Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Investments
Total fixed maturity securities, Available for sale, Cost or amortized cost	$ 5,712,890	$ 5,385,432
Fair value for fixed maturity securities - held to maturity, at amortized cost	0	163,136
Fair value for equity securities-available for sale, at cost	92,580	0
Other investments, amortized cost	$ 38,053	$ 38,230
SHAREHOLDERS' EQUITY
Common stock, par value	$ 1.00	$ 1.00
Common stock, shares authorized	250,000	250,000
Common stock, shares issued	123,449	122,720
Common stock, shares outstanding	100,737	104,101
Treasury stock	22,712	18,619