CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Apr. 28, 2013	Apr. 29, 2012	Apr. 24, 2011
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Deferred hedge adjustment, income tax provision	$ 357	$ 789	$ 3,408
Unrealized gain (loss) on interest rate cap contracts, income tax provision (benefit)	$ 8	$ 41	$ (19)

Tax effect on reclassification adjustment for accumulated gains and losses from interest rate swap contracts designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period.

No definition available.

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Namespace Prefix:	isle_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration