Amortized cost, net unrealized gains or losses, and fair values (Details)	Jan. 31, 2023 USD ($)
Available For Sale Securities Amortized Cost [Member]
Asset-backed securities	$ 924,509
Corporate bonds	20,951,812
Total	21,876,321
Available For Sale Securities Fair Value [Member]
Asset-backed securities	910,291
Corporate bonds	19,819,742
Total	$ 20,730,033

Investments in notes or bonds that are collateralized by a specific group of underlying assets owned by the issuer of the notes or bonds which are short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

No definition available.

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