Summary of Significant Accounting Policies - Summary of IT Solutions and IT and Other Staffing Revenue as Percentage of Total Revenue (Details)	3 Months Ended
Mar. 27, 2020	Mar. 29, 2019
Product Information [Line Items]
Revenue, percent	100.00%
Product Concentration Risk [Member] \| Sales Revenue, Services, Net [Member]
Product Information [Line Items]
Revenue, percent	100.00%	100.00%
Product Concentration Risk [Member] \| Sales Revenue, Services, Net [Member] \| IT Solutions [Member]
Product Information [Line Items]
Revenue, percent	33.40%	34.40%
Product Concentration Risk [Member] \| Sales Revenue, Services, Net [Member] \| IT and Other Staffing [Member]
Product Information [Line Items]
Revenue, percent	66.60%	65.60%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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