CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Common Shares	Capital in Excess of Par Value	Accumulated Other Comprehensive Income	Retained Earnings	Treasury Shares	Non-controlling Interest	Total
Balance at the beginning of the period at Dec. 31, 2012	$ 319	$ 2,337,244	$ 340,143	$ 4,211,850	$ (944,627)	$ 12,188	$ 5,957,117
Balance (in shares) at Dec. 31, 2012	318,813,000
Increase (Decrease) in Equity
Net income (loss)				139,982		7,180	147,162
Dividends to shareholders				(47,168)			(47,168)
Other comprehensive income (loss), net of tax			(124,003)			(932)	(124,935)
Issuance of common shares for stock options exercised, net of surrender of unexercised stock options	$ 1	5,382					5,383
Issuance of common shares for stock options exercised, net of surrender of unexercised stock options (in shares)	577,000
Share-based compensation		53,255					53,255
Other	$ 4	(3,296)				(6,345)	(9,637)
Other (in shares)	4,321,000
Balance at the end of the period at Dec. 31, 2013	$ 324	2,392,585	216,140	4,304,664	(944,627)	12,091	5,981,177
Balance (in shares) at Dec. 31, 2013	323,711,000
Increase (Decrease) in Equity
Net income (loss)				(670,659)		1,415	(669,244)
Dividends to shareholders				(59,145)			(59,145)
Redemption of subsidiary preferred stock				(1,688)			(1,688)
Repurchase of treasury shares					(250,037)		(250,037)
Other comprehensive income (loss), net of tax			(138,618)			(1,017)	(139,635)
Issuance of common shares for stock options exercised, net of surrender of unexercised stock options	$ 3	30,260					30,263
Issuance of common shares for stock options exercised, net of surrender of unexercised stock options (in shares)	3,036,000
Share-based compensation		37,157					37,157
Other	$ 1	(7,741)				(2,319)	(10,059)
Other (in shares)	1,449,000
Balance at the end of the period at Dec. 31, 2014	$ 328	2,452,261	77,522	3,573,172	(1,194,664)	10,170	4,918,789
Balance (in shares) at Dec. 31, 2014	328,196,000
Increase (Decrease) in Equity
Net income (loss)				(372,675)		381	(372,294)
Dividends to shareholders				(69,363)			(69,363)
Repurchase of treasury shares					(99,598)		(99,598)
Other comprehensive income (loss), net of tax			(125,115)			(1,461)	(126,576)
Issuance of common shares for stock options exercised, net of surrender of unexercised stock options		1,296					1,296
Issuance of common shares for stock options exercised, net of surrender of unexercised stock options (in shares)	141,000
Share-based compensation		47,863					47,863
Other	$ 3	(8,320)				2,068	(6,249)
Other (in shares)	2,189,000
Balance at the end of the period at Dec. 31, 2015	$ 331	$ 2,493,100	$ (47,593)	$ 3,131,134	$ (1,294,262)	$ 11,158	$ 4,293,868
Balance (in shares) at Dec. 31, 2015	330,526,000