Note 6 - Deferred Service Contract Revenue (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Deferred Revenue Costs Incurred	$ 1.6	$ 1.4	$ 3.2	$ 3.1