v3.26.1
REVENUE (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disaggregation of Revenue [Line Items]    
Total $ 215,056 $ 198,655
Non-Destructive Evaluation and Testing Services    
Disaggregation of Revenue [Line Items]    
Total 104,076 94,644
Repair and Maintenance Services    
Disaggregation of Revenue [Line Items]    
Total 90,435 83,882
Heat-Treating    
Disaggregation of Revenue [Line Items]    
Total 16,672 16,563
Other    
Disaggregation of Revenue [Line Items]    
Total 3,873 3,566
IHT    
Disaggregation of Revenue [Line Items]    
Total 123,391 113,621
IHT | Non-Destructive Evaluation and Testing Services    
Disaggregation of Revenue [Line Items]    
Total 104,076 94,644
IHT | Repair and Maintenance Services    
Disaggregation of Revenue [Line Items]    
Total 8 1
IHT | Heat-Treating    
Disaggregation of Revenue [Line Items]    
Total 16,653 16,374
IHT | Other    
Disaggregation of Revenue [Line Items]    
Total 2,654 2,602
MS    
Disaggregation of Revenue [Line Items]    
Total 91,665 85,034
MS | Non-Destructive Evaluation and Testing Services    
Disaggregation of Revenue [Line Items]    
Total 0 0
MS | Repair and Maintenance Services    
Disaggregation of Revenue [Line Items]    
Total 90,427 83,881
MS | Heat-Treating    
Disaggregation of Revenue [Line Items]    
Total 19 189
MS | Other    
Disaggregation of Revenue [Line Items]    
Total 1,219 964
United States    
Disaggregation of Revenue [Line Items]    
Total 166,323 157,374
United States | IHT    
Disaggregation of Revenue [Line Items]    
Total 110,342 103,803
United States | MS    
Disaggregation of Revenue [Line Items]    
Total 55,981 53,571
Canada    
Disaggregation of Revenue [Line Items]    
Total 16,557 12,207
Canada | IHT    
Disaggregation of Revenue [Line Items]    
Total 9,267 7,112
Canada | MS    
Disaggregation of Revenue [Line Items]    
Total 7,290 5,095
Other Countries    
Disaggregation of Revenue [Line Items]    
Total 32,176 29,074
Other Countries | IHT    
Disaggregation of Revenue [Line Items]    
Total 3,782 2,706
Other Countries | MS    
Disaggregation of Revenue [Line Items]    
Total $ 28,394 $ 26,368