Supplemental Financial Statement Information (Schedule of Other Operating Cost and Expense, by Component) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Amortization of deferred policy acquisition costs	$ 1,155,954	$ 1,102,492	$ 1,053,397
Operating insurance expenses	933,249	903,006	843,133
Service company expenses	138,908	127,365	102,726
Net foreign currency (gains) losses	(11,904)	400	(27)
Other costs and expenses		156,487	158,227
Total	2,395,619	$ 2,289,750	$ 2,157,456
Other Expense [Member]
Other costs and expenses	$ 179,412