PATENTS, NET OF ACCUMULATED AMORTIZATION (Details Narrative) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Patents Net Of Accumulated Amortization
Accumulated amortization	$ 291,600	$ 319,900
Accrued patent acquisition costs	13,000
Accrued patent acquisition costs due within a year	8,000
Accrued patent acquisition costs due within 2 years	$ 5,000

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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