Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fixed maturities, available-for-sale, amortized cost	$ 2,294,763	$ 2,323,959
Equity securities, available-for-sale, cost	133,968	154,843
Short-term investments, amortized cost	$ 243,730	$ 179,527
Preferred stock, par value	$ 0.10	$ 0.10
Preferred stock, authorized shares	1,000,000	1,000,000
Preferred stock, issued shares	0	0
Common stock, par value	$ 0.10	$ 0.10
Common stock, authorized shares	50,000,000	50,000,000
Common stock, issued shares	17,903,198	17,792,846
Treasury stock, shares	3,511,380	3,511,380