Lease - Lease Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Leases [Abstract]
Operating lease cost	$ 1,873	$ 2,641	$ 6,556	$ 6,868
Variable lease cost	681	837	2,183	2,360
Total lease cost	2,554	3,478	8,739	9,228
Cash paid for amounts included in the measurement of operating lease liabilities	3,134	2,655	7,772	6,937
Right-of-Use assets obtained in exchange for operating lease obligations	$ 69	$ 0	$ 1,740	$ 10,305

Amount of lease cost recognized by lessee for lease contract.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980

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- References

No definition available.

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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
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-Section 55
-Paragraph 53
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- Definition

Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of increase in right-of-use asset obtained in exchange for operating lease liability.

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-Publisher FASB
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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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