Quarterly report pursuant to Section 13 or 15(d)

Retirement Benefits - Narrative (Details)

v3.21.2
Retirement Benefits - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Defined Benefit Plan Disclosure [Line Items]        
Defined Contribution Plan, Cost $ 3.6 $ 3.7 $ 10.9 $ 10.8