Consolidated Statements Of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2015	$ 338,146	$ 6,552	$ (21,138)	$ 120,126	$ 250,980	$ (18,374)
Beginning balance (in shares) at Dec. 31, 2015		21,837,000	(547,000)
Net loss	(12,676)				(12,676)
Foreign currency translation adjustment, net of tax	(2,498)					(2,498)
Foreign currency hedge, net of tax	300					300
Defined benefit pension plans, net of tax	(8,428)					(8,428)
Non-cash compensation	7,313			7,313
Vesting of stock awards (in shares)		142,000
Vesting of stock awards	(1,709)	$ 40		(1,749)
Tax effect of share-based payment arrangements	(535)			(535)
Issuance of common stock in Furmanite acquisition and conversion of Furmanite share-based awards (in shares)		8,208,000
Issuance of common stock in Furmanite acquisition and conversion of Furmanite share-based awards	211,530	$ 2,462		209,068
Exercise of stock options (in shares)		251,000
Exercise of stock options	$ 5,903	$ 75		5,828
Issuance of common stock, in shares	167,931	168,000
Issuance of common stock	$ 5,934	$ 50		5,884
Purchase of treasury stock (in shares)			(274,000)
Purchase of treasury stock	$ (7,593)		$ (7,593)
Retirement of treasury stock, in shares	821,087	(821,000)	821,000
Retirement of treasury stock	$ 0	$ (245)	$ 28,731	(9,129)	(19,357)
Other	(50)			(50)
Ending balance at Dec. 31, 2016	535,637	$ 8,934	$ 0	336,756	218,947	(29,000)
Ending balance (in shares) at Dec. 31, 2016		29,785,000	0
Adoption of new accounting principles	994				994
Net loss	(84,455)				(84,455)
Foreign currency translation adjustment, net of tax	7,688					7,688
Foreign currency hedge, net of tax	(1,114)					(1,114)
Defined benefit pension plans, net of tax	2,630					2,630
Issuance of convertible debt, net of tax	8,415			8,415
Non-cash compensation	7,876			7,876
Vesting of stock awards (in shares)		152,000
Vesting of stock awards	(947)	$ 45		(992)
Exercise of stock options (in shares)		16,000
Exercise of stock options	450	$ 5		445
Ending balance at Dec. 31, 2017	477,174	$ 8,984	$ 0	352,500	135,486	(19,796)
Ending balance (in shares) at Dec. 31, 2017		29,953,000	0
Adoption of new accounting principles	6,780				9,110	(2,330)
Net loss	(63,146)				(63,146)
Foreign currency translation adjustment, net of tax	(12,164)					(12,164)
Foreign currency hedge, net of tax	496					496
Defined benefit pension plans, net of tax	(598)					(598)
Reclassification of convertible debt embedded derivative, net of tax	37,698			37,698
Non-cash compensation	12,256			12,256
Vesting of stock awards (in shares)		231,000
Vesting of stock awards	$ (1,396)	$ 69		(1,465)
Exercise of stock options (in shares)	0
Ending balance at Dec. 31, 2018	$ 457,100	$ 9,053	$ 0	$ 400,989	$ 81,450	$ (34,392)
Ending balance (in shares) at Dec. 31, 2018		30,184,000	0