 628,584	$ 617,128
Held to maturity securities, fair value	$ 47,124	$ 16,705
Preferred stock, shares authorized	50,000	50,000
Preferred stock, shares issued	0	0
Common stock, shares authorized	24,000,000	24,000,000
Common stock, shares issued	11,155,648	11,122,247
Treasury stock, shares	607,688	615,123