Balance Sheet Parenthetical Parentheticals (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Investment securities available for sale at amortized cost	$ 814,469	$ 833,375
Preferred stock par value per share	$ 1.00	$ 1.00
Preferred stock shares authorized	2,000,000	2,000,000
Series B Preferred stock shares issued	401	401
Series B Preferred stock shares outstanding	401	401
Series B Preferred stock liquidation value per share	$ 100,000	$ 100,000
Common stock par value per share	$ 1.00	$ 1.00
Common stock shares authorized	170,000,000	170,000,000
Common stock shares issued	78,151,609	78,023,317