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		9 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Sep. 29, 2017	Sep. 30, 2016
Product Information [Line Items]
Revenue, percent	100.00%	100.00%	100.00%	100.00%
IT Solutions [Member]
Product Information [Line Items]
Revenue, percent	29.60%	28.30%	29.80%	29.40%
IT and Other Staffing [Member]
Product Information [Line Items]
Revenue, percent	70.40%	71.70%	70.20%	70.60%