v3.26.1
Fair Value Measurements - Schedule of Assets and Liabilities at Fair Value (Details) - Fair Value, Measurements, Recurring - USD ($)
$ in Millions
Jun. 30, 2026
Sep. 30, 2025
Other noncurrent assets    
Non-qualified trust funds $ 3.5 $ 2.2
Deferred compensation investments 21.2 19.2
Total assets at fair value 29.5 24.8
Other noncurrent liabilities    
Deferred compensation obligations 21.9 20.4
Total liabilities at fair value 21.9 20.4
Money market funds    
Cash and cash equivalents    
Cash and cash equivalents 2.1 0.8
Time deposits    
Cash and cash equivalents    
Cash and cash equivalents 2.7 2.6
Level 1    
Other noncurrent assets    
Non-qualified trust funds 0.0 0.0
Deferred compensation investments 21.2 19.2
Total assets at fair value 23.3 20.0
Other noncurrent liabilities    
Deferred compensation obligations 0.0 0.0
Total liabilities at fair value 0.0 0.0
Level 1 | Money market funds    
Cash and cash equivalents    
Cash and cash equivalents 2.1 0.8
Level 1 | Time deposits    
Cash and cash equivalents    
Cash and cash equivalents 0.0 0.0
Level 2    
Other noncurrent assets    
Non-qualified trust funds 0.0 0.0
Deferred compensation investments 0.0 0.0
Total assets at fair value 2.7 2.6
Other noncurrent liabilities    
Deferred compensation obligations 0.0 0.0
Total liabilities at fair value 0.0 0.0
Level 2 | Money market funds    
Cash and cash equivalents    
Cash and cash equivalents 0.0 0.0
Level 2 | Time deposits    
Cash and cash equivalents    
Cash and cash equivalents 2.7 2.6
Level 3    
Other noncurrent assets    
Non-qualified trust funds 0.0 0.0
Deferred compensation investments 0.0 0.0
Total assets at fair value 0.0 0.0
Other noncurrent liabilities    
Deferred compensation obligations 0.0 0.0
Total liabilities at fair value 0.0 0.0
Level 3 | Money market funds    
Cash and cash equivalents    
Cash and cash equivalents 0.0 0.0
Level 3 | Time deposits    
Cash and cash equivalents    
Cash and cash equivalents 0.0 0.0
NAV    
Other noncurrent assets    
Non-qualified trust funds 3.5 2.2
Total assets at fair value 3.5 2.2
Other noncurrent liabilities    
Deferred compensation obligations 21.9 20.4
Total liabilities at fair value $ 21.9 $ 20.4