Supplemental Financial Statement Data (Schedule of Other Operating Cost and Expense, by Component) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Income and Expenses [Abstract]
Amortization of deferred policy acquisition costs	$ 904,955	$ 1,001,611	$ 915,246
Insurance operating expenses	1,206,058	1,088,690	1,183,635
Insurance service expenses	85,724	101,317	118,357
Net foreign currency losses (gains)	363	(30,715)	(27,067)
Debt extinguishment costs	8,440	0	0
Other costs and expenses	184,852	201,179	193,050
Total	$ 2,390,392	$ 2,362,082	$ 2,383,221