Investment Information (Net Realized Gains and Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Net realized gains and losses:
Available for sale securities, gross gains on investment sales	$ 67,020		$ 48,012
Available for sale securities, gross losses on investment sales	(25,056)		(17,936)
Derivative instruments	(378)	[1]	(4,669)	[1]
Other	1,046		1,062
Net realized gains	58,340		44,121
Fixed Maturities
Net realized gains and losses:
Change in fair value of assets and liabilities accounted for using the fair value option	5,058		8,217
Equity securities
Net realized gains and losses:
Change in fair value of assets and liabilities accounted for using the fair value option	699		3,387
Other investments
Net realized gains and losses:
Change in fair value of assets and liabilities accounted for using the fair value option	9,951		3,753
TALF investments
Net realized gains and losses:
Change in fair value of assets and liabilities accounted for using the fair value option	0		1,224
TALF borrowings
Net realized gains and losses:
Change in fair value of assets and liabilities accounted for using the fair value option	$ 0		$ 1,071

[1] See Note 9 for information on the Company’s derivative instruments.