Leases - Components of lease cost (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 26, 2020	Dec. 28, 2019
Lease Cost [Abstract]
Operating lease cost	$ 9,764	$ 5,625
Variable lease costs not included in liability	1,643	1,064
Finance lease cost:
Amortization of right-of-use asset	1,185	306
Interest on lease liabilities	143	56
Total finance lease cost	$ 1,328	$ 362

Finance lease abstract.

No definition available.

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- Definition

Amount of interest paid on finance lease liability.

+ References

+ Details

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- Definition

Amount of amortization expense attributable to right-of-use asset from finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=121568110&loc=SL77918982-209971

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- Definition

Amount of lease cost recognized by lessee for lease contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
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-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980

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- References

No definition available.

+ Details

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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI http://asc.fasb.org/extlink&oid=121568110&loc=SL77918982-209971

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
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-Section 50
-Paragraph 4
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-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980

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- Definition

Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

+ References

+ Details

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