Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Fixed maturities, available-for-sale, amortized cost	$ 2,001,865	$ 2,034,765
Equity securities, available-for-sale, cost	$ 92,017	$ 85,004
Preferred stock, par value	$ 0.10	$ 0.10
Preferred stock, authorized shares	1,000,000	1,000,000
Preferred stock, issued shares
Common stock, par value	$ 0.10	$ 0.10
Common stock, authorized shares	50,000,000	50,000,000
Common stock, issued shares	17,641,357	17,558,046
Treasury stock, shares	3,511,380	3,511,380