Consolidated Statements of Equity - USD ($) $ in Thousands	Common Stock [Member] Restricted Stock Units (RSUs) [Member]	Common Stock [Member] Performance Shares [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]	Restricted Stock Units (RSUs) [Member]	Performance Shares [Member]	Total
Balance (in shares) at Dec. 31, 2016			33,956,304
Issuance of common stock upon stock option exercises (in shares)			43,573							43,573
Issuance of shares pursuant to restricted stock units (in shares)	95,510	49,672
Issuance of shares pursuant to deferred stock units (in shares)			30,559
Forfeitures of restricted shares (in shares)			(1,084)
Shares repurchased and retired (in shares)			(1,711,992)
Balance (in shares) at Dec. 31, 2017			32,462,542
Balance at Dec. 31, 2016			$ 340	$ 167,700	$ 446,095	$ (45,635)	$ 7,683			$ 576,183
Issuance of common stock upon stock option exercises			0	822						822
Issuance of shares pursuant to restricted stock units	$ 1	$ 0						$ 1	$ 0
Issuance of shares pursuant to deferred stock units			0							0
Shares repurchased and retired			(16)	(37,833)						(37,849)
Balance at Dec. 31, 2017			$ 325	140,749	376,694	(23,522)	10,810			505,056
Equity-based compensation expense				10,060						10,060
Cumulative effect adjustment (see Revenues: Note 3)					0					0
Net income (loss)					(69,401)		2,819			(66,582)
Currency translation adjustment and derivative transactions, net						22,113	221			22,334
Investments from non-controlling interest							158			158
Distributions to non-controlling interests							(71)			(71)
Sale of non-controlling interests							0			0
Investments from non-controlling interest							158			$ 158
Issuance of common stock upon stock option exercises (in shares)			0							(0)
Issuance of shares pursuant to restricted stock units (in shares)	312,182	296,909
Issuance of shares pursuant to deferred stock units (in shares)			28,308
Forfeitures of restricted shares (in shares)			0
Shares repurchased and retired (in shares)			(1,177,532)
Balance (in shares) at Dec. 31, 2018			31,922,409							31,922,409
Issuance of common stock upon stock option exercises			$ 0	0						$ 0
Issuance of shares pursuant to restricted stock units	$ 3	$ 3						3	3
Issuance of shares pursuant to deferred stock units			0							0
Shares repurchased and retired			(12)	(25,769)						(25,781)
Balance at Dec. 31, 2018			$ 319	122,818	379,890	(40,290)	7,450			470,187
Equity-based compensation expense				7,838						7,838
Cumulative effect adjustment (see Revenues: Note 3)					268					268
Net income (loss)					2,928		159			3,087
Currency translation adjustment and derivative transactions, net						(16,768)	(158)			(16,926)
Investments from non-controlling interest							0			0
Distributions to non-controlling interests							0			0
Sale of non-controlling interests							(3,361)			(3,361)
Investments from non-controlling interest							0			$ 0
Issuance of common stock upon stock option exercises (in shares)			52,783							52,783
Issuance of shares pursuant to restricted stock units (in shares)	237,416	111,158
Issuance of shares pursuant to deferred stock units (in shares)			84,184
Forfeitures of restricted shares (in shares)			0
Shares repurchased and retired (in shares)			(1,691,991)
Balance (in shares) at Dec. 31, 2019			30,715,959							30,715,959
Issuance of common stock upon stock option exercises			$ 1	955						$ 956
Issuance of shares pursuant to restricted stock units	$ 2	$ 1						$ 2	$ 1
Issuance of shares pursuant to deferred stock units			1							1
Shares repurchased and retired			(17)	(30,376)						(30,393)
Balance at Dec. 31, 2019			$ 307	101,148	358,998	(32,694)	7,334			435,093
Equity-based compensation expense				$ 7,751						7,751
Cumulative effect adjustment (see Revenues: Note 3)					0					0
Net income (loss)					$ (20,892)		1,444			(19,448)
Currency translation adjustment and derivative transactions, net						$ 7,596	49			7,645
Investments from non-controlling interest										0
Distributions to non-controlling interests							(1,609)			(1,609)
Sale of non-controlling interests							$ 0			0
Investments from non-controlling interest										$ 0