Condensed Consolidated Statements Of Equity - USD ($) shares in Thousands, $ in Thousands	Common Shares in Treasury [Member]	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Non-controlling Interests [Member]	Total
Beginning Balances at Dec. 31, 2018	$ (165,545)	$ 93,436	$ 298,123	$ 255,978	$ (105,361)	$ 9,218	$ 385,849
Beginning Balances, shares at Dec. 31, 2018	10,433
Net income (loss)				13,604		274	13,878
Other comprehensive income (loss)					(912)	106	(806)
Purchase of treasury stock	$ (25,000)						(25,000)
Purchase of treasury stock, shares	1,441
Stock-based compensation transactions	$ 8,422		(6,446)				1,976
Stock-based compensation transactions, shares	(370)
Ending Balances at Mar. 31, 2019	$ (182,123)	93,436	291,677	269,582	(106,273)	9,598	375,897
Ending Balances, shares at Mar. 31, 2019	11,504
Beginning Balances at Dec. 31, 2018	$ (165,545)	93,436	298,123	255,978	(105,361)	9,218	385,849
Beginning Balances, shares at Dec. 31, 2018	10,433
Net income (loss)							38,197
Other comprehensive income (loss)							(16,892)
Ending Balances at Sep. 30, 2019	$ (181,094)	93,436	293,970	293,273	(121,999)	9,212	386,798
Ending Balances, shares at Sep. 30, 2019	11,467
Beginning Balances at Mar. 31, 2019	$ (182,123)	93,436	291,677	269,582	(106,273)	9,598	375,897
Beginning Balances, shares at Mar. 31, 2019	11,504
Net income (loss)				10,871		238	11,109
Other comprehensive income (loss)					(3,360)	(116)	(3,476)
Stock-based compensation transactions	$ 37		2,181				2,218
Stock-based compensation transactions, shares	(1)
Distributions to noncontrolling interests						(654)	(654)
Ending Balances at Jun. 30, 2019	$ (182,086)	93,436	293,858	280,453	(109,633)	9,066	385,094
Ending Balances, shares at Jun. 30, 2019	11,503
Net income (loss)				12,820		390	13,210
Other comprehensive income (loss)					(12,366)	(244)	(12,610)
Stock-based compensation transactions	$ 992		112				1,104
Stock-based compensation transactions, shares	(36)
Ending Balances at Sep. 30, 2019	$ (181,094)	93,436	293,970	293,273	(121,999)	9,212	386,798
Ending Balances, shares at Sep. 30, 2019	11,467
Beginning Balances at Dec. 31, 2019	$ (180,243)	93,436	294,543	262,016	(109,376)	9,826	370,202
Beginning Balances, shares at Dec. 31, 2019	11,431
Net income (loss)				16,123		10	16,133
Other comprehensive income (loss)					(27,312)	(94)	(27,406)
Stock-based compensation transactions	$ 5,332		(2,723)				2,609
Stock-based compensation transactions, shares	(238)
Ending Balances at Mar. 31, 2020	$ (174,911)	93,436	291,820	278,139	(136,688)	9,742	361,538
Ending Balances, shares at Mar. 31, 2020	11,193
Beginning Balances at Dec. 31, 2019	$ (180,243)	93,436	294,543	262,016	(109,376)	9,826	370,202
Beginning Balances, shares at Dec. 31, 2019	11,431
Net income (loss)							25,883
Other comprehensive income (loss)							(11,009)
Ending Balances at Sep. 30, 2020	$ (173,945)	93,436	294,077	287,073	(120,012)	10,279	390,908
Ending Balances, shares at Sep. 30, 2020	11,145
Beginning Balances at Mar. 31, 2020	$ (174,911)	93,436	291,820	278,139	(136,688)	9,742	361,538
Beginning Balances, shares at Mar. 31, 2020	11,193
Net income (loss)				(5,540)		376	(5,164)
Other comprehensive income (loss)					2,333	(36)	2,297
Stock-based compensation transactions	$ 159		1,825				1,984
Stock-based compensation transactions, shares	(8)
Ending Balances at Jun. 30, 2020	$ (174,752)	93,436	293,645	272,599	(134,355)	10,082	360,655
Ending Balances, shares at Jun. 30, 2020	11,185
Net income (loss)				14,474		440	14,914
Other comprehensive income (loss)					14,343	(243)	14,100
Stock-based compensation transactions	$ 807		432				1,239
Stock-based compensation transactions, shares	(40)
Ending Balances at Sep. 30, 2020	$ (173,945)	$ 93,436	$ 294,077	$ 287,073	$ (120,012)	$ 10,279	$ 390,908
Ending Balances, shares at Sep. 30, 2020	11,145