Segment Information (Narrative) (Details) $ in Millions	12 Months Ended
	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reporting segments | segment	4
Non-recurring HRG operating costs	$ 18.9	$ 31.9	$ 72.5
HRG [Member] | One-Time Termination Pension Plan [Member]
Segment Reporting Information [Line Items]
Non-recurring HRG operating costs	1.2
HRG [Member] | One-Time Termination Lease [Member]
Segment Reporting Information [Line Items]
Non-recurring HRG operating costs	$ 3.1