Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Retained Earnings [Member]	Total Parent Equity [Member]	Non-Controlling Interest in Subsidiaries [Member]
Beginning Balance at Dec. 31, 2012	$ 3,008,179	$ 154,841		$ (501,492)	$ 3,344,538	$ 2,997,887	$ 10,292
Beginning Balance, Shares at Dec. 31, 2012		154,841,438
Net income	684,959				684,959	684,959
Other comprehensive (loss) income, net of tax	103,837			103,837		103,837
Cash dividends declared	(332,322)				(332,322)	(332,322)
Share-based awards exercised, including tax benefit	2,737	$ 450	$ 2,287			2,737
Share-based awards exercised, including tax benefit, Shares		449,986
Share-based compensation	12,648		12,648			12,648
Purchase of stock	(120,672)	$ (1,518)			(119,154)	(120,672)
Purchase of stock, Shares		(1,518,326)
Noncontrolling interest activities	(598)						(598)
Ending Balance at Dec. 31, 2013	3,358,768	$ 153,773	14,935	(397,655)	3,578,021	3,349,074	9,694
Ending Balance, Shares at Dec. 31, 2013		153,773,098
Net income	711,286				711,286	711,286
Other comprehensive (loss) income, net of tax	(322,556)			(322,556)		(322,556)
Cash dividends declared	(352,564)				(352,564)	(352,564)
Share-based awards exercised, including tax benefit	(4,285)	$ 475	(4,760)			(4,285)
Share-based awards exercised, including tax benefit, Shares		474,800
Share-based compensation	16,239		16,239			16,239
Purchase of stock	(95,946)	$ (1,135)			(94,811)	(95,946)
Purchase of stock, Shares		(1,134,856)
Noncontrolling interest activities	1,422						1,422
Ending Balance at Dec. 31, 2014	3,312,364	$ 153,113	26,414	(720,211)	3,841,932	3,301,248	11,116
Ending Balance, Shares at Dec. 31, 2014		153,113,042
Net income	705,672				705,672	705,672
Other comprehensive (loss) income, net of tax	(210,407)			(210,407)		(210,407)
Cash dividends declared	(372,840)				(372,840)	(372,840)
Share-based awards exercised, including tax benefit	(2,548)	$ 230	(2,778)			(2,548)
Share-based awards exercised, including tax benefit, Shares		229,958
Share-based compensation	17,717		17,717			17,717
Purchase of stock	(292,275)	$ (3,262)			(289,013)	(292,275)
Purchase of stock, Shares		(3,261,526)
Noncontrolling interest activities	1,559						1,559
Ending Balance at Dec. 31, 2015	$ 3,159,242	$ 150,081	$ 41,353	$ (930,618)	$ 3,885,751	$ 3,146,567	$ 12,675
Ending Balance, Shares at Dec. 31, 2015		150,081,474