Revenue Recognition - Schedule of Product and Market Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Net Sales	$ 556.4	$ 374.4	$ 1,128.3	$ 947.7
Modern Markets
Disaggregation of Revenue [Line Items]
Net Sales	102.5	83.8	229.9	213.8
Developing Markets
Disaggregation of Revenue [Line Items]
Net Sales	44.9	44.7	94.6	91.3
Distributors Markets
Disaggregation of Revenue [Line Items]
Net Sales	27.4	21.8	48.7	45.4
North America
Disaggregation of Revenue [Line Items]
Net Sales	323.9	196.6	664.9	531.6
Latin America
Disaggregation of Revenue [Line Items]
Net Sales	57.7	27.5	90.2	65.6
Americas
Disaggregation of Revenue [Line Items]
Net Sales	381.6	224.1	755.1	597.2
International
Disaggregation of Revenue [Line Items]
Net Sales	174.8	150.3	373.2	350.5
Batteries
Disaggregation of Revenue [Line Items]
Net Sales	419.4	330.3	941.3	854.8
Auto Care
Disaggregation of Revenue [Line Items]
Net Sales	108.6	23.4	129.1	44.8
Lights and Licensing
Disaggregation of Revenue [Line Items]
Net Sales	$ 28.4	$ 20.7	$ 57.9	$ 48.1