Realized and Unrealized Investment Gains (Losses) (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Financing Receivable, Allowance for Credit Losses, Period Increase (Decrease)	$ 7,280	$ 9	$ 14,053	$ (541)
Change in unrealized gains (losses) before income taxes and noncontrolling interests	99,924	39,515	194,520	121,068
Income tax expense	(34,963)	(14,268)	(68,000)	(42,893)
Noncontrolling interests	(43)	1	(71)	(11)
Total change in unrealized gains	64,918	25,248	126,449	78,164
Fixed Maturities Securities [Member]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	96,077	115,933	186,637	187,851
Non-Credit Portion of OTTI Recognized In Other Comprehensive Income [Member]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	2,483	(1,300)	4,416	(1,956)
Equity Securities Available For Sale [Member]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	(2,891)	(65,861)	186	(59,760)
Investment Funds [Member]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	$ 4,255	$ (9,257)	$ 3,281	$ (5,067)