Note 7 - Affiliates Balances - Amounts Due to Affiliate (Details) $ in Thousands	6 Months Ended
Jun. 30, 2021 USD ($)
Due to Sonatide at December 31, 2020	$ 53,194
Total due to Sonatide at June 30, 2021	59,759
Sonatide [Member]
Due to Sonatide at December 31, 2020	32,767
Plus additional commissions payable to Sonatide	1,596
Plus amounts paid by Sonatide on behalf of the company	4,331
Other	278
Total due to Sonatide at June 30, 2021	$ 38,972

Amount of payable due to an entity that is affiliated with the reporting entity by means of direct or indirect ownership. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 3: 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(19)(a)(5))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(12)(b)(3))
-URI http://asc.fasb.org/extlink&oid=120401414&loc=d3e603758-122996

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