Other Financial Data - Schedule of Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 28, 2025	Jun. 29, 2025
Receivables, net:
Customer receivables	$ 58,603	$ 76,594
Allowance for uncollectible accounts	(2,070)	(2,451)
Reserves for quality claims	(757)	(912)
Net customer receivables	55,776	73,231
Banker's acceptance notes	976	1,334
Other receivables	1,218	818
Total receivables, net	57,970	75,383
Inventories:
Raw materials	40,483	48,752
Supplies	12,273	11,779
Work in process	3,815	5,246
Finished goods	50,920	61,116
Gross inventories	107,491	126,893
Net realizable value adjustment	(4,406)	(3,964)
Total inventories	103,085	122,929
Other current assets:
Prepaid expenses and other	3,249	3,475
Value-added taxes receivable	1,960	2,365
Vendor deposits	1,092	2,775
Contract assets	308	607
Total other current assets	6,609	9,222
Property, plant and equipment, net:
Gross property, plant and equipment	783,760	790,053
Less: accumulated depreciation	(607,581)	(608,133)
Less: accumulated amortization – finance leases	(9,972)	(8,997)
Total property, plant and equipment, net	166,207	172,923
Other non-current assets:
Grantor trust	2,525	2,310
Investment in unconsolidated affiliate	1,141	1,151
Intangible assets, net	519	573
Other	737	870
Total other non-current assets	4,922	4,904
Other current liabilities:
Payroll and fringe benefits	4,469	6,815
Incentive compensation	1,921	5,652
Utilities	1,435	2,236
Deferred revenue	970	1,236
Property taxes, interest and other	3,644	2,960
Total other current liabilities	12,439	18,899
Other long-term liabilities:
Nonqualified deferred compensation plan obligation	2,616	2,402
Uncertain tax positions	1,294	1,227
Other	229	260
Total other long-term liabilities	4,139	3,889
Land
Property, plant and equipment, net:
Gross property, plant and equipment	1,041	1,039
Land Improvements
Property, plant and equipment, net:
Gross property, plant and equipment	10,425	10,425
Building and Building Improvements
Property, plant and equipment, net:
Gross property, plant and equipment	126,872	126,720
Assets Held Under Finance Leases
Property, plant and equipment, net:
Gross property, plant and equipment	23,471	19,756
Machinery and Equipment
Property, plant and equipment, net:
Gross property, plant and equipment	585,222	593,771
Computers Software And Office Equipment
Property, plant and equipment, net:
Gross property, plant and equipment	24,937	25,400
Transportation Equipment
Property, plant and equipment, net:
Gross property, plant and equipment	10,475	10,789
Asset under Construction
Property, plant and equipment, net:
Gross property, plant and equipment	$ 1,317	$ 2,153