Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Sep. 30, 2011	Dec. 31, 2010
Consolidated Balance Sheets [Abstract]
Amortized cost on fixed maturities trading investments	$ 2,381,040	$ 2,617,656
Cost - equity security trading investments	368,856	336,757
Cost - short-term investments	$ 251,751	$ 143,378
Common Stock
Common stock, no par value
Common stock, shares authorized	70,000	70,000
Common stock, shares issued	54,827	54,803
Common stock, shares outstanding	54,827	54,803