Credit Facility (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Aug. 03, 2013	Jul. 12, 2012
Credit Facility [Line Items]
New Credit Agreement Date	Jul. 12, 2012
Maximum Borrowing Capacity, Credit Facility	$ 50.0
Maximum Borrowing Capacity, Letters of Credit	10.0
Deferred financing costs		0.4
Availability requirement, Percentage	10.00%
Availability requirement, Value	3.0
Dividends Allowed Under Credit Facility	10.0
Special Dividend Allowed Under Credit Facility	5.0
Ownership interest percentage held as collateral security	100.00%
Borrowings under the credit facility	0
Borrowing base	25.1
Open on-demand letters of credit	3.5
Available borrowing capacity under the credit facility	$ 18.6
Minimum [Member]
Credit Facility [Line Items]
Letters of credit fees (as a percent)	1.50%
Maximum [Member]
Credit Facility [Line Items]
Letters of credit fees (as a percent)	2.50%
Prime rate | Minimum [Member]
Credit Facility [Line Items]
Reference rate (as a percent)	1.00%
Prime rate | Maximum [Member]
Credit Facility [Line Items]
Reference rate (as a percent)	1.50%
LIBOR | Minimum [Member]
Credit Facility [Line Items]
Reference rate (as a percent)	2.00%
LIBOR | Maximum [Member]
Credit Facility [Line Items]
Reference rate (as a percent)	2.50%