Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Consolidated Balance Sheets [Abstract]
Investment securities held to maturity; fair value	$ 94,129	$ 74,274
Preferred stock, Series A, no par value
Preferred stock, Series A, liquidation value	$ 1,000	$ 1,000
Preferred stock, Series A, shares authorized	1,000,000	1,000,000
Preferred stock, Series A, shares issued	0	19,000
Common stock, no par value
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	27,274,714	27,275,480
Treasury stock, shares	281,812	439,340