Note 12 - Revenue (Details Textual 1) $ in Millions	Sep. 30, 2019 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-10-01
Disaggregation Of Revenue [Line Items]
Unrecognized revenue from unsatisfied performance obligations	$ 70
Unsatisfied performance obligations, expected to be recognized	10.00%
Unsatisfied performance obligations, expected timing of satisfaction	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Disaggregation Of Revenue [Line Items]
Unsatisfied performance obligations, expected to be recognized	30.00%
Unsatisfied performance obligations, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Disaggregation Of Revenue [Line Items]
Unsatisfied performance obligations, expected to be recognized	20.00%
Unsatisfied performance obligations, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Disaggregation Of Revenue [Line Items]
Unsatisfied performance obligations, expected to be recognized	10.00%
Unsatisfied performance obligations, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Disaggregation Of Revenue [Line Items]
Unsatisfied performance obligations, expected to be recognized	10.00%
Unsatisfied performance obligations, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Disaggregation Of Revenue [Line Items]
Unsatisfied performance obligations, expected to be recognized	20.00%
Unsatisfied performance obligations, expected timing of satisfaction