v3.26.3
Accumulated Other Comprehensive Loss - Components of and Changes in Accumulated Other Comprehensive (Loss) Income (Details) - USD ($)
$ in Thousands
 3 Months Ended
Sep. 30, 2026
Sep. 30, 2025
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance $ 1,613,437 $ 1,324,648
Ending Balance 1,867,990 1,325,597
Pension and other postretirement benefits attributable to Kennametal    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (207,857) (223,016)
Other comprehensive (loss) income before reclassifications (154) 646
Amounts reclassified from AOCL 2,192 2,353
Net other comprehensive income (loss) 2,038 2,999
Ending Balance (205,819) (220,017)
Currency translation adjustment attributable to Kennametal    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (192,592) (165,859)
Other comprehensive (loss) income before reclassifications (4,757) (2,629)
Amounts reclassified from AOCL 0 0
Net other comprehensive income (loss) (4,757) (2,629)
Ending Balance (197,349) (168,488)
Derivatives attributable to noncontrolling interests    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance 1,419 2,182
Other comprehensive (loss) income before reclassifications 72 (8)
Amounts reclassified from AOCL (193) (166)
Net other comprehensive income (loss) (121) (174)
Ending Balance 1,298 2,008
Total attributable to Kennametal    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (399,030) (386,693)
Other comprehensive (loss) income before reclassifications (4,839) (1,991)
Amounts reclassified from AOCL 1,999 2,187
Net other comprehensive income (loss) (2,840) 196
Ending Balance (401,870) (386,497)
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 (loss) income before reclassifications 0 0
Net other comprehensive income (loss) 0 0
Ending Balance 0 0
Currency translation adjustment attributable to noncontrolling interests    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (10,085) (7,844)
Other comprehensive (loss) income before reclassifications (267) (625)
Net other comprehensive income (loss) (267) (625)
Ending Balance (10,352) (8,469)
Derivatives attributable to noncontrolling interests    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance 0 0
Other comprehensive (loss) income before reclassifications 0 0
Net other comprehensive income (loss) 0 0
Ending Balance 0 0
Total attributable to noncontrolling interests    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (10,085) (7,844)
Other comprehensive (loss) income before reclassifications (267) (625)
Net other comprehensive income (loss) (267) (625)
Ending Balance $ (10,352) $ (8,469)