Consolidated Balance Sheet (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Consolidated Balance Sheet [Abstract]
Pledged securities that can be sold or repledged	$ 0	$ 1,826,011
Investment securities, available for sale, amortized cost	5,510,097	6,312,423
Investment securities, held to maturity, fair value	1,131,836	1,012,562
Other, fair value	$ 334,781	$ 366,886
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	381,500	381,500
Preferred stock, shares outstanding	50,000	50,000
Preferred stock, liquidation preference per share	$ 1,000	$ 1,000
Liquidation preference, per share	$ 10,000	$ 10,000
Common stock, par value	$ 0.50	$ 0.50
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	126,587,931	125,683,398
Common stock issuable, shares	57,231	68,220