Industry Segments and Geographic Information - Geographic Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	$ 388,272	$ 377,715	$ 561,241
Total identifiable assets	398,266	1,132,839
Geography Eliminations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	(195)	(848)	(1,802)
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	388,272	377,715	561,241
Operating Segments | Discontinued operations
Revenues from External Customers and Long-Lived Assets [Line Items]
Total identifiable assets	0	710,006
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	251,786	225,835	411,284
United States | Reportable Geographical Components
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	251,786	225,835	411,284
Total identifiable assets	291,986	285,765
Canada and Mexico | Reportable Geographical Components
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	5,363	1,347	6,616
Total identifiable assets	5,891	6,452
South America | Reportable Geographical Components
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	10,473	11,583	13,188
Total identifiable assets	21,837	10,388
Europe | Reportable Geographical Components
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	88,136	90,303	93,327
Total identifiable assets	72,685	85,733
Europe | Geography Eliminations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	195	848	1,802
Africa | Reportable Geographical Components
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	2,262	8,128	16,874
Total identifiable assets	199	9,195
Middle East, Asia and other | Reportable Geographical Components
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	30,252	40,519	$ 19,952
Total identifiable assets	$ 5,668	$ 25,300