CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Non-controlling Interests [Member]	Total
Balance at Dec. 31, 2009	$ 4,650	$ 316,494	$ 836,062	$ 3,193	$ (436,238)	$ 23,582	$ 747,743
Net income (loss)	0	0	66,869	0	0	3,017	69,886
Sale of 50% Interest							0
Currency translation adjustment	0	0	0	(9,195)	0	1,022	(8,173)
Unamortized gains (losses) and prior service cost	0	0	0	347	0	0	347
Cash flow hedges:
Net derivative gains (losses) arising during the year	0	0	0	2,020	0	0	2,020
Reclassification adjustment	0	0	0	45	0	0	45
Dividends declared	0	0	(3,720)	0	0	0	(3,720)
Dividends to non-controlling interests	0	0	0	0	0	(449)	(449)
Employee benefit transactions	9	1,231	0	0	0	0	1,240
Income tax benefit arising from employee stock option plans	0	189	0	0	0	0	189
Stock-based compensation	0	3,559	0	0	0	0	3,559
Purchase of common stock for treasury	0	0	0	0	(29,992)	0	(29,992)
Balance at Dec. 31, 2010	4,659	321,473	899,211	(3,590)	(466,230)	27,172	782,695
Net income (loss)	0	0	67,521	0	0	2,733	70,254
Sale of 50% Interest	0	0	0	0	0	(820)	820
Currency translation adjustment	0	0	0	(16,687)	0	(878)	(17,565)
Unamortized gains (losses) and prior service cost	0	0	0	(25,630)	0	0	(25,630)
Cash flow hedges:
Net derivative gains (losses) arising during the year	0	0	0	529	0	0	529
Reclassification adjustment	0	0	0	47	0	0	47
Dividends declared			(3,602)				(3,602)
Dividends to non-controlling interests	0	0	0	0	0	(1,799)	(1,799)
Employee benefit transactions	16	5,895	0	0	0	0	5,911
Income tax benefit arising from employee stock option plans	0	172	0	0	0	0	172
Stock-based compensation	0	5,832	0	0	0	0	5,832
Purchase of common stock for treasury	0	0	0	0	(48,004)	0	(48,004)
Balance at Dec. 31, 2011	4,675	333,372	963,130	(45,331)	(514,234)	26,408	768,020
Net income (loss)	0	0	74,147	0	0	2,122	76,269
Sale of 50% Interest							0
Currency translation adjustment	0	0	0	2,056	0	(577)	1,479
Unamortized gains (losses) and prior service cost	0	0	0	(7,730)	0	0	(7,730)
Cash flow hedges:
Net derivative gains (losses) arising during the year	0	0	0	(204)	0	0	(204)
Reclassification adjustment	0	0	0	11	0	0	11
Dividends declared	0	0	(4,408)	0	0		(4,408)
Capital contributions by non-controlling interest	0	0	0	0	0	808	808
Dividends to non-controlling interests	0	0	0	0	0	(5,453)	(5,453)
Employee benefit transactions	25	8,148	0	0	0	0	8,173
Income tax benefit arising from employee stock option plans	0	826	0	0	0	0	826
Stock-based compensation	0	3,583	0	0	0	0	3,583
Purchase of common stock for treasury	0	0	0	0	(27,655)	0	(27,655)
Balance at Dec. 31, 2012	$ 4,700	$ 345,929	$ 1,032,869	$ (51,198)	$ (541,889)	$ 23,308	$ 813,719