Realized and Unrealized Investment Gains (Losses) (Realized and Unrealized Investment Gains (Losses) (Details) (USD $)	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Realized And Unrealized Investment Gains (Losses)
Fixed maturity securities, gains	$ 14,955,000		$ 5,880,000
Fixed maturity securities, losses	(543,000)		(1,493,000)
Equity securities available for sale	26,238,000		23,932,000
Other	1,517,000		0
Sales of investment funds	1,310,000		965,000
Provision for OTTI	4,014,000	[1]	0	[1]
Net investment gains	47,491,000		29,284,000
Income tax expense	(16,409,000)		(10,494,000)
Total net investment gains	31,082,000		18,790,000
Financing Receivable, Allowance for Credit Losses, Period Increase (Decrease)	6,896,000		0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, No Previous Impairment	$ 3,000,000

[1] Represents reduction of valuation allowance of $7 million, net of other-than-temporary-impairment of