Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Oct. 23, 2021	Jul. 24, 2021	Oct. 24, 2020	Jul. 25, 2020	Oct. 23, 2021	Oct. 24, 2020
Activity in accumulated other comprehensive loss
Beginning balance	$ 764,449	$ 782,146	$ 714,999	$ 716,306	$ 782,146	$ 716,306
Total other comprehensive income (loss)	(450)	(732)	1,354	2,218	(1,182)	3,572
Ending balance	785,682	764,449	754,649	714,999	785,682	754,649
Components of non-controlling interest
Beginning balance	764,449	782,146	714,999	716,306	782,146	716,306
Net income	40,358	25,266	35,304	4,679	65,624	39,983
Other comprehensive income (loss)	(450)	(732)	1,354	2,218	(1,182)	3,572
Ending balance	785,682	764,449	754,649	714,999	785,682	754,649
Accumulated other comprehensive income (loss)
Activity in accumulated other comprehensive loss
Beginning balance	(1,823)	(1,521)	(5,232)	(6,952)	(1,521)	(6,952)
Changes before reclassifications	(549)		1,214		(770)	2,904
Amounts reclassified to net income	73		61		152	126
Tax effect	146		0		(14)	(35)
Total other comprehensive income (loss)	(330)		1,275		(632)	2,995
Ending balance	(2,153)	(1,823)	(3,957)	(5,232)	(2,153)	(3,957)
Components of non-controlling interest
Beginning balance	(1,823)	(1,521)	(5,232)	(6,952)	(1,521)	(6,952)
Other comprehensive income (loss)	(330)		1,275		(632)	2,995
Ending balance	(2,153)	(1,823)	(3,957)	(5,232)	(2,153)	(3,957)
Translation adjustment
Activity in accumulated other comprehensive loss
Beginning balance	2,229	3,041	(278)	(1,891)	3,041	(1,891)
Changes before reclassifications	111		1,275		(701)	2,888
Amounts reclassified to net income	0		0		0	0
Tax effect	0		0		0	0
Total other comprehensive income (loss)	111		1,275		(701)	2,888
Ending balance	2,340	2,229	997	(278)	2,340	997
Components of non-controlling interest
Beginning balance	2,229	3,041	(278)	(1,891)	3,041	(1,891)
Other comprehensive income (loss)	111		1,275		(701)	2,888
Ending balance	2,340	2,229	997	(278)	2,340	997
Unrealized gain (loss) on marketable securities
Activity in accumulated other comprehensive loss
Beginning balance	818	370	491	449	370	449
Changes before reclassifications	(660)		(61)		(69)	16
Amounts reclassified to net income	(2)		(25)		2	(47)
Tax effect	164		21		17	8
Total other comprehensive income (loss)	(498)		(65)		(50)	(23)
Ending balance	320	818	426	491	320	426
Components of non-controlling interest
Beginning balance	818	370	491	449	370	449
Other comprehensive income (loss)	(498)		(65)		(50)	(23)
Ending balance	320	818	426	491	320	426
Net pension amortization and net actuarial loss
Activity in accumulated other comprehensive loss
Beginning balance	(4,870)	(4,932)	(5,445)	(5,510)	(4,932)	(5,510)
Changes before reclassifications	0		0		0	0
Amounts reclassified to net income	75		86		150	173
Tax effect	(18)		(21)		(31)	(43)
Total other comprehensive income (loss)	57		65		119	130
Ending balance	(4,813)	(4,870)	(5,380)	(5,445)	(4,813)	(5,380)
Components of non-controlling interest
Beginning balance	(4,870)	(4,932)	(5,445)	(5,510)	(4,932)	(5,510)
Other comprehensive income (loss)	57		65		119	130
Ending balance	(4,813)	(4,870)	(5,380)	(5,445)	(4,813)	(5,380)
Non-Controlling Interests
Activity in accumulated other comprehensive loss
Beginning balance	8,918	8,648	7,425	15,553	8,648	15,553
Total other comprehensive income (loss)	(120)	(430)	79	498	(550)	577
Ending balance	8,380	8,918	7,873	7,425	8,380	7,873
Components of non-controlling interest
Beginning balance	8,918	8,648	7,425	15,553	8,648	15,553
Net income	842	700	369	(119)	1,542	250
Other comprehensive income (loss)	(120)	(430)	79	498	(550)	577
Dividends distributed to joint venture minority partners	(1,260)		0		(1,260)	(8,507)
Ending balance	$ 8,380	$ 8,918	$ 7,873	$ 7,425	$ 8,380	$ 7,873