Consolidated Statements of Financial Position (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Financial Position [Abstract]
Held-to-maturity, fair value	$ 183,769	$ 159,188
Preferred stock, no par value
Preferred stock, shares authorized	200,000	200,000
Preferred stock, shares issued
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	45,000,000	30,000,000
Common stock, shares issued	27,456,907	27,440,006
Common stock, shares outstanding	27,456,907	27,440,006