Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 80,937	$ 64,095	$ 153,477	$ 135,275
Other comprehensive income, net of tax:
Unrealized (loss) gain on securities	(14,886)	5,839	10,918	(34,906)
Unrealized gain on securities for which credit losses have been recognized in earnings	151	400	586	420
Foreign currency translation adjustment	(12,557)	8,968	(6,985)	(7,648)
Pension benefit adjustment	907	4,121	8,690	12,408
Total other comprehensive (loss) income, net of tax	(26,385)	19,328	13,209	(29,726)
Comprehensive income	54,552	83,423	166,686	105,549
Less: Comprehensive income attributable to noncontrolling interests	235	207	464	530
Comprehensive income attributable to the Company	$ 54,317	$ 83,216	$ 166,222	$ 105,019