Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 220,318	$ 50,044
Other comprehensive income (loss):
Change in unrealized gains on securities, net of taxes of $(14,836) and $(28,349), respectively	29,872	57,459
Change in other-than-temporary impairment gains, net of taxes of $674 and $481, respectively	(1,251)	(894)
Change in foreign currency translation, net of taxes of $(1,609) and $2,654, respectively	11,860	(65,951)
Pension plan curtailment and amortization of pension and postretirement unrecognized net periodic benefit cost, net of taxes of $(35,651) and $(1,409), respectively	66,210	2,616
Total other comprehensive income (loss)	106,691	(6,770)
Total comprehensive income	$ 327,009	$ 43,274