Quarterly report pursuant to Section 13 or 15(d)

Retirement Benefits - Narrative (Details)

v3.8.0.1
Retirement Benefits - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Mar. 31, 2017
Mar. 31, 2018
Mar. 31, 2017
Retirement Benefits [Abstract]          
Pension Contributions   $ 80.0      
Postemployment Benefits, Period Expense $ 0.1   $ 0.1 $ 0.1 $ 0.2
Defined Contribution Plan, Cost $ 2.9   $ 3.1 $ 5.6 $ 5.7