Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 169,349	$ 32,789	$ 389,667	$ 82,833
Other comprehensive income (loss):
Change in unrealized gains on securities, net of taxes of $(62,503), $116,577, $(77,339) and $88,228, respectively	115,940	(223,064)	145,812	(165,605)
Change in other-than-temporary impairment gains, net of taxes of $(104), $152, $571 and $632, respectively	192	(281)	(1,059)	(1,175)
Change in foreign currency translation, net of taxes of $(46), $(712), $(1,655) and $1,943, respectively	(14,524)	20,151	(2,664)	(45,800)
Pension plan curtailment and amortization of pension and postretirement unrecognized net periodic benefit cost, net of taxes of $(219), $(1,409), $(35,870) and $(2,818), respectively	406	2,616	66,616	5,232
Total other comprehensive income (loss)	102,014	(200,578)	208,705	(207,348)
Total comprehensive income (loss)	$ 271,363	$ (167,789)	$ 598,372	$ (124,515)