Consolidated Statements of Stockholders' Equity (Unaudited) Statement - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated Other Comprehensive Income	Unrealized investment gain	Currency Translation Adjustments	Treasury stock	Noncontrolling interest
Beginning of period at Dec. 31, 2015		$ 47,024	$ 1,005,455	$ 6,178,070		$ 180,695	$ (247,393)	$ (2,563,605)	$ 32,962
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued including tax benefit			(191)
Restricted stock units expensed			16,350
Stock issued			0
Net income before noncontrolling interests	$ 229,153			228,477					676
Dividends				(30,654)
Unrealized gains on securities not other-than-temporarily impaired	181,888					180,714
Unrealized gains on other-than-temporarily impaired securities						1,183
Net change in period	(57,917)						(57,917)
Stock exercised/vested								1,717
Stock repurchased								(37,424)
Stock incentive plans expensed								0
Contributions									2,923
Other comprehensive income (loss), net of tax	123,971				$ 123,971		(57,917)		(9)
End of period at Jun. 30, 2016			1,021,614	6,375,893	57,282	362,592	(305,310)	(2,599,312)	36,552
Beginning of period at Dec. 31, 2016	5,081,134	$ 47,024	1,037,446	6,595,987		427,154	(371,586)	(2,688,817)	33,926
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued including tax benefit			(1,356)
Restricted stock units expensed			20,788
Stock issued			1,061
Net income before noncontrolling interests	234,247			232,451					1,796
Dividends				(93,372)
Unrealized gains on securities not other-than-temporarily impaired	34,766					33,908
Unrealized gains on other-than-temporarily impaired securities						844
Net change in period	42,982						42,982
Stock exercised/vested								1,276
Stock repurchased								0
Stock incentive plans expensed								728
Contributions									3,695
Other comprehensive income (loss), net of tax	77,748				77,748		42,982		14
End of period at Jun. 30, 2017	$ 5,325,949		$ 1,057,939	$ 6,735,066	$ 133,302	$ 461,906	$ (328,604)	$ (2,686,813)	$ 39,431