Segment Reporting and Geographic Information (Details 2) - USD ($) $ in Thousands	Mar. 31, 2019	Sep. 30, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	$ 89,022	$ 103,542
UK
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	51,165	60,037
Greece [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	30,370	36,175
Italy [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	2,739	3,368
Rest of World [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	$ 4,748	$ 3,962