Geographical Information (Schedule of Revenue by Geographic Region) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Revenue	$ 29,176	$ 30,952	$ 32,591	$ 30,176	$ 25,600	$ 22,376	$ 21,532	$ 22,490	$ 122,895	$ 91,998	$ 81,685
United States [Member]
Segment Reporting Information [Line Items]
Revenue									98,520	66,436	55,736
Asia [Member]
Segment Reporting Information [Line Items]
Revenue									16,713	17,401	16,885
Europe [Member]
Segment Reporting Information [Line Items]
Revenue									7,015	7,618	8,249
Other [Member]
Segment Reporting Information [Line Items]
Revenue									$ 647	$ 543	$ 815