Realized and Unrealized Investment Gains (Losses) (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Realized and Unrealized Investment Gains Losses [Line Items]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	$ (7,730)	$ (25,029)	$ (135,184)	$ 163,651
Income tax benefit (expense)	12,229	12,117	56,354	(55,419)
Noncontrolling interests	94	(82)	106	(119)
Total change in unrealized gains	4,593	(12,994)	(78,724)	108,113
Debt Securities [Member]
Realized and Unrealized Investment Gains Losses [Line Items]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	2,449	10,722	(102,863)	190,242
Debt Securities Previously Impaired [Member]
Realized and Unrealized Investment Gains Losses [Line Items]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	50	188	73	941
Equity securities available for sale
Realized and Unrealized Investment Gains Losses [Line Items]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	(2,353)	(27,548)	(15,977)	(19,215)
Investment funds
Realized and Unrealized Investment Gains Losses [Line Items]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	$ (7,876)	$ (8,391)	$ (16,417)	$ (8,317)