CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income (loss)	Treasury Stock	Noncontrolling Interest
Beginning Balance (in shares) at Dec. 31, 2012		43,102				2,130
Beginning Balance at Dec. 31, 2012	$ 1,781,537	$ 43,102	$ 394,384	$ 1,601,460	$ (132,048)	$ (127,948)	$ 2,587
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	151,748			150,881			867
Cash dividends ($1.36 per share)	(55,917)			(55,917)
Other comprehensive income	20,964				21,193		(229)
Distributions to noncontrolling interest shareholders	(736)						(736)
Shares issued under compensation plans (in shares)		141				65
Shares issued under compensation plans	18,374	$ 141	14,963			$ 3,270
Deferred compensation (in shares)						(1)
Deferred compensation	46		(9)			$ 55
Ending Balance at Dec. 31, 2013	1,916,016	$ 43,243	409,338	1,696,424	(110,855)	$ (124,623)	2,489
Ending Balance (in shares) at Dec. 31, 2013		43,243				2,064
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	188,751			187,679			1,072
Cash dividends ($1.36 per share)	(56,258)			(56,258)
Other comprehensive income	(150,117)				(150,040)		(77)
Distributions to noncontrolling interest shareholders	(1,094)						(1,094)
Settlement of convertible notes (in shares)						(1)
Settlement of convertible notes	1		(42)			$ 43
Settlement of note hedges associated with convertible notes (in shares)						1
Settlement of note hedges associated with convertible notes	2		79			$ (77)
Shares issued under compensation plans (in shares)		177				81
Shares issued under compensation plans	16,277	$ 177	$ 13,019			$ 3,081
Deferred compensation (in shares)						(2)
Deferred compensation	121					$ 121
Ending Balance at Dec. 31, 2014	1,913,699	$ 43,420	$ 422,394	1,827,845	(260,895)	$ (121,455)	2,390
Ending Balance (in shares) at Dec. 31, 2014		43,420				1,981
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	245,713			244,863			850
Cash dividends ($1.36 per share)	(56,532)			(56,532)
Other comprehensive income	(110,305)				(110,229)		(76)
Distributions to noncontrolling interest shareholders	(1,343)						(1,343)
Settlement of convertible notes (in shares)						(2)
Settlement of convertible notes	5		(128)			$ 133
Settlement of note hedges associated with convertible notes (in shares)						2
Settlement of note hedges associated with convertible notes	1		270			$ (269)
Shares issued under compensation plans (in shares)		97				70
Shares issued under compensation plans	19,782	$ 97	17,591			$ 2,094
Deferred compensation (in shares)						(3)
Deferred compensation	73					$ 73
Ending Balance at Dec. 31, 2015	$ 2,011,093	$ 43,517	$ 440,127	$ 2,016,176	$ (371,124)	$ (119,424)	$ 1,821
Ending Balance (in shares) at Dec. 31, 2015		43,517				1,908