CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
CONSOLIDATED BALANCE SHEETS (Parenthetical)
Securities held-to-maturity, fair value	$ 2,791,215	$ 4,411,856
Preferred stock, share authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	95,000	95,000
Preferred stock, shares outstanding (in shares)	95,000	95,000
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, shares authorized (in shares)	90,000,000	90,000,000
Common stock, shares issued (in shares)	34,136,163	33,870,380
Common stock, shares outstanding (in shares)	34,136,163	33,870,380