Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - 6 months ended Jun. 30, 2018 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]
Beginning Balance at Dec. 31, 2017	$ 486,104	$ 275	$ 292,494	$ 211,080	$ (17,745)
Beginning Balance, Shares at Dec. 31, 2017		27,572
Net loss	(30,494)			(30,494)
Dividends declared	(3,884)			(3,884)
Share-based compensation expense	2,334	$ 2	2,332
Share-based compensation expense, shares		165
Shares issued for option exercises	$ 274		274
Shares issued for option exercises, shares	27	27
Restricted shares and performance shares forgiven for taxes and forfeited	$ (720)		(720)
Restricted shares forgiven for taxes and forfeited, shares		(35)
Foreign currency translation gain (loss)	(10,316)				(10,316)
Adoption of new accounting standard (Note 1)	16			16
Ending Balance at Jun. 30, 2018	$ 443,314	$ 277	$ 294,380	$ 176,718	$ (28,061)
Ending Balance, Shares at Jun. 30, 2018		27,729