Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Securities - held-to-maturity, at amortized cost (fair value)	$ 507,699	$ 625,643
Common stock, stated value	$ 1	$ 1
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	94,654,000	87,183,000
Common stock, shares outstanding	94,654,000	87,183,000
Preferred Stock, Series A [Member]
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0