Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 32,789	$ 143,610	$ 82,833	$ 280,855
Other comprehensive (loss) income:
Change in unrealized gains on securities, net of taxes of $116,577, $(69,980), $88,228 and $(156,856), respectively	(223,064)	139,934	(165,605)	310,967
Change in other-than-temporary impairment gains, net of taxes of $152, $(400), $632 and $(1,284), respectively	(281)	744	(1,175)	2,384
Change in foreign currency translation, net of taxes of $(712), $9,012, $1,943 and $12,354, respectively	20,151	37,883	(45,800)	19,829
Amortization of pension and postretirement unrecognized net periodic benefit cost, net of taxes of $(1,409), $(1,094), $(2,818) and $(2,188), respectively	2,616	2,030	5,232	4,062
Total other comprehensive (loss) income	(200,578)	180,591	(207,348)	337,242
Total comprehensive (loss) income	$ (167,789)	$ 324,201	$ (124,515)	$ 618,097