Retirement Benefits (Narrative) (Details) - USD ($) $ in Millions			3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 03, 2017	Oct. 01, 2016	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Pension settlement loss			$ 4.1	$ 2.0	$ 4.1	$ 2.0
Decrease in underfunded status of pension plan due to transfer to spin-off company		$ 24.0
Effect on accumulated other comprehensive loss related to transfer of defined benefit plan assets and obligations		$ 5.0
Decrease in underfunded status of pension plan due to sale of business	$ 7.0
Company contributions					40.8	$ 60.2	$ 79.3
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total expected contributions for current fiscal year					65.0
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Total expected contributions for current fiscal year					85.0
Materials Technologies [Member]
Defined Benefit Plan Disclosure [Line Items]
Periodic benefit costs including settlement, curtailment, termination benefits, and other costs			$ 3.5		$ 6.0