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Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheets [Abstract]
Amortized cost on fixed maturities trading investments	$ 2,364,561	$ 2,345,620
Cost - equity security trading investments	385,990	388,417
Cost - short-term investments	$ 227,340	$ 236,433
Common Stock
Common stock, no par value
Common stock, shares authorized	70,000,000	70,000,000
Common stock, shares issued	54,883,000	54,856,000
Common stock, shares outstanding	54,883,000	54,856,000

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Issuance value per share of no-par value common stock; generally not indicative of the fair market value per share.

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