Interim Information	6 Months Ended
Interim Information	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interim Information	INTERIM INFORMATION Readers of this quarterly report should refer to the audited financial statements of Jones Lang LaSalle Incorporated ("JLL," which may also be referred to as "the Company" or as "we," "us" or "our") for the year ended December 31, 2021, which are included in our 2021 Annual Report on Form 10-K, filed with the United States Securities and Exchange Commission ("SEC") and also available on our website (www.jll.com), since we have omitted from this quarterly report certain footnote disclosures which would substantially duplicate those contained in such audited financial statements. You should also refer to the "Summary of Critical Accounting Policies and Estimates" section within Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations and to Note 2, Summary of Significant Accounting Policies, in the Notes to Consolidated Financial Statements in our 2021 Annual Report on Form 10-K for further discussion of our significant accounting policies and estimates. Our Condensed Consolidated Financial Statements as of June 30, 2022, and for the periods ended June 30, 2022 and 2021, are unaudited. In the opinion of management, we have included all adjustments (consisting solely of normal recurring adjustments) necessary for a fair presentation of the Condensed Consolidated Financial Statements for these interim periods. We have also reclassified certain prior year amounts to conform to the current presentation, specifically the incorporation of directly reimbursed expenses within Compensation and benefits, and Operating, administrative and other on our Condensed Consolidated Statements of Comprehensive Income, compared with its historical separate presentation. Historically, our quarterly revenue and profits have tended to increase from quarter to quarter as the year progresses. This is the result of a general focus in the real estate industry on completing transactions by calendar year end, while certain expenses are recognized evenly throughout the year. Growth in our Property Management and Workplace Management businesses as well as other annuity-based services has, to an extent, lessened the seasonality in our revenue and profits during the past several years. Within our Markets Advisory and Capital Markets segments, revenue from transaction-based activities is driven by the size and timing of our clients' transactions and can fluctuate significantly from period to period. Our LaSalle Investment Management ("LaSalle") segment generally earns investment-generated performance fees on clients' real estate investment returns when assets are sold, the timing of which is geared toward the benefit of our clients, as well as co-investment equity gains and losses, primarily dependent on underlying valuations. A significant portion of our compensation and benefits expense is from incentive compensation plans, which we generally accrue throughout the year based on progress toward annual performance targets. This process can result in significant fluctuations in quarterly compensation and benefits expense from period to period. Non-variable operating expenses, which we recognize when incurred during the year, are relatively constant on a quarterly basis. We provide for the effects of income taxes on interim financial statements based on our estimate of the effective tax rate for the full year, which we base on forecasted income by country and expected enacted tax rates. As required, we adjust for the impact of discrete items in the quarters in which they occur. Changes in the geographic mix of income can impact our estimated effective tax rate. As a result of the items mentioned above, the results for the periods ended June 30 are not fully indicative of what our results will be for the full fiscal year. Change in Reporting Segments Effective January 1, 2022, we changed from our geographic-centric Real Estate Services segments of Americas, EMEA and Asia Pacific to global business line segments of Markets Advisory, Capital Markets, Work Dynamics and JLL Technologies. Our real estate investment management business, LaSalle, continues as a reporting segment. As our segment financial results are presented on this global business line view, the comparable period has been recast to align with the new reporting structure. Refer to Note 2, Revenue Recognition, and Note 3, Business Segments, for additional information, including detail financial information, on our segments.