Realized and Unrealized Investment Gains and Losses (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized gains (losses) before income taxes and noncontrolling interests	$ (399,122)	$ 135,282	$ 147,998
Income tax expense	138,058	(47,966)	(52,381)
Noncontrolling interests	(28)	(77)	55
Total change in unrealized gains and losses	(261,092)	87,239	95,672
Debt Securities
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized gains (losses) before income taxes and noncontrolling interests	(401,812)	162,220	209,467
Debt Securities Previously Impaired
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized gains (losses) before income taxes and noncontrolling interests	1,076	4,631	(3,604)
Equity securities available for sale
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized gains (losses) before income taxes and noncontrolling interests	11,864	(33,199)	(55,772)
Investment funds
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized gains (losses) before income taxes and noncontrolling interests	$ (10,250)	$ 1,630	$ (2,093)