Note 5 - Derivative Financial Instruments - Derivatives Instruments, Statements of Financial Performance and Financial Position (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Oct. 31, 2020	Oct. 26, 2019	Oct. 31, 2020	Oct. 26, 2019
Gain (loss) before income taxes	$ 2,131	$ (619)	$ 7,211	$ (2,043)
Less income tax provision (benefit)	510	(148)	1,725	(489)
Net	1,621	(471)	5,486	(1,554)
(Loss) before income taxes	(12)	(1,170)	(1,844)	(2,614)
Less income tax (benefit)	(3)	(280)	(441)	(625)
Net	(9)	(890)	(1,403)	(1,989)
Net change to AOCI	$ 1,630	$ 419	$ 6,889	$ 435

Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount before tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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Amount after tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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