CONSOLIDATED CONDENSED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
CONSOLIDATED CONDENSED BALANCE SHEETS
Fixed maturities, amortized cost	$ 27,220,069	$ 26,681,324
Fixed maturities at amortized cost, fair value	334,579	319,163
Equity securities, cost	406,937	409,376
Mortgage loans, related to securitizations	728,671	765,520
Investment real estate, accumulated depreciation	1,087	1,017
Accounts and premiums receivable, allowance for uncollectible amounts	4,347	4,290
Property and equipment, accumulated depreciation	107,459	105,789
Preferred Stock, par value (in dollars per share)	$ 1	$ 1
Preferred Stock, shares authorized (in shares)	4,000,000	4,000,000
Preferred Stock, shares Issued (in shares)	0	0
Common Stock, par value (in dollars per share)	$ 0.50	$ 0.50
Common Stock, shares authorized (in shares)	160,000,000	160,000,000
Common Stock, shares issued (in shares)	88,776,960	88,776,960
Treasury stock, shares (in shares)	10,327,889	10,639,467
Net unrealized gains (losses) on investments, income tax	899,657	978,656
Net unrealized (losses) gains relating to other-than-temporary impaired investments for which a portion has been recognized in earnings, income tax	2,072	(2,147)
Accumulated loss - derivatives, income tax	(166)	(1,883)
Postretirement benefits liability adjustment, income tax	$ (40,390)	$ (39,468)