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Debt - Additional Information (Details) - USD ($) |  |  |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | ---
Jun. 22, 2020 | Mar. 17, 2020 | Oct. 25, 2019 | Jun. 24, 2016 | Dec. 26, 2020 | Dec. 28, 2019 | Dec. 31, 2016
Debt Instrument [Line Items] |  |  |  |  |  |  |
Term loans |  |  |  |  | $ 34,569,000 | $ 58,514,000 |
Derivative, notional amount |  |  |  |  |  |  | $ 95,600,000
FRT Term Loan |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt instrument, face amount |  |  | $ 23,400,000 |  |  |  |
Line of credit facility, expiration period |  |  | 3 years |  |  |  |
Long-term line of credit, quarterly repayment amount |  |  | $ 2,000,000.0 |  |  |  |
Interest rate at period end |  |  |  |  | 1.24% |  |
Term loans |  |  |  |  | $ 17,100,000 |  |
Building Term Loan |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt instrument, face amount | $ 18,000,000.0 |  |  |  |  |  |
Interest rate at period end |  |  |  |  | 1.90% |  |
Term loans |  |  |  |  | $ 17,500,000 |  |
Debt instrument, term | 15 years |  |  |  |  |  |
Debt instrument, interest payment term | 15 years |  |  |  |  |  |
Debt instrument, interest rate, effective percentage |  | 2.75% |  |  |  |  |
Building Term Loan | Interest Rate Contract |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Derivative, notional amount |  | $ 18,000,000.0 |  |  | $ 18,000,000.0 |  |
Derivative, floor interest rate |  | 0.00% |  |  |  |  |
Derivative, floor interest rate term |  | 1 year |  |  | 1 year |  |
LIBOR | Building Term Loan |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Basis spread on variable rate | 1.75% | 1.75% |  |  | 1.75% |  |
Euro Interbank Offered Rate (EURIBOR) | FRT Term Loan |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Basis spread on variable rate |  |  | 175.00% |  |  |  |
Senior Secured Term Loan |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Derivative, notional amount |  |  |  |  | $ 17,500,000 |  |
Senior Secured Term Loan | CMI Term Loan |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  | $ 150,000,000 |  |  |
Interest payment term |  |  |  | 5 years |  |  |
Debt principal payable in current year, percentage |  |  |  | 5.00% |  |  |
Debt principal payable in year two, percentage |  |  |  | 10.00% |  |  |
Debt principal payable in year three, percentage |  |  |  | 20.00% |  |  |
Debt principal payable in year four, percentage |  |  |  | 30.00% |  |  |
Debt principal payable in year five, percentage |  |  |  | 35.00% |  |  |
Senior Secured Term Loan | LIBOR | CMI Term Loan |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Basis spread on variable rate |  |  |  | 2.00% |  |  |
Senior Secured Term Loan | Base Rate | CMI Term Loan |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Basis spread on variable rate |  |  |  | 1.00% |  |  |

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- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
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