Interest Rate Derivatives (Details) (USD $) In Thousands, unless otherwise specified		3 Months Ended	9 Months Ended	12 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 27, 2013	Jan. 22, 2012 Interest rate cap contracts	Jan. 22, 2012 Interest rate cap contracts	Apr. 29, 2012 Interest rate cap contracts	Jan. 27, 2013 Interest rate swap contracts	Jan. 22, 2012 Interest rate swap contracts	Jan. 27, 2013 Interest rate swap contracts	Jan. 22, 2012 Interest rate swap contracts	Apr. 29, 2012 Interest rate swap contracts
Interest Rate Derivatives
Aggregate notional value					$ 50,000		$ 50,000
Fair value of derivative liability					1,248		1,248		2,493
Deferred income tax benefit				8			238		506
Change in unrealized loss on our derivatives qualifying for hedge accounting		0	26
Weighted average fixed LIBOR interest rate (as a percent)					3.995%		3.995%
Derivative income					460	749	1,245	2,116
Accumulated OCI amortization					148	328	445	1,164
Change in deferred taxes					90	198	268	700
Derivative income (expense)					(238)	(526)	(713)	(1,864)
Amount of accumulated other comprehensive income (loss) related to interest rate swap contracts and interest rate cap contracts maturing within the next twelve months, net of tax	396
Amount of tax in accumulated other comprehensive income (loss) related to interest rate swap contracts and interest rate cap contracts maturing within the next twelve months	$ 238