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, 2010	$ 4,659	$ 321,473	$ 899,211	$ (3,590)	$ (466,230)	$ 27,172	$ 782,695
Net income	0	0	67,521	0	0	2,733	70,254
Sale of controlling interest	0	0	0	0	0	(820)	(820)
Currency translation adjustment	0	0	0	(16,687)	0	(878)	(17,565)
Unamortized losses and prior service cost	0	0	0	(25,630)	0	0	(25,630)
Cash flow hedge:
Net derivative 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	0	0	74,147	0	0	2,122	76,269
Currency translation adjustment	0	0	0	2,056	0	(577)	1,479
Unamortized losses and prior service cost	0	0	0	(7,730)	0	0	(7,730)
Cash flow hedge:
Net derivative 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 interests	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
Net income	0	0	80,330	0	0	3,121	83,451
Currency translation adjustment	0	0	0	(14,860)	0	(1,673)	(16,533)
Unamortized losses and prior service cost	0	0	0	34,281	0	0	34,281
Cash flow hedge:
Net derivative losses arising during the year	0	0	0	514	0	0	514
Reclassification adjustment	0	0	0	(2)	0	0	(2)
Dividends declared	0	0	(6,946)	0	0	0	(6,946)
Dividends to non-controlling interests	0	0	0	0	0	(2,445)	(2,445)
Employee benefit transactions	56	12,052	0	0	0	0	12,108
Equity reclassification adjustment to non-controlling interests	0	(4,559)	0	0	0	4,559	0
Income tax benefit arising from employee stock option plans	0	2,788	0	0	0	0	2,788
Stock-based compensation	0	5,249	0	0	0	0	5,249
Purchase of common stock for treasury	0	0	0	0	(51,776)	0	(51,776)
Balance at Dec. 31, 2013	$ 4,756	$ 361,459	$ 1,106,253	$ (31,265)	$ (593,665)	$ 26,870	$ 874,408