Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - 9 months ended Sep. 30, 2018 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	AOCI Attributable to Parent
Beginning Balance at Dec. 31, 2017	$ 486,104	$ 275	$ 292,494	$ 211,080	$ (17,745)
Beginning Balance, Shares at Dec. 31, 2017		27,572
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Net loss	(44,277)			(44,277)
Cash dividends declared	$ (5,835)			(5,835)
Shares issued, shares	14,375
Shares issued	$ 217,312	$ 144	217,168
Share-based compensation expense	3,425	$ 2	3,423
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	$ (723)		(723)
Change in estimate of performance share vesting	(753)		(802)	49
Restricted shares forgiven for taxes and forfeited, shares		(35)
Foreign currency translation loss	(14,509)				(14,509)
Adoption of new accounting standard (Note 1)	16			16
Ending Balance at Sep. 30, 2018	$ 641,034	$ 421	$ 511,834	$ 161,033	$ (32,254)
Ending Balance, Shares at Sep. 30, 2018		42,104