Note 11 - Fair Value of Financial Instruments (Details Textual) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Variable Interest Rate [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt instrument, fair value	$ 106,200,000	$ 101,900,000
Fixed Interest Rate [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt instrument, fair value	52,400,000	21,600,000
Debt instrument, estimated fair value	52,200,000	21,100,000
Interest Rate Swap [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of interest rate swap liability	500,000	700,000
Maximum [Member] | Interest Rate Cap [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of interest rate cap assets	$ 100,000	$ 100,000