v3.26.1
Accumulated Other Comprehensive Loss - Components of and Changes in Accumulated Other Comprehensive (Loss) Income (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2026
Mar. 31, 2025
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance $ 1,357,657 $ 1,260,101 $ 1,324,648 $ 1,288,599
Ending Balance 1,398,372 1,278,916 1,398,372 1,278,916
Pension and other postretirement benefits attributable to Kennametal        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance     (223,016) (221,308)
Other comprehensive income (loss) before reclassifications     1,393 (887)
Amounts reclassified from AOCL     6,684 5,277
Net other comprehensive income (loss)     8,077 4,390
Ending Balance (214,939) (216,918) (214,939) (216,918)
Currency translation adjustment attributable to Kennametal        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance     (165,859) (216,263)
Other comprehensive income (loss) before reclassifications     (14,559) 1,329
Amounts reclassified from AOCL     0 0
Net other comprehensive income (loss)     (14,559) 1,329
Ending Balance (180,418) (214,934) (180,418) (214,934)
Derivatives attributable to noncontrolling interests        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance     2,182 2,983
Other comprehensive income (loss) before reclassifications     (197) 827
Amounts reclassified from AOCL     (366) (1,160)
Net other comprehensive income (loss)     (563) (333)
Ending Balance 1,619 2,650 1,619 2,650
Total attributable to Kennametal        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance (381,614) (450,460) (386,693) (434,588)
Other comprehensive income (loss) before reclassifications     (13,363) 1,269
Amounts reclassified from AOCL     6,318 4,117
Net other comprehensive income (loss)     (7,045) 5,386
Ending Balance (393,738) (429,202) (393,738) (429,202)
Pension and other postretirement benefits attributable to noncontrolling interests        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance     0 0
Other comprehensive income (loss) before reclassifications     0 0
Net other comprehensive income (loss)     0 0
Ending Balance 0 0 0 0
Currency translation adjustment attributable to noncontrolling interests        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance     (7,844) (8,680)
Other comprehensive income (loss) before reclassifications     (2,259) (409)
Net other comprehensive income (loss)     (2,259) (409)
Ending Balance (10,103) (9,089) (10,103) (9,089)
Derivatives attributable to noncontrolling interests        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance     0 0
Other comprehensive income (loss) before reclassifications     0 0
Net other comprehensive income (loss)     0 0
Ending Balance 0 0 0 0
Total attributable to noncontrolling interests        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance     (7,844) (8,680)
Other comprehensive income (loss) before reclassifications     (2,259) (409)
Net other comprehensive income (loss)     (2,259) (409)
Ending Balance (10,103) (9,089) (10,103) (9,089)
Noncontrolling Interest        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Beginning Balance 42,620 40,121 40,669 38,724
Ending Balance 43,638 42,048 43,638 42,048
Reclassification out of Accumulated Other Comprehensive Loss | Pension and other postretirement benefits attributable to Kennametal        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest (2,892) (2,052) (8,658) (7,036)
Reclassification out of Accumulated Other Comprehensive Loss | Derivatives attributable to noncontrolling interests        
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]        
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest $ (237) $ (1,017) $ (485) $ (1,536)