Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Investments
Fixed maturity securities, available for sale, amortized cost	$ 5,910,038	$ 5,921,487
Equity securities, available for sale, cost	$ 391,779	$ 464,388
SHAREHOLDERS' EQUITY
Common stock, par value	$ 1.00	$ 1.00
Common stock, shares authorized	250,000	250,000
Common stock, shares issued	126,062	125,577
Common stock, shares outstanding	100,085	100,336
Treasury stock	25,977	25,241