Property, Plant and Equipment (Details) $ in Thousands		12 Months Ended
	Jun. 19, 2018 USD ($) a	Dec. 31, 2020 USD ($) a	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Property, Plant and Equipment
Gross property, plant, and equipment		$ 168,638	$ 159,304
Less: accumulated depreciation and amortization, including accumulated amortization of finance leases		(106,553)	(98,869)
Property, plant, and equipment - net		62,085	60,435
Depreciation		7,850	7,944	$ 8,066
Proceeds from the sale of property, plant, and equipment		16	930	2,309
Land in Willis, TX | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Tubular and Energy Services
Property, Plant and Equipment
Proceeds from the sale of property, plant, and equipment	$ 2,047
Area of land (in acres) | a	54.5
Ball Winch Field Service | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Tubular and Energy Services
Property, Plant and Equipment
Loss on sale of land				$ 269
Land
Property, Plant and Equipment
Gross property, plant, and equipment		$ 6,627	6,612
Area of land (in acres) | a		54.5
Improvements to land and leaseholds
Property, Plant and Equipment
Gross property, plant, and equipment		$ 17,573	17,172
Buildings
Property, Plant and Equipment
Gross property, plant, and equipment		27,348	25,370
Machinery and equipment, including equipment under finance leases
Property, Plant and Equipment
Gross property, plant, and equipment		116,175	106,372
Construction in progress
Property, Plant and Equipment
Gross property, plant, and equipment		915	$ 3,778
Land and Building
Property, Plant and Equipment
Proceeds from the sale of property, plant, and equipment		900
Gain on sale of property		$ 198