Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets [Abstract]
Amortized cost on fixed maturities trading investments	$ 2,345,620	$ 2,617,656
Cost - equity security trading investments	388,417	336,757
Cost - short-term investments	$ 236,433	$ 143,378
Common Stock
Common stock, par value	$ 0	$ 0
Common stock, shares Authorized	70,000	70,000
Common stock, shares issued	54,856	54,803
Common stock, shares outstanding	54,856	54,803