Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net income	$ 186,566	$ 184,425	$ 371,911	$ 358,025
Unrealized gains (losses) on fixed maturities:
Unrealized gains (losses) on fixed maturities	718,236	(425,805)	1,413,175	(1,041,487)
Less applicable tax (expense) benefit	(150,829)	89,423	(296,765)	218,712
Unrealized gains (losses) on investments, net of tax	567,407	(336,382)	1,116,410	(822,775)
Unrealized gains (losses) attributable to deferred acquisition costs	170	2,041	(3,029)	2,491
Less applicable tax (expense) benefit	(35)	(429)	636	(523)
Unrealized gains (losses) attributable to deferred acquisition costs, net of tax	135	1,612	(2,393)	1,968
Foreign exchange translation adjustments, other than securities	(38)	(6,217)	3,051	(7,516)
Less applicable tax (expense) benefit	7	1,303	(640)	1,579
Foreign exchange translation adjustments, other than securities, net of tax	(31)	(4,914)	2,411	(5,937)
Pension:
Amortization of pension costs	2,118	3,778	4,238	7,556
Pension adjustments	2,118	3,778	4,238	7,556
Less applicable tax (expense) benefit	(446)	(794)	(891)	(1,587)
Pension adjustments, net of tax	1,672	2,984	3,347	5,969
Other comprehensive income (loss)	569,183	(336,700)	1,119,775	(820,775)
Comprehensive income (loss)	755,749	(152,275)	1,491,686	(462,750)
Securities
Unrealized gains (losses) on fixed maturities:
Unrealized holding gains (losses) arising during period	714,862	(417,616)	1,408,344	(1,029,164)
Reclassifications adjustments included in net income	(843)	(8,561)	(3,287)	(9,257)
Foreign exchange adjustment on securities recorded at fair value	626	(679)	484	(1,264)
Unrealized gains (losses) on fixed maturities	714,645	(426,856)	1,405,541	(1,039,685)
Other
Unrealized gains (losses) on fixed maturities:
Unrealized holding gains (losses) arising during period	$ 3,591	$ 1,051	$ 7,634	$ (1,802)