Basis of Presentation	6 Months Ended
	Jul. 03, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of PresentationThe accompanying unaudited consolidated financial statements of Kelly Services, Inc. (the “Company,” “Kelly,” “we” or “us”) have been prepared in accordance with Rule 10-01 of Regulation S-X and do not include all the information and notes required by generally accepted accounting principles (“GAAP”) for complete financial statements. In the opinion of management, all adjustments, including normal recurring adjustments, necessary for a fair statement of the results of the interim periods, have been made. The results of operations for such interim periods are not necessarily indicative of results of operations for a full year. The unaudited consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements and notes thereto for the fiscal year ended January 2, 2022, included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 17, 2022 (the 2021 consolidated financial statements). There were no changes in accounting policies as disclosed in the Form 10-K, with the exception of those described in the New Accounting Pronouncements footnote. The Company’s second fiscal quarter ended on July 3, 2022 (2022) and July 4, 2021 (2021), each of which contained 13 weeks. The corresponding June year-to-date periods for 2022 and 2021 each contained 26 weeks.Certain reclassifications have been made to the prior year's consolidated financial statements to conform to the current year's presentation.