Summary of Significant Accounting Policies - Summary of IT Solutions and IT and Other Staffing Revenue as Percentage of Total Revenue (Details) - Product Concentration Risk [Member] - Sales Revenue, Services, Net [Member]	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Product Information [Line Items]
Revenue, percent	100.00%	100.00%	100.00%	100.00%
IT Solutions [Member]
Product Information [Line Items]
Revenue, percent	31.60%	29.90%	31.00%	30.00%
IT and Other Staffing [Member]
Product Information [Line Items]
Revenue, percent	68.40%	70.10%	69.00%	70.00%