Long-Term Debt (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Jun. 30, 2011	Apr. 30, 2013	Apr. 30, 2012
Debt Instrument [Line Items]
Loss on extinguishment of debt			$ (2,166,000)
Revolving credit agreement, amount		8,000,000
Term loan amount		17,689,000	21,251,000
Reference rate		LIBOR
Basis spread on variable reference rate		5.00%
Stated interest rate, minimum		6.50%
Amount outstanding on revolver		5,500,000
Capitalized loan costs	600,000
Annual payment on debt		400,000
Term Note A [Member]
Debt Instrument [Line Items]
Term loan amount	12,000,000	7,883,000	11,100,000
Reference rate		LIBOR
Basis spread on variable reference rate	5.00%	5.00%
Stated interest rate, minimum		6.50%
Annual payment on debt		1,200,000
Term Note B [Member]
Debt Instrument [Line Items]
Term loan amount	4,000,000	4,000,000	4,000,000
Reference rate		LIBOR
Basis spread on variable reference rate	10.00%	10.00%
Stated interest rate, minimum		12.00%
Wells Fargo Revolving Line Of Credit [Member]
Debt Instrument [Line Items]
Revolving credit agreement, amount	8,000,000
Term loan amount		5,500,000	5,500,000
Reference rate		LIBOR
Basis spread on variable reference rate	5.00%	5.00%
Stated interest rate, minimum		6.50%
Hercules Term Loan and Credit Facility [Member]
Debt Instrument [Line Items]
Loss on extinguishment of debt	2,200,000
Unamortized loan costs	1,000,000
Warrant discounts	800,000
Prepayment fees	$ 400,000
Minimum [Member] | Term Note A [Member]
Debt Instrument [Line Items]
Basis spread on variable reference rate	1.50%
Minimum [Member] | Term Note B [Member]
Debt Instrument [Line Items]
Basis spread on variable reference rate	2.00%