Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Schedule of financial assets and liabilities (Details)

v3.22.2
Fair Value Measurements - Schedule of financial assets and liabilities (Details) - USD ($)
$ in Millions
Jun. 30, 2022
Sep. 30, 2021
Assets:    
Cash and cash equivalents $ 284.4 $ 446.1
Restricted Cash 1.1 1.3
Cash and cash equivalents   3.5
Investments in rabbi trust 3.8 4.2
Derivative instruments 2.5 1.9
Liabilities:    
Derivative instruments 5.8 2.5
TerraSource Global    
Assets:    
Cash and cash equivalents   3.5
Cash flow hedging | Foreign Exchange Forward    
Liabilities:    
Derivative, notional amount 193.4 186.4
Level 1    
Assets:    
Cash and cash equivalents 284.4 446.1
Restricted Cash 1.1 1.3
Cash and cash equivalents   3.5
Investments in rabbi trust 3.8 4.2
Derivative instruments 0.0 0.0
Liabilities:    
Derivative instruments 0.0 0.0
Level 2    
Assets:    
Cash and cash equivalents 0.0 0.0
Restricted Cash 0.0 0.0
Cash and cash equivalents   0.0
Investments in rabbi trust 0.0 0.0
Derivative instruments 2.5 1.9
Liabilities:    
Derivative instruments 5.8 2.5
Level 3    
Assets:    
Cash and cash equivalents 0.0 0.0
Restricted Cash 0.0 0.0
Cash and cash equivalents   0.0
Investments in rabbi trust 0.0 0.0
Derivative instruments 0.0 0.0
Liabilities:    
Derivative instruments 0.0 0.0
2021 Notes    
Liabilities:    
Debt instruments 350.0 350.0
2021 Notes | Level 1    
Liabilities:    
Debt instruments 289.8 349.0
2021 Notes | Level 2    
Liabilities:    
Debt instruments 0.0 0.0
2021 Notes | Level 3    
Liabilities:    
Debt instruments 0.0 0.0
2020 Notes    
Liabilities:    
Debt instruments 400.0 400.0
2020 Notes | Level 1    
Liabilities:    
Debt instruments 408.4 422.8
2020 Notes | Level 2    
Liabilities:    
Debt instruments 0.0 0.0
2020 Notes | Level 3    
Liabilities:    
Debt instruments 0.0 0.0
2019 Notes    
Liabilities:    
Debt instruments 374.6 374.6
2019 Notes | Level 1    
Liabilities:    
Debt instruments 357.1 421.3
2019 Notes | Level 2    
Liabilities:    
Debt instruments 0.0 0.0
2019 Notes | Level 3    
Liabilities:    
Debt instruments 0.0 0.0
Series A Notes    
Liabilities:    
Debt instruments 100.0 100.0
Series A Notes | Level 1    
Liabilities:    
Debt instruments 0.0 0.0
Series A Notes | Level 2    
Liabilities:    
Debt instruments 97.4 107.6
Series A Notes | Level 3    
Liabilities:    
Debt instruments $ 0.0 $ 0.0