Consolidated Balance Sheets (unaudited) (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Consolidated Balance Sheets (unaudited) (Parenthetical) [Abstract]
Securities held-to-maturity, fair value	$ 2,270,068	$ 1,956,720
Loans, allowance for loan losses	9,973,887	13,227,791
Foreclosed assets, valuation allowance	$ 1,978,500	$ 2,123,930
Common stock, par value (in dollars per share)	$ 5	$ 5
Common stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, shares issued (in shares)	4,955,259	4,936,989
Common stock, shares outstanding (in shares)	4,955,259	4,936,989