Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Financial instruments (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Recurring
Fair value, Assets	$ 0	$ 128,000
Fair Value, Inputs, Level 3 [Member]
Recurring
Fair value, Assets		128,000
Certificate of deposit
Recurring
Fair value, Assets		2,500,000
Certificate of deposit \| Fair Value, Inputs, Level 2 [Member]
Recurring
Fair value, Assets		$ 2,500,000