Contracts with Customers (Details)	6 Months Ended
	Mar. 31, 2019 segment
Disaggregation of Revenue [Line Items]
Number of reportable segments	3
Warranty period	12 months
Period of contract	1 year
Amortization period	1 year
SiC/LED | Minimum
Disaggregation of Revenue [Line Items]
Percentage of contract price	80.00%
SiC/LED | Maximum
Disaggregation of Revenue [Line Items]
Percentage of contract price	90.00%
Equipment Sales | Minimum
Disaggregation of Revenue [Line Items]
Warranty period	12 months
Equipment Sales | Maximum
Disaggregation of Revenue [Line Items]
Warranty period	24 months