Note 13 - Long-term Debt and Credit Arrangements - Schedule of Long-term Debt (Details) (Parentheticals) - The 2.75% Convertible Notes [Member]	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Interest rate	2.75%	2.75%	2.75%
Convertible Debt [Member]
Interest rate	2.75%	2.75%	2.75%

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant