Summary of Significant Accounting Policies - Description of Business and Fiscal Year (Details)	12 Months Ended
Dec. 28, 2019 segment item	Dec. 29, 2018 item	Dec. 30, 2017 item
Description of Business
Number of broad areas of consulting services	2
Number of business segment \| segment	1
Fiscal Year
Number of weeks periodically contained in a fiscal year	53
Number of weeks in a fiscal year	52	52	52

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

No definition available.

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration