CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Comprehensive income
Net Income (Loss) Attributable to Parent	$ 715,842	$ 1,822,181	$ 701,443
Other comprehensive income (loss), net of tax:
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(79,775)	69,126	8,610
Net unrealized investment gains (losses)	(1,344,502)	698,078	419,336
Change in other-than-temporary impairment losses on fixed maturity securities		(244)	(947)
Defined benefit pension and postretirement plan adjustments	(18)	726	3,099
Total other comprehensive income (loss), net of tax	(1,424,295)	767,930	431,045
Total comprehensive income (loss)	$ (708,453)	$ 2,590,111	$ 1,132,488