Product Warranties (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Sep. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016
Product Warranties [Abstract]
Balance at beginning of period	$ 431,000		$ 431,000		$ 431,000	$ 431,000	$ 650,000	$ 650,000	$ 650,000
Provision for warranties	68,000	$ 107,000	221,000	$ 323,000
Expenses incurred	$ (68,000)	$ (107,000)	$ (221,000)	$ (323,000)