Long-Term Debt (Narrative) (Details) (USD $)	9 Months Ended
	Jan. 31, 2014	Apr. 30, 2013
Wells Fargo Credit Agreement [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 18,200,000
Number of term loans	2
Number of revolving lines of credit	1
Term Note A [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	12,200,000
Term loan amount	11,630,000	7,883,000
Quarterly principal payment	306,000
Note payable maturity date	Jun. 30, 2015
Reference rate	LIBOR
Stated interest rate, minimum	6.50%
Effective interest rate at period end	6.50%
Term Note B [Member]
Debt Instrument [Line Items]
Term loan amount	1,000,000	4,000,000
Note payable maturity date	Jun. 30, 2015
Reference rate	LIBOR
Stated interest rate, minimum	12.00%
Effective interest rate at period end	12.00%
Wells Fargo Revolving Line Of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	5,000,000
Term loan amount	$ 2,500,000	$ 5,500,000
Note payable maturity date	Jun. 30, 2015
Reference rate	LIBOR
Stated interest rate, minimum	6.50%
Effective interest rate at period end	6.50%
Minimum [Member] | Term Note A [Member]
Debt Instrument [Line Items]
Basis spread on variable reference rate	4.50%
Minimum [Member] | Term Note B [Member]
Debt Instrument [Line Items]
Basis spread on variable reference rate	9.00%
Minimum [Member] | Wells Fargo Revolving Line Of Credit [Member]
Debt Instrument [Line Items]
Basis spread on variable reference rate	4.50%
Maximum [Member] | Term Note A [Member]
Debt Instrument [Line Items]
Basis spread on variable reference rate	5.00%
Maximum [Member] | Term Note B [Member]
Debt Instrument [Line Items]
Basis spread on variable reference rate	10.00%
Maximum [Member] | Wells Fargo Revolving Line Of Credit [Member]
Debt Instrument [Line Items]
Basis spread on variable reference rate	5.00%