Consolidated Balance Sheets (Unauditied) (Parenthetical) (USD $) In Thousands, except Per Share data	Sep. 30, 2011	Dec. 31, 2010
Investments
Total fixed income securities, Available for sale, Cost or amortized cost	$ 5,356,333	$ 4,864,806
Fair value for fixed income securities - held to maturity, at amortized cost	$ 170,556	$ 195,811
SHAREHOLDERS' EQUITY
Common stock, par value	$ 1.00	$ 1.00
Common stock, shares authorized	250,000	250,000
Common stock, shares issued	122,661	120,942
Common stock, shares outstanding	106,511	114,968
Treasury stock	16,150	5,974