Revenue Recognition - Schedule of Product and Market Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Net Sales	$ 587.0	$ 556.4	$ 1,323.8	$ 1,128.3
Modern Markets
Disaggregation of Revenue [Line Items]
Net Sales	101.1	102.5	243.9	229.9
Developing Markets
Disaggregation of Revenue [Line Items]
Net Sales	46.2	44.9	97.4	94.6
Distributors Markets
Disaggregation of Revenue [Line Items]
Net Sales	29.8	27.4	58.1	48.7
North America
Disaggregation of Revenue [Line Items]
Net Sales	360.3	323.9	814.0	664.9
Latin America
Disaggregation of Revenue [Line Items]
Net Sales	49.6	57.7	110.4	90.2
Americas
Disaggregation of Revenue [Line Items]
Net Sales	409.9	381.6	924.4	755.1
International
Disaggregation of Revenue [Line Items]
Net Sales	177.1	174.8	399.4	373.2
Batteries
Disaggregation of Revenue [Line Items]
Net Sales	427.7	419.4	1,049.6	941.3
Auto Care
Disaggregation of Revenue [Line Items]
Net Sales	130.2	108.6	208.9	129.1
Lights and Licensing
Disaggregation of Revenue [Line Items]
Net Sales	$ 29.1	$ 28.4	$ 65.3	$ 57.9