Note 2 - Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Apr. 30, 2017	Apr. 30, 2016
Promissory notes	$ 2,604	$ 3,988
Notes payable	5,644	7,682
	5,644	7,682
Less: Current maturities	2,297	2,464
	3,347	5,218
Note Payable Paid off in 2017 [Member]
Notes payable		81
		81
Debt Instrument Due December 2017 and March 2018 [Member]
Notes payable	685	1,150
	685	1,150
Other Notes Payable [Member]
Notes payable		3
		3
Note Collateralized by Real Estate [Member]
Promissory notes	2,604	3,988
Note Collateralized by Real Estate [Member] \| Note Payable Due August 2019 [Member]
Notes payable	128	192
	128	192
Note Collateralized by Real Estate [Member] \| Note 1 Due March 2019 [Member]
Notes payable	132	198
	132	198
Note Collateralized by Real Estate [Member] \| Note 2 Due March 2019 [Member]
Notes payable	307	468
	307	468
Note Collateralized by Real Estate [Member] \| Note Payable Due June 2016 [Member]
Notes payable	276	291
	276	291
Notes Collateralized by Aircraft Security Agreements [Member] \| Note Payable Due September 2017 [Member]
Notes payable	46	150
	46	150
Notes Collateralized by Aircraft Security Agreements [Member] \| Debt Instrument Due January 2020 [Member]
Notes payable	412	547
	412	547
Note Collateralized by BNSC's Assets and Compensation due under State Management Contract [Member] \| Debt Instrument Due May 2020 [Member]
Notes payable	3,560	4,602
	3,560	4,602
Note Collateralized by Equipment [Member] \| Note Payable Due April 2020 [Member]
Notes payable	98
	$ 98

The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19,20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
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