Borrowings (Details) (USD $)	3 Months Ended
	Jul. 31, 2012
Line of Credit [Member]
Debt Instrument [Line Items]
Number of lines of credit	1
Line of credit facility borrowing capacity	$ 1,000,000
Unused line	696,000
Notes Collateralized by Aircraft Security Agreements [Member]
Debt Instrument [Line Items]
Notes payable	2,471,000
Notes Payable to Bank [Member]
Debt Instrument [Line Items]
Notes payable	1,878,000
Notes payable due date	Mar. 31, 2013
Number of notes	3
Notes for Real Estate [Member]
Debt Instrument [Line Items]
Notes payable	342,000
Number of notes	1
Note Collateralized by First and Second Position on All Assets of The Company [Member]
Debt Instrument [Line Items]
Notes payable	392,000
Number of notes	1
Notes Collateralized by Automobiles and Equipment [Member]
Debt Instrument [Line Items]
Notes payable	$ 209,000