Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income before noncontrolling interests	$ 603,485	$ 504,107	$ 649,603
Other comprehensive gain (loss):
Change in unrealized translation adjustments	(124,193)	(124,744)	(62,125)
Change in unrealized investment gains (losses), net of taxes	246,518	(125,542)	49,666
Change in unrecognized pension obligation, net of taxes	0	0	6,651
Other comprehensive gain (loss)	122,325	(250,286)	(5,808)
Comprehensive income	725,810	253,821	643,795
Comprehensive loss (income) to the noncontrolling interest	1,510	(375)	(752)
Comprehensive income to common shareholders	$ 727,320	$ 253,446	$ 643,043