Note 11 - Product Warranty Obligations - Recognition of Deferred Revenue Related to Extended Warranties 2 (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Revenue performance obligation	$ 78,738
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue performance obligation	15,535
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue performance obligation	16,798
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue performance obligation	14,705
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue performance obligation	11,367
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue performance obligation	$ 20,333