Segment Reporting and Geographic Information (Details 2) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	$ 151.2	$ 92.7	$ 103.5
UK [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	116.1	52.8	60.0
Greece [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	26.5	32.8	36.2
Italy [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	2.3	3.0	3.4
Rest of world [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total non-current assets excluding goodwill	$ 6.3	$ 4.1	$ 3.9