Accounts Receivable and Unbilled Revenue, Net (Details) - USD ($) $ in Thousands	Mar. 27, 2020	Dec. 27, 2019
Receivables Net Current [Abstract]
Accounts receivable	$ 38,400	$ 35,884
Unbilled revenue	15,371	14,637
Allowance for doubtful accounts	(374)	(743)
Accounts receivable and unbilled revenue, net	$ 53,397	$ 49,778

Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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Amount of allowance for credit loss on accounts receivable, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value.

+ References

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Amount received for services rendered and products shipped, but not yet billed, for non-contractual agreements due within one year or the normal operating cycle, if longer.

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