Revenue (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Deferred Revenue, Revenue Recognized	$ 0.3	$ 0.4	$ 0.6	$ 3.3
Capitalized Contract Cost, Net	9.2		$ 9.2		$ 9.4
capitalized contract costs amortization period			25 years
Capitalized Contract Cost, Amortization	$ 0.1	$ 0.1	$ 0.2	$ 0.2