Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets [Abstract]
Securities available for sale, Amortized Cost	$ 4,401,345	$ 1,445,721
Property and equipment, accumulated depreciation	$ 148,780	$ 125,383
Common stock, par value per share	$ 3.33	$ 3.33
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares issued	84,705,496	36,893,276
Common stock, shares outstanding	84,705,496	36,893,276