Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]	Total Parent Equity [Member]	Non-Controlling Interest in Subsidiaries [Member]
Beginning balance (in shares) at Dec. 31, 2015		150,081,474
Beginning balance at Dec. 31, 2015	$ 3,159,242	$ 150,081	$ 41,353	$ (930,618)	$ 3,885,751	$ 3,146,567	$ 12,675
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	687,240				687,240	687,240
Other comprehensive (loss) income, net of tax	(82,403)			(82,403)		(82,403)
Cash dividends declared	(391,852)				(391,852)	(391,852)
Share-based awards exercised, including tax benefit	(4,126)	$ 341	(4,467)			(4,126)
Share-based awards exercised, including tax benefit (in shares)		340,703
Share-based compensation	19,719		19,719			19,719
Purchase of stock (in shares)		(2,011,755)
Purchase of stock	(181,417)	$ (2,012)			(179,405)	(181,417)
Noncontrolling interest activities	953						953
Ending balance (in shares) at Dec. 31, 2016		148,410,422
Ending balance at Dec. 31, 2016	3,207,356	$ 148,410	56,605	(1,013,021)	4,001,734	3,193,728	13,628
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	616,757				616,757	616,757
Other comprehensive (loss) income, net of tax	160,429			160,429		160,429
Cash dividends declared	(396,891)				(396,891)	(396,891)
Share-based awards exercised, including tax benefit	(5,239)	$ 132	(5,371)			(5,239)
Share-based awards exercised, including tax benefit (in shares)		131,232
Share-based compensation	16,892		16,892			16,892
Purchase of stock (in shares)		(1,889,039)
Purchase of stock	(173,524)	$ (1,889)			(171,635)	(173,524)
Noncontrolling interest activities	38,376						38,376
Ending balance (in shares) at Dec. 31, 2017		146,652,615
Ending balance at Dec. 31, 2017	3,464,156	$ 146,653	68,126	(852,592)	4,049,965	3,412,152	52,004
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	810,474				810,474	810,474
Other comprehensive (loss) income, net of tax	(262,486)			(262,486)		(262,486)
Cash dividends declared	(422,352)				(422,352)	(422,352)
Share-based awards exercised, including tax benefit	$ (10,227)	$ 235	(10,462)			(10,227)
Share-based awards exercised, including tax benefit (in shares)	772,000	235,058
Share-based compensation	$ 20,716		20,716			20,716
Purchase of stock (in shares)		(951,060)
Purchase of stock	(91,983)	$ (951)			(91,032)	(91,983)
Noncontrolling interest activities	(30,464)						(30,464)
Ending balance (in shares) at Dec. 31, 2018		145,936,613
Ending balance at Dec. 31, 2018	$ 3,471,991	$ 145,937	$ 78,380	$ (1,115,078)	$ 4,341,212	$ 3,450,451	$ 21,540