Restructuring Plans - (Additional Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	15 Months Ended
	Jul. 05, 2020	Jun. 30, 2019	Sep. 30, 2019	Jul. 05, 2020	Jun. 30, 2020	Mar. 31, 2020
Restructuring Cost and Reserve [Line Items]
Expected remaining cost	$ 6,500			$ 6,500
Restructuring charges	1,387	$ 2,372
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,403
Restructuring costs incurred	1,291
Energy Systems
Restructuring Cost and Reserve [Line Items]
Restructuring charges	512	1,110
Energy Systems | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges	507
Motive Power
Restructuring Cost and Reserve [Line Items]
Restructuring charges	762	558
Motive Power | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges	762
Specialty
Restructuring Cost and Reserve [Line Items]
Restructuring charges	113	704
Specialty | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges	134
Closure Of Facility In Targovishte Bulgaria
Restructuring Cost and Reserve [Line Items]
Expected remaining cost						$ 30,000
Restructuring charges			$ 20,242
Richmond Kentucky Battery Formation Area Fire
Restructuring Cost and Reserve [Line Items]
Restructuring charges	9,274	17,037			$ 26,311
Expected additional restructuring charges	50,000			50,000
Prepaid Insurance	10,000			10,000		$ 12,000
Restructuring costs incurred	$ 3,700	$ 5,000		$ 8,700	$ 22,000