Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Securities Available for Sale, Amortized Cost	$ 2,128,013	$ 4,401,345
Held to maturity securities	1,889,136
Property and equipment, accumulated depreciation	$ 155,777	$ 148,780
Common stock, par value per share	$ 3.33	$ 3.33
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares issued	84,781,894	84,781,894
Common stock, shares outsanding	84,705,496	84,705,496