Condensed Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Total Parent Equity	Non-controlling Interests in Subsidiaries
Beginning balance (in shares) at Dec. 31, 2017		146,652,615
Beginning 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	623,775				623,775	623,775
Other comprehensive loss, net of tax	(109,685)			(109,685)		(109,685)
Cash dividends declared	(316,984)				(316,984)	(316,984)
Share-based awards exercised, including tax benefit (in shares)		125,946
Share-based awards exercised, including tax benefit	(5,860)	$ 125	(5,985)			(5,860)
Share-based compensation	15,417		15,417			15,417
Purchase of stock (in shares)		(19,288)
Purchase of stock	(1,918)	$ (19)			(1,899)	(1,918)
Noncontrolling interest activities	21						21
Ending balance (in shares) at Sep. 30, 2018		146,759,273
Ending balance at Sep. 30, 2018	3,663,079	$ 146,759	77,558	(962,277)	4,349,014	3,611,054	52,025
Beginning balance (in shares) at Jun. 30, 2018		146,752,732
Beginning balance at Jun. 30, 2018	3,562,327	$ 146,753	72,211	(943,351)	4,236,359	3,511,972	50,355
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	220,227				220,227	220,227
Other comprehensive loss, net of tax	(18,926)			(18,926)		(18,926)
Cash dividends declared	(105,673)				(105,673)	(105,673)
Share-based awards exercised, including tax benefit (in shares)		25,829
Share-based awards exercised, including tax benefit	(1,010)	$ 25	(1,035)			(1,010)
Share-based compensation	6,382		6,382			6,382
Purchase of stock (in shares)		(19,288)
Purchase of stock	(1,918)	$ (19)			(1,899)	(1,918)
Noncontrolling interest activities	1,670						1,670
Ending balance (in shares) at Sep. 30, 2018		146,759,273
Ending balance at Sep. 30, 2018	3,663,079	$ 146,759	77,558	(962,277)	4,349,014	3,611,054	52,025
Beginning balance (in shares) at Dec. 31, 2018		145,936,613
Beginning balance at Dec. 31, 2018	3,471,991	$ 145,937	78,380	(1,115,078)	4,341,212	3,450,451	21,540
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	612,167				612,167	612,167
Other comprehensive loss, net of tax	(30,976)			(30,976)		(30,976)
Cash dividends declared	(333,521)				(333,521)	(333,521)
Share-based awards exercised, including tax benefit (in shares)		144,709
Share-based awards exercised, including tax benefit	(7,495)	$ 145	(7,640)			(7,495)
Share-based compensation	19,820		19,820			19,820
Purchase of stock (in shares)		(788,207)
Purchase of stock	(73,052)	$ (789)			(72,263)	(73,052)
Noncontrolling interest activities	1,006						1,006
Ending balance (in shares) at Sep. 30, 2019		145,293,115
Ending balance at Sep. 30, 2019	3,664,737	$ 145,293	90,560	(1,268,580)	4,674,918	3,642,191	22,546
Beginning balance (in shares) at Jun. 30, 2019		146,078,369
Beginning balance at Jun. 30, 2019	3,687,975	$ 146,078	83,949	(1,195,179)	4,630,480	3,665,328	22,647
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	227,487				227,487	227,487
Other comprehensive loss, net of tax	(73,401)			(73,401)		(73,401)
Cash dividends declared	(110,786)				(110,786)	(110,786)
Share-based awards exercised, including tax benefit (in shares)		2,953
Share-based awards exercised, including tax benefit	(124)	$ 4	(128)			(124)
Share-based compensation	6,739		6,739			6,739
Purchase of stock (in shares)		(788,207)
Purchase of stock	(73,052)	$ (789)			(72,263)	(73,052)
Noncontrolling interest activities	(101)						(101)
Ending balance (in shares) at Sep. 30, 2019		145,293,115
Ending balance at Sep. 30, 2019	$ 3,664,737	$ 145,293	$ 90,560	$ (1,268,580)	$ 4,674,918	$ 3,642,191	$ 22,546