Note 2 - Revenue From Contracts With Customers - Disaggregation of Revenue (Details)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Percent of revenues	100.00%	100.00%
Transferred over Time [Member]
Percent of revenues	58.00%	75.00%
Transferred at Point in Time [Member]
Percent of revenues	42.00%	25.00%