Realized and Unrealized Investment Gains (Losses) (Realized and Unrealized Investment Gains (Losses) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule of Cost-method Investments [Line Items]
Fixed maturity securities, gains	$ 10,996,000	$ 14,955,000
Fixed maturity securities, losses	(5,966,000)	(543,000)
Equity securities available for sale	15,245,000	26,238,000
Realized gains on investment funds	194,000.000	1,310,000.000
Other	(500,000)	1,517,000
Sales of investment funds	19,969,000	43,477,000
Less investment impairments recognized in other comprehensive income	0	6,998,000
OTTI	0.000	(2,984,000.000)
Change in valuation allowance, net of other-than-temporary impairments	0	4,014,000
Net investment gains	19,969,000	47,491,000
Income tax expense	(6,989,000)	(16,409,000)
Total net investment gains	$ 12,980,000	$ 31,082,000