Note 7 - Assets Held for Sale (Details Textual) ¥ in Thousands, $ in Thousands	3 Months Ended
Jun. 30, 2023 USD ($)	Jun. 30, 2023 CNY (¥)	Jun. 30, 2022 USD ($)
Number of Equipment Held for Sale	2
Asset, Held-for-Sale, Not Part of Disposal Group, Current	$ 274	¥ 1,985	$ 0

Amount of assets held-for-sale that are not part of a disposal group, expected to be sold within a year or the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481372/852-10-55-10

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 15
-Paragraph 4
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482309/360-10-15-4

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