Note 16 - Commitments and Contingencies (Details Textual)	6 Months Ended
Jan. 31, 2020 USD ($)
Salary and Wage, Officer, Excluding Cost of Good and Service Sold	$ 704,000

Amount of expense for salary and wage arising from service rendered by officer. Excludes allocated cost, labor-related nonsalary expense, and direct and overhead labor cost included in cost of good and service sold.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(4))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Name:	us-gaap_OfficersCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration