Consolidated Balance Sheet (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Pledged securities that can be sold or repledged	$ 1,707,437	$ 1,801,842
Investment securities, available for sale, amortized cost	4,555,109	4,643,070
Investment securities, held to maturity, fair value	3,277,386	976,883
Other, fair value	$ 298,479	$ 302,648
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, shares authorized	1,000,000	1,000,000
Common stock, par value	$ 0.50	$ 0.50
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	130,194,232	128,176,912
Common stock issuable, shares	47,048	57,409
Series A And Series C [Member]
Preferred stock, shares issued and outstanding	381,500	381,500
Preferred stock, liquidation preference per share	$ 1,000	$ 1,000
Series D Preferred Stock [Member]
Preferred stock, shares issued and outstanding	50,000	50,000
Preferred stock, liquidation preference per share	$ 10,000	$ 10,000