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	Non- controlling Interest
Beginning Balance (in shares) at Dec. 31, 2013		43,243				2,064
Beginning Balance at Dec. 31, 2013	$ 1,916,016	$ 43,243	$ 409,338	$ 1,696,424	$ (110,855)	$ (124,623)	$ 2,489
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 loss	(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 and warrants	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 loss	(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 and warrants	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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	237,841			237,377			464
Cash dividends ($1.36 per share)	(58,960)			(58,960)
Other comprehensive loss	(66,804)				(66,761)		(43)
Distributions to noncontrolling interest shareholders	(464)						(464)
Acquisition of noncontrolling interest	(9,231)		(6,621)			$ (832)	(1,778)
Settlement of convertible notes (in shares)		(2,168)				(430)
Settlement of convertible notes	3,296	$ 2,168	(32,004)			$ 33,132
Settlement of note hedges associated with convertible notes (in shares)						316
Settlement of note hedges associated with convertible notes and warrants	2		86,048			$ (86,046)
Reclassification of convertible notes to mezzanine equity	(1,824)		(1,824)
Shares issued under compensation plans (in shares)		129				(51)
Shares issued under compensation plans	22,492	$ 129	21,074			$ 1,289
Deferred compensation (in shares)						2
Deferred compensation	76					$ 76
Ending Balance at Dec. 31, 2016	$ 2,137,517	$ 45,814	$ 506,800	$ 2,194,593	$ (438,717)	$ (170,973)	$ 0
Ending Balance (in shares) at Dec. 31, 2016		45,814				1,741