Consolidated Statement Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 65,744	$ (7,022)	$ 32,789	$ 50,044	$ 49,755	$ 140,297	$ 143,610	$ 137,245	$ 141,555	$ 470,907	$ 488,907
Other comprehensive (loss) income:
Change in unrealized gains on securities, net of taxes of $158,653, $(135,743), and $231,472, respectively									(297,639)	267,011	(455,808)
Change in other-than-temporary impairment gains, net of taxes of $2,240, $(90), and $(1,382), respectively									(4,160)	167	2,566
Change in foreign currency translation, net of taxes of $5,100, $2,745, and $8,162, respectively									(143,023)	(88,944)	(45,649)
Amortization of pension and postretirement unrecognized net periodic benefit cost and change in funded status, net of taxes of $(4,091), $26,534, and $(51,302), respectively									7,604	(49,297)	95,318
Total other comprehensive (loss) income									(437,218)	128,937	(403,573)
Total comprehensive (loss) income									$ (295,663)	$ 599,844	$ 85,334