Note 3 - Contracts With Customers 2 (Details Textual) - Long-Term Contract with Customer [Member]	Jun. 30, 2022 USD ($)
Revenue, Remaining Performance Obligation, Amount	$ 2,700,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Revenue, Remaining Performance Obligation, Amount	$ 1,100,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Amount	$ 1,000,000.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Amount	$ 621,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Amount	$ 15,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year