Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Amortized cost of available-for-sale securities	$ 376,942	$ 306,193
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	15,000,000	15,000,000
Preferred stock, shares issued	12,500,000	7,500,000
Preferred stock, shares outstanding	12,500,000	7,500,000
Common stock, par value	$ 2.50	$ 2.50
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	11,424,390	11,424,390
Preferred Stock Series A [Member]
Preferred stock, par value	$ 10.00	$ 10.00
Preferred stock, shares authorized	200,000	200,000
Preferred stock, shares issued	51,500	51,500
Preferred stock, shares outstanding	51,500	51,500
Preferred stock, stated value	$ 1,000	$ 1,000