Note 2 - Summary of Significant Accounting Policies - Self-Insurance (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Self-Insurance
Estimated aggregate liability for uninsured claims	$ 1.2	$ 1.7
Estimated aggregate liability for uninsured claims included in other long-term liabilities	$ 1.0	$ 0.9

The amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (cc)
-URI http://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant