v3.26.1
Review of Operations by Segment (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Segment Reporting [Abstract]          
Number of reportable segments disclosed by definition flag     Total Reportable Segments    
Operations by segment          
Total revenues $ 187,342 $ 315,972 $ 511,390 $ 629,025  
Selling, general and administrative expenses 49,062 53,773 101,430 105,844  
Property, plant and equipment impairment charge 0 7,386 0 7,386  
Other segment activities (37,084) (639) 38,670 5,139  
Operating income (loss) from continuing operations (244,423) (31,583) (250,308) (26,535)  
Interest income 580 414 1,038 868  
Interest expense (8,239) (8,739) (16,766) (17,445)  
Facility fees and debt-related income (expense) (318) (154) (538) (570)  
Defined benefit pension income (expense) (3,918) (5,555) (7,854) (10,756)  
Income (loss) from continuing operations before income taxes and equity in income (256,318) (45,617) (274,428) (54,438)  
Depreciation     76,838 74,343  
Amortization     13,653 14,964  
Capital expenditures 22,318 26,895 41,622 41,867  
Total assets 1,722,786   1,722,786   $ 2,742,789
Continuing Operations          
Operations by segment          
Depreciation 28,854 28,352 58,179 55,174  
Amortization 1,865 1,635 3,771 3,193  
Service and Product          
Operations by segment          
Cost of services and products sold 345,619 285,757 621,598 537,191  
Operating Segments          
Operations by segment          
Total revenues 187,342 315,972 511,390 629,025  
Selling, general and administrative expenses 37,526 36,817 77,227 75,027  
Property, plant and equipment impairment charge   7,386   7,386  
Other segment activities (12,067) (2,086) 13,603 8,284  
Operating income (loss) from continuing operations (207,870) (16,074) (201,038) 1,137  
Capital expenditures 22,227 26,887 41,402 41,761  
Operating Segments | Continuing Operations          
Operations by segment          
Depreciation 28,623 28,097 57,715 54,638  
Amortization 813 677 1,670 1,284  
Operating Segments | Service and Product          
Operations by segment          
Cost of services and products sold 345,619 285,757 621,598 537,191  
Operating Segments | Harsco Environmental          
Operations by segment          
Total revenues 266,160 258,009 522,877 501,115  
Selling, general and administrative expenses 27,196 25,494 55,139 52,122  
Property, plant and equipment impairment charge   7,386   7,386  
Other segment activities (4,048) (684) 4,786 5,072  
Operating income (loss) from continuing operations 12,976 4,251 23,005 14,324  
Capital expenditures 20,704 25,257 38,111 39,351  
Operating Segments | Harsco Environmental | Continuing Operations          
Operations by segment          
Depreciation 27,438 27,046 55,334 52,555  
Amortization 568 571 1,140 1,111  
Operating Segments | Harsco Environmental | Service and Product          
Operations by segment          
Cost of services and products sold 221,940 220,194 439,947 422,211  
Operating Segments | Harsco Rail          
Operations by segment          
Total revenues (78,818) 57,963 (11,487) 127,910  
Selling, general and administrative expenses 10,330 11,323 22,088 22,905  
Property, plant and equipment impairment charge   0   0  
Other segment activities (8,019) (1,402) 8,817 3,212  
Operating income (loss) from continuing operations (220,846) (20,325) (224,043) (13,187)  
Capital expenditures 1,523 1,630 3,291 2,410  
Operating Segments | Harsco Rail | Continuing Operations          
Operations by segment          
Depreciation 1,185 1,051 2,381 2,083  
Amortization 245 106 530 173  
Operating Segments | Harsco Rail | Service and Product          
Operations by segment          
Cost of services and products sold 123,679 65,563 181,651 114,980  
Corporate          
Operations by segment          
Total revenues 0 0 0 0  
Selling, general and administrative expenses 11,536 16,956 24,203 30,817  
Property, plant and equipment impairment charge   0   0  
Other segment activities (25,017) 1,447 25,067 (3,145)  
Operating income (loss) from continuing operations (36,553) (15,509) (49,270) (27,672)  
Capital expenditures 91 8 220 106  
Corporate | Continuing Operations          
Operations by segment          
Depreciation 231 255 464 536  
Amortization 1,052 958 2,101 1,909  
Corporate | Service and Product          
Operations by segment          
Cost of services and products sold $ 0 $ 0 $ 0 $ 0