Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fixed maturities, available for sale, amortized cost	$ 11,963,406	$ 10,924,244
Equity securities, cost	14,875	14,875
Long term debt, fair value	$ 1,191,320	$ 947,142
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	320,000,000	320,000,000
Common stock, shares issued	105,812,123	112,312,123
Common stock, shares held in treasury	11,576,487	11,732,658