Leases - Supplemental consolidated balance sheet information (Details) - USD ($) $ in Thousands	Sep. 26, 2026	Dec. 27, 2025
Operating Leases
Operating lease right-of-use assets	$ 1,154	$ 541
Other current liabilities	$ 424	619
Other current liabilities - extensible list	Other Liabilities, Current
Operating lease liabilities	$ 716	23
Total operating lease liabilities	1,140	642
Finance Leases
Property and equipment, at cost	488	488
Accumulated depreciation	(438)	(380)
Property and equipment, net	$ 50	108
Property and equipment, net - extensible list	Property and equipment, net
Other current liabilities		3
Other liabilities	$ 0	0
Other liabilities - extensible list	Other liabilities
Total finance lease liabilities		$ 3
Total finance lease liabilities - extensible list	us-gaap:AccruedLiabilitiesCurrent, Other liabilities

Finance Leases [Abstract]

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- Definition

Operating Lease [Abstract]

+ References

No definition available.

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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

+ References

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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease, classified as current.

+ References

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-Name Accounting Standards Codification
-Section 45
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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent.

+ References

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- Definition

Indicates line item in statement of financial position that includes noncurrent finance lease liability.

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Indicates line item in statement of financial position that includes finance lease liability.

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Amount, after accumulated amortization, of right-of-use asset from finance lease.

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- Definition

Amount of accumulated amortization of right-of-use asset from finance lease.

+ References

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- Definition

Amount, before accumulated amortization, of right-of-use asset from finance lease.

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- Definition

Indicates line item in statement of financial position that includes finance lease right-of-use asset.

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Present value of lessee's discounted obligation for lease payments from operating lease.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

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Indicates line item in statement of financial position that includes current operating lease liability.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.

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Amount of lessee's right to use underlying asset under operating lease.

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