Billed and Unbilled Receivables - Activity in the Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Receivables [Abstract]
Balance as of the beginning of the year	$ 4,546	$ 3,642
Provision for doubtful accounts	1,239	797	$ 586
Write-offs of uncollectible accounts	(714)	(301)
Other	0	408
Balance as of the end of the year	$ 5,071	$ 4,546	$ 3,642