Summary of Significant Accounting Policies - Basis of Presentation and Consolidation (Details)	6 Months Ended	9 Months Ended
	Sep. 27, 2020	Sep. 25, 2020 segment Market
Accounting Policies [Abstract]
Description of the nature of an event or transaction	Through the date of this filing, about 10% of the Company’s billable resources have been idled since the beginning of the COVID-19 pandemic in March 2020. To offset this reduction in billable resources, during April 2020, the Company took a number of actions to reduce costs and mitigate the potential impact of the COVID-19 pandemic, including a full-time furlough of about 5% of its North American non-billable staff, and a reduced work schedule (20% furlough) for nearly all other non-billable staff, including senior management, that are not directly or indirectly related to business development. The reduced work schedule for the non-billable staff, including senior management, ended on September 27, 2020.
Number of operating segments | segment		1
Number of vertical market focus areas | Market		5