Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Income and Comprehensive Income [Abstract]
Net earnings	$ 80,417	$ 97,136	$ 193,334	$ 205,047
Investment gains (losses):
Investment gains (losses) during the period	(97,625)	93,745	(77,616)	179,825
Income tax charge (benefit)	(34,525)	33,248	(27,320)	63,818
Investments gains (losses), net of tax	(63,100)	60,497	(50,296)	116,007
Less reclassification adjustments to:
Net realized investment gain	573	4,905	13,759	25,151
Income tax expense	201	1,717	4,816	8,803
Total reclassifications included in net earnings, net of tax	372	3,188	8,943	16,348
Net unrealized investment gains (losses)	(63,472)	57,309	(59,239)	99,659
Foreign currency translation adjustment	1,992	903	(5,060)	1,691
Income tax charge (benefit)	70	11	3	(421)
Foreign currency translation adjustment, net of tax	1,922	892	(5,063)	2,112
Other comprehensive income (loss)	(61,550)	58,201	(64,302)	101,771
Comprehensive income	$ 18,867	$ 155,337	$ 129,032	$ 306,818