Consolidated Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Income and Comprehensive Income [Abstract]
Net earnings	$ 107,911	$ 105,850
Investment gains (losses):
Investment gains (losses) during the period	86,080	(30,395)
Income tax charge (benefit)	30,570	(10,327)
Investments gains (losses), net of tax	55,510	(20,068)
Less reclassification adjustments for:
Gains included in net earnings	20,246	8,570
Income tax charge	7,086	2,999
Gains included in net earnings, net of tax	13,160	5,571
Net unrealized investment gains (losses)	42,350	(25,639)
Foreign currency translation adjustment	788	(2,056)
Income tax benefit	(432)	(524)
Foreign currency translation adjustment, net of tax	1,220	(1,532)
Other comprehensive income (loss)	43,570	(27,171)
Comprehensive income	$ 151,481	$ 78,679