Segment, Customer and Geographical Reporting - Segment revenue (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 11,090,000	$ 10,542,000	$ 32,650,000	$ 29,985,000
% of Total	100.00%	100.00%	100.00%	100.00%
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 8,669,000	$ 7,512,000	$ 24,901,000	$ 22,993,000
% of Total	78.00%	71.00%	76.00%	76.00%
Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 667,000	$ 877,000	$ 2,462,000	$ 877,000
% of Total	6.00%	9.00%	8.00%	3.00%
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 1,468,000	$ 2,029,000	$ 4,705,000	$ 4,662,000
% of Total	13.00%	19.00%	14.00%	16.00%
Other Credit Derivatives [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 286,000	$ 124,000	$ 582,000	$ 1,453,000
% of Total	3.00%	1.00%	2.00%	5.00%