| Summary of Significant Accounting Policies Summary of SIgnificant Accounting Policies (Policies) | 12 Months Ended |
| Dec. 31, 2018 |
| Accounting Policies [Abstract] | |
| Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] | Principles of Consolidation Our Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") and include the accounts of JLL and its majority-owned and controlled subsidiaries. Intercompany balances and transactions have been eliminated. Investments in real estate ventures over which we exercise significant influence, but do not control, are accounted for either at fair value or under the equity method. When applying principles of consolidation, we begin by determining whether an investee entity is a variable interest entity ("VIE") or a voting interest entity. U.S. GAAP draws a distinction between voting interest entities, which are embodied by common and traditional corporate and certain partnership structures, and VIEs, broadly defined as entities for which control is achieved through means other than voting rights. For voting interest entities, the interest holder with control through majority ownership and majority voting rights consolidates the entity. For VIEs, determination of the "primary beneficiary" dictates the accounting treatment. We identify the primary beneficiary of a VIE as the enterprise that has both (i) the power to direct the activities of the VIE that most significantly impact the entity's economic performance and (ii) the obligation to absorb losses or receive benefits of the VIE that could potentially be significant to the VIE. We perform the primary beneficiary analysis as of the inception of our investment and upon the occurrence of a reconsideration event. When we determine we are the primary beneficiary of a VIE, we consolidate the VIE; when we determine we are not the primary beneficiary of the VIE, we account for our investment in the VIE at fair value or under the equity method, based upon an election made at the time of investment. Our determination of the appropriate accounting method to apply for unconsolidated investments is based on the level of influence we have in the underlying entity. When we have an asset advisory contract with a real estate limited partnership in which we also hold an ownership interest, the combination of our limited partner interest and the advisory agreement generally provides us with significant influence over such real estate limited partnership. Accordingly, we account for such investments either at fair value or under the equity method. We eliminate transactions with such subsidiaries to the extent of our ownership in such subsidiaries. For less-than-wholly-owned consolidated subsidiaries, noncontrolling interest is the portion of equity not attributable, directly or indirectly, to JLL. We evaluate whether noncontrolling interests possess any redemption features outside of our control. If such features exist, the noncontrolling interests are presented outside of permanent equity on the Consolidated Balance Sheets within Redeemable noncontrolling interest. Redeemable noncontrolling interests are adjusted to the greater of their fair value or carrying value as of each balance sheet date through a charge to Additional paid-in capital, if necessary. If classification and presentation outside of permanent equity is not considered necessary, noncontrolling interests are presented as a component of permanent equity on the Consolidated Balance Sheets. We report revenues, expenses and net income (loss) from less-than-wholly-owned consolidated subsidiaries at the consolidated amounts, including both the amounts attributable to the Company and noncontrolling interests; the income or loss attributable to the noncontrolling interest holders is reflected in Net income attributable to noncontrolling interest on the Consolidated Statements of Comprehensive Income. Changes in amounts attributable to noncontrolling interests are reflected in the Consolidated Statements of Changes in Equity. Changes in amounts attributable to redeemable noncontrolling interests are presented in the following table. ($ in millions) Redeemable noncontrolling interests as of December 31, 2015 $ 11.1 Acquisition of redeemable noncontrolling interest (1) (3.6 ) Net income 0.1 Impact of exchange rate movements (0.8 ) Redeemable noncontrolling interests as of December 31, 2016 6.8 Acquisition of redeemable noncontrolling interest (1) (3.5 ) Net loss (0.1 ) Impact of exchange rate movements 0.6 Redeemable noncontrolling interests as of December 31, 2017 3.8 Acquisition of redeemable noncontrolling interest (1) (3.8 ) Redeemable noncontrolling interests as of December 31, 2018 $ — (1) Reflects our redemption of a portion of the redeemable noncontrolling interest related to our 2014 acquisition of Tenzing AB and includes $2.3 million , $1.1 million , and $0.8 million representing the difference between the redemption value and the carrying value of the acquired interest as of December 31, 2018 , 2017 , and 2016, respectively. |
| Use of Estimates, Policy [Policy Text Block] | Use of Estimates The preparation of the Consolidated Financial Statements in conformity with U.S. GAAP requires us to make estimates and assumptions about future events that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities as of the dates of the financial statements, and the reported amounts of revenue and expenses during the reporting periods. Such estimates include the value and allocation of purchase consideration, valuation of accounts receivable, reimbursable receivables, warehouse receivables, investments in real estate ventures, goodwill, intangible assets, derivative financial instruments, other long-lived assets, earn-out liabilities, legal contingencies, assumptions used in the calculation of income taxes, incentive compensation, self-insurance program liabilities, and retirement and other post-employment benefits, among others. These estimates and assumptions are based on management's best estimate and judgment. We evaluate these estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, which we believe to be reasonable under the circumstances. We adjust such estimates and assumptions when facts and circumstances dictate. Market factors, such as illiquid credit markets, volatile equity markets and foreign currency exchange rate fluctuations can increase the uncertainty in such estimates and assumptions. Because future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods. Although actual amounts may differ from such estimated amounts, we believe such differences are not likely to be material. |
| Revenue Recognition, Services, Commissions [Policy Text Block] | Leasing Leasing revenue is earned from brokerage commissions as we represent tenants and/or landlords in connection with real estate leases. Our performance obligation is to facilitate the execution of a lease agreement, which is satisfied at a point in time, upon lease execution. Generally, we are either entitled to the full consideration upon lease execution or in part upon lease execution with the remainder upon the occurrence of a future event outside of our control (e.g. tenant occupancy, lease commencement, or rent commencement). The majority of the events that preclude our entitlement to the full consideration upon lease execution are considered to be “normal course of business” and, therefore, do not result in a constraint upon the recognition of revenue. In the infrequent instance our fee entitlement in a contract with a customer is predicated on the occurrence of a future event(s) uncertain of occurring, we constrain the recognition of revenue until the uncertainty is resolved or the future event occurs. Generally, less than 5% of our Leasing revenue recognized in a period had previously been constrained. |
| Revenue Recognition, Real Estate Transactions, Policy [Policy Text Block] | Capital Markets Capital Markets provides brokerage and other services for capital transactions, such as real estate sales or loan originations and refinancings. Our performance obligation is to facilitate the execution of capital transactions, and we are generally entitled to the full consideration at the point in time upon which our performance obligation is satisfied, at which time we recognize revenue. Our mortgage banking and servicing operations - such as activities related to mortgage servicing rights ("MSR" or "MSRs"), loan origination fees and servicing income - are excluded from the scope of ASC Topic 606, Revenue from Contracts with Customers, ("ASC 606"). Such out-of-scope revenue was $135.8 million , $126.9 million , and $104.6 million for the years ended December 31, 2018, 2017, and 2016, respectively. |
| Revenue Recognition, Services, Management Fees [Policy Text Block] | Property Management provides on-site day-to-day real estate management services for owners of office, industrial, retail, multifamily residential and various other types of properties, representing a series of daily performance obligations delivered over time. Pricing is generally in the form of a monthly management fee based upon property-level cash receipts, square footage under management or some other variable metric. Although we are principal in limited situations, we generally act as agent on behalf of our Property Management clients in relation to third-party vendors and subcontractors engaged to deliver operational services to our clients' properties. In these situations, we arrange, but do not control, the services provided by third-party vendors and subcontractors prior to the transfer of the services to the client. As a result, the costs incurred on behalf of clients, along with the corresponding revenue, are presented net on our Consolidated Statements of Comprehensive Income. Facility Management primarily provides comprehensive, on-site day-to-day real estate management services to corporations and institutions across a broad range of industries that outsource the management of the real estate they occupy, representing a series of daily performance obligations delivered over time. Pricing generally includes a management fee and, in many instances, an incentive fee or other form of variable consideration. Although we may act as agent on behalf of our clients with respect to certain mandates, we generally act as principal for our Facility Management contracts with respect to third-party vendors and subcontractors engaged to deliver operational services to our clients' facilities. In these situations, we control the services provided by such third-party vendors and subcontractors prior to the transfer of the services to the client. As a result, the costs incurred on behalf of our clients, along with the corresponding reimbursement revenue, are presented gross on our Consolidated Statements of Comprehensive Income. |
| Advisory, Consulting and Other [Policy Text Block] | Advisory, Consulting and Other includes a variety of different service offerings, whereby our performance obligation is to provide services as specified in the contract. Occasionally, our entitlement to consideration is predicated on the occurrence of an event such as the delivery of a report for which client acceptance is required. However, except for event-driven point-in-time transactions, the majority of services provided within this service line are delivered over time due to the continuous transfer of control to our clients. |
| Management and Investment Advisory Fees, Policy [Policy Text Block] | LaSalle provides real estate investment management services to clients and earns consideration in the form of advisory fees, transaction fees and incentive fees. Typically, our performance obligation is to manage clients’ capital for a specified period of time and is delivered as a series of daily performance obligations over time. Revenue recognition for transaction and incentive fees is generally constrained until all contingencies have cleared due to the possibility of a significant reversal until completion of the events necessary to realize the associated consideration. Substantially all incentive fees recognized as revenue were previously constrained. |
| Revenue Recognition, Policy [Policy Text Block] | Revenue Recognition We earn revenue from the following: • Leasing; • Capital Markets; • Property & Facility Management; • Project & Development Services; • Advisory, Consulting and Other; and • LaSalle. Leasing Leasing revenue is earned from brokerage commissions as we represent tenants and/or landlords in connection with real estate leases. Our performance obligation is to facilitate the execution of a lease agreement, which is satisfied at a point in time, upon lease execution. Generally, we are either entitled to the full consideration upon lease execution or in part upon lease execution with the remainder upon the occurrence of a future event outside of our control (e.g. tenant occupancy, lease commencement, or rent commencement). The majority of the events that preclude our entitlement to the full consideration upon lease execution are considered to be “normal course of business” and, therefore, do not result in a constraint upon the recognition of revenue. In the infrequent instance our fee entitlement in a contract with a customer is predicated on the occurrence of a future event(s) uncertain of occurring, we constrain the recognition of revenue until the uncertainty is resolved or the future event occurs. Generally, less than 5% of our Leasing revenue recognized in a period had previously been constrained. Capital Markets Capital Markets provides brokerage and other services for capital transactions, such as real estate sales or loan originations and refinancings. Our performance obligation is to facilitate the execution of capital transactions, and we are generally entitled to the full consideration at the point in time upon which our performance obligation is satisfied, at which time we recognize revenue. Our mortgage banking and servicing operations - such as activities related to mortgage servicing rights ("MSR" or "MSRs"), loan origination fees and servicing income - are excluded from the scope of ASC Topic 606, Revenue from Contracts with Customers, ("ASC 606"). Such out-of-scope revenue was $135.8 million , $126.9 million , and $104.6 million for the years ended December 31, 2018, 2017, and 2016, respectively. Property & Facility Management Property Management provides on-site day-to-day real estate management services for owners of office, industrial, retail, multifamily residential and various other types of properties, representing a series of daily performance obligations delivered over time. Pricing is generally in the form of a monthly management fee based upon property-level cash receipts, square footage under management or some other variable metric. Although we are principal in limited situations, we generally act as agent on behalf of our Property Management clients in relation to third-party vendors and subcontractors engaged to deliver operational services to our clients' properties. In these situations, we arrange, but do not control, the services provided by third-party vendors and subcontractors prior to the transfer of the services to the client. As a result, the costs incurred on behalf of clients, along with the corresponding revenue, are presented net on our Consolidated Statements of Comprehensive Income. Facility Management primarily provides comprehensive, on-site day-to-day real estate management services to corporations and institutions across a broad range of industries that outsource the management of the real estate they occupy, representing a series of daily performance obligations delivered over time. Pricing generally includes a management fee and, in many instances, an incentive fee or other form of variable consideration. Although we may act as agent on behalf of our clients with respect to certain mandates, we generally act as principal for our Facility Management contracts with respect to third-party vendors and subcontractors engaged to deliver operational services to our clients' facilities. In these situations, we control the services provided by such third-party vendors and subcontractors prior to the transfer of the services to the client. As a result, the costs incurred on behalf of our clients, along with the corresponding reimbursement revenue, are presented gross on our Consolidated Statements of Comprehensive Income. Project & Development Services Project & Development Services provides short-term construction-related services ranging from general contracting to project management for owners and occupiers of real estate. Depending on the terms of our engagement, our performance obligation is either to arrange for the completion of a project or to assume responsibility for completing a project on behalf of a client. Our obligations to clients are satisfied over time due to the continuous transfer of control of the underlying asset. Therefore, we recognize revenue over time, generally using input measures (e.g. to-date costs incurred relative to total estimated costs at completion). Typically, we are entitled to consideration at distinct milestones over the term of an engagement. For certain contracts where we assume responsibility for completing a project, we control the services provided by third-party vendors and subcontractors prior to transfer of the assets to the client. In these situations, the costs incurred on behalf of clients, along with the associated reimbursement revenue are presented gross on our Consolidated Statements of Comprehensive Income. For situations in which we act as agent on behalf of clients, costs incurred and the associated revenue are presented net on our Consolidated Statements of Comprehensive Income. Advisory, Consulting and Other Advisory, Consulting and Other includes a variety of different service offerings, whereby our performance obligation is to provide services as specified in the contract. Occasionally, our entitlement to consideration is predicated on the occurrence of an event such as the delivery of a report for which client acceptance is required. However, except for event-driven point-in-time transactions, the majority of services provided within this service line are delivered over time due to the continuous transfer of control to our clients. LaSalle LaSalle provides real estate investment management services to clients and earns consideration in the form of advisory fees, transaction fees and incentive fees. Typically, our performance obligation is to manage clients’ capital for a specified period of time and is delivered as a series of daily performance obligations over time. Revenue recognition for transaction and incentive fees is generally constrained until all contingencies have cleared due to the possibility of a significant reversal until completion of the events necessary to realize the associated consideration. Substantially all incentive fees recognized as revenue were previously constrained. Contract Costs Expenses, primarily employee commissions, incurred on leasing and capital markets transactions represent substantially all our incremental costs to obtain revenue contracts. We apply the applicable practical expedient offered by ASC Topic 606 when the amortization period is one year or less and, therefore, recognize these costs as an operating expense as they are incurred. We also incur costs to fulfill revenue contracts, primarily related to transition costs incurred prior to delivering Property & Facility Management services. These costs are not expensed as incurred but are deferred and amortized as an operating expense over the expected life of the contract in accordance with the transfer of related services. These deferred costs are assessed periodically for impairment. Contract Assets Contract assets include amounts recognized as revenue for which we are not yet entitled to payment for reasons other than the passage of time, but that do not constrain revenue recognition. As of December 31, 2018 and December 31, 2017 , we had $396.2 million and $236.0 million of contract assets, respectively, which are included in Short-term contract assets and Other assets on the Consolidated Balance Sheets. Contract Liabilities Contract liabilities include advance payments related to performance obligations that have not yet been satisfied. As of December 31, 2018 and December 31, 2017 , we had $98.9 million and $73.7 million of contract liabilities, respectively, which are included in Short-term contract liabilities and deferred income on our Consolidated Balance Sheets. The majority of contract liabilities are recognized as revenue within 90 days. Deferred Income Deferred income includes payments received from customers for which we have satisfied our performance obligations but are not yet able to recognize the related revenue because of contractual requirements. Remaining Performance Obligations Remaining performance obligations represent the aggregate transaction price for contracts where our performance obligations have not yet been satisfied. As of December 31, 2018 , the aggregate amount of transaction price allocated to remaining performance obligations represented approximately 5% of our total revenue. In accordance with ASC Topic 606, excluded from the aforementioned remaining performance obligations are (i) amounts attributable to contracts expected to be completed within 12 months and (ii) variable consideration for services performed as a series of daily performance obligations, such as property and facility management contracts and LaSalle advisory contracts. Contracts within these businesses represent a significant portion of our contracts with customers not expected to be completed within 12 months. |
| Cash and Cash Equivalents, Policy [Policy Text Block] | Cash and Cash Equivalents We consider all highly-liquid investments purchased with maturities of less than three months to be cash equivalents. The carrying amount of cash equivalents approximates fair value due to the short-term maturity of these investments. |
| Trade and Other Accounts Receivable, Policy [Policy Text Block] | Financing Receivables We account for Trade receivables, Notes and other receivables, Long-term receivables, Reimbursable receivables, and Warehouse receivables as financing receivables. Trade Receivables Pursuant to contractual arrangements, Trade receivables, net of allowances include unbilled amounts of $531.4 million and $505.6 million as of December 31, 2018 and 2017 , respectively. We estimate the allowance necessary to provide for uncollectible accounts receivable. The estimate includes specific amounts for which payment has become unlikely. We also base this estimate on historical experience combined with a review of current developments and client credit quality. The process by which we calculate the allowance begins with the individual business units where specific accounts for which collectability is uncertain are identified and reserved as part of an overall reserve that is formulaic and driven by the age profile of the receivables and our historical experience. We then review these allowances on a quarterly basis to ensure they are appropriate. After all collection efforts have been exhausted by management, the outstanding balance considered not collectible is written off against the allowance. The following table details the changes in the allowance for uncollectible receivables. ($ in millions) 2018 2017 2016 Allowance as of January 1, $ 51.3 37.1 23.2 Charged to income 18.8 26.3 21.3 Write-off of uncollectible receivables (13.9 ) (14.2 ) (7.6 ) Reserves acquired from acquisitions — — 0.3 Impact of exchange rate movements and other (4.2 ) 2.1 (0.1 ) Allowance as of December 31, $ 52.0 51.3 37.1 |
| Notes and Other Recievables and Long-Term Receivables [Policy Text Block] | Notes and Other Receivables and Long-Term Receivables We make ongoing assessments of the collectability of outstanding Notes and other receivables and Long-term receivables, considering both objective and subjective factors such as the age profile of outstanding balances, the contractual terms of repayment, and credit quality. Aspects of credit quality considered in our assessments of collectability include historical experience, current developments and the status of our broader business relationship with the obligor. We record an allowance against the outstanding balance when our assessments result in a determination that payment has become unlikely. After all collection efforts have been exhausted by management, the outstanding balance considered uncollectible is written off against the reserve. Historically, credit quality deterioration to the point of impairment or non-performance in our Notes and other receivables and Long-term receivables has been limited and has not had a material impact on the Consolidated Financial Statements. |
| Reimbursable Receivables [Policy Text Block] | Reimbursable Receivables We recognize Reimbursable receivables for costs incurred on behalf of clients, primarily while performing Property & Facility Management services. These costs include direct reimbursements, primarily payroll and third-party vendor and subcontractor costs. As our clients are contractually obligated to reimburse us for these costs, we only record an allowance based on specific identification of an uncollectible reimbursable receivable. Reimbursable receivables relate to our Reimbursable payables, which are typically satisfied on a pay-when-paid basis. |
| Warehouse Receivables and Facilities [Policy Text Block] | Warehouse Receivables We classify Warehouse receivables as held-for-sale as they represent originated mortgage loans for which we have simultaneously executed commitments to sell to a third-party investor, primarily the Government National Mortgage Association ( Ginnie Mae ), the Federal National Mortgage Association ( Fannie Mae ), and the Federal Home Loan Mortgage Corporation ( Freddie Mac ). These loans (also referred to as "Warehouse receivables") are funded directly to borrowers by our warehouse facilities and are generally repaid within a 45-day period after origination when the third-party investor buys the loan(s); upon surrender of control over each loan, we account for the transfer as a sale. Warehouse receivables are measured and reported at fair value in accordance with our entity-wide election of the fair value option. As such, increases or decreases in the fair value of loans (originated after this election) are recognized as Revenue on the Consolidated Statements of Comprehensive Income. Historically, we have not experienced credit quality deterioration or balances considered uncollectible with respect to our Warehouse receivables. We generally retain certain servicing rights upon sale of the mortgage loan (refer to the Mortgage Servicing Rights section below). We typically retain no exposure for credit losses on loans subsequent to sale, except for loans under Fannie Mae's Delegated Underwriting and Servicing ("DUS") program. See Note 13, Commitments and Contingencies , for additional information on the risk of loss retained related to DUS program loans. |
| Mortgage Servicing Rights [Policy Text Block] | Mortgage Servicing Rights We generally retain certain servicing rights in connection with the origination and sale of Warehouse receivables. We initially record mortgage servicing rights ("MSR" or "MSRs") based on the fair value of these rights on the date the loans are sold, which could result in net gains which we recognize as Revenue on the Consolidated Statements of Comprehensive Income. As of December 31, 2018 and 2017 , we had $193.8 million and $186.7 million , respectively, of MSRs carried at the lower of amortized cost or fair value in Identified intangibles on the Consolidated Balance Sheets. We amortize servicing rights over the estimated period that net servicing income is projected to be received. In addition, we evaluate MSR intangible assets for impairment on a quarterly basis, or more frequently if circumstances or events indicate a change in fair value. Other than write-offs due to prepayments of sold Warehouse receivables for which we retained the servicing rights (generally during only the last six months of loan term given the punitive contractual terms of any earlier prepayment), there have been no instances of impairment during the three-year period ended December 31, 2018 . However, an increase in loan prepayment activity or deterioration in the credit quality of borrowers could result in a decrease to our MSR balance. MSRs do not actively trade in an open market with readily available observable prices; therefore, if necessary, the fair value of these rights would be determined in part based on certain assumptions and judgments that are unobservable within the fair value hierarchy, including the estimation of the present value of future cash flows to be realized from servicing the underlying mortgages. T he estimated fair value of MSRs was $246.8 million and $220.1 million as of December 31, 2018 and 2017 , respectively. |
| Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] | Restricted Cash Restricted cash primarily consists of cash amounts set aside to satisfy legal or contractual requirements arising in the normal course of business. We are restricted in our ability to withdraw these funds other than for their specified use. Restricted cash was included in Prepaid and other current assets on the Consolidated Balance Sheets. |
| Property, Plant and Equipment, Policy [Policy Text Block] | Property and Equipment We record property and equipment at cost and depreciate these assets over their relevant useful lives. We capitalize certain direct costs relating to internal-use software development when incurred during the application development phase. We evaluate property and equipment for impairment whenever events or circumstances indicate the carrying value of an asset group may not be recoverable. We record an impairment loss to the extent the carrying value exceeds the estimated fair value. We did not recognize any significant impairment losses related to property and equipment during the three years ended December 31, 2018 . We calculate depreciation on property and equipment for financial reporting purposes by using the straight-line method based on the estimated useful lives of our assets. Depreciation expense related to property and equipment for the years ended December 31, 2018 , 2017 and 2016 was $156.5 million , $136.0 million , and $117.7 million , respectively. The following table shows the gross value of major asset categories and the standard depreciable lives, as of December 31, 2018 , for each of these asset categories. December 31, ($ in millions) 2018 2017 Depreciable Life Furniture, fixtures and equipment $ 98.7 96.7 3 to 13 years Computer equipment and software 683.6 635.1 2.5 to 10 years Leasehold improvements 274.0 260.6 1 to 10 years Other (1) 99.9 66.4 1 to 30 years Total 1,156.2 1,058.8 Less: Accumulated depreciation 588.3 514.9 Net property and equipment $ 567.9 543.9 (1) Other includes certain assets, such as land, which are not depreciated. |
| Goodwill and Intangible Assets, Policy [Policy Text Block] | Business Combinations, Goodwill and Other Intangible Assets We have historically grown, in part, through a series of acquisitions. Consistent with the services nature of the majority of businesses we have acquired, we have recognized significant goodwill and intangible assets resulting from these acquisitions. Intangible assets are initially recorded at their respective acquisition date fair values and amortized on a straight-line basis over their estimated useful lives. They primarily represent management contracts and customer backlogs acquired as part of our acquisitions. We evaluate goodwill for impairment at least annually. We define our four reporting units as the three geographic regions of RES: (i) Americas, (ii) Europe, Middle East and Africa ("EMEA") and (iii) Asia Pacific; and (iv) LaSalle. We have considered qualitative and quantitative factors while performing our annual impairment test of goodwill and determined it is not more-likely-than-not that the fair value of all our reporting units are less than their respective carrying values. In performing our assessments, we primarily considered (i) macroeconomic and industry trends, (ii) our overall financial performance, and nature of the key drivers thereof, during the year at both the reporting unit and consolidated reporting levels, (iii) near and longer-term forecasts of operating income and cash flows generated by our reporting units in relation to the carrying values of the net assets of each reporting unit and (iv) our market capitalization in relation to the aggregate carrying value of our net assets. In addition to our annual impairment evaluation, we evaluated whether events or circumstances have occurred in the period subsequent to our annual impairment testing and determined it is not more-likely-than-not that the fair value of all our reporting units are less than their respective carrying values. It is possible our determination that goodwill for a reporting unit is not impaired could change in the future if current economic conditions deteriorate. We will continue to monitor the relationship between our market capitalization and carrying value, as well as the ability of our reporting units to deliver current and projected earnings and cash flows sufficient to support the carrying values of the net assets of their respective businesses. We evaluate our Identified intangibles for impairment annually or more frequently if other events or circumstances indicate the carrying value may be impaired. See Note 4, Business Combinations, Goodwill and Other Intangibles , for additional information on business combinations, goodwill and other intangible assets. |
| Equity Method Investments [Policy Text Block] | Investments in Real Estate Ventures We invest in certain ventures that primarily own and operate commercial real estate on a global basis across a wide array of sectors including retail, residential and office. Historically, these investments have primarily been co-investments in funds our LaSalle business establishes in the ordinary course of business for its clients. These investments take the form of equity ownership interests generally ranging from less than 1% to 10% of the respective ventures and, based upon investment-specific objectives, have generally included five to nine-year investment periods. Typically, our investments in real estate ventures are not redeemable until the earlier of the disposition of the underlying real estate investments or the end of the fund's life. When in place, such restrictions are a result of our role beyond that of a passive investor, which generally means an advisory or management responsibility on behalf of the other investors who are typically clients of our LaSalle business. We primarily account for these investments at fair value utilizing information provided by investees, however, as further discussed below, we report certain of our investments under the equity method. For real estate limited partnerships in which we are a general partner, the entities are generally well-capitalized and grant the limited partners substantive participating rights, such as the right to replace the general partner without cause, to dissolve or liquidate the partnership, to approve the sale or refinancing of the principal partnership assets, or to approve the acquisition of principal partnership assets. We account for such general partner interests at fair value or under the equity method. For limited partnerships in which we are a limited partner, management has concluded we do not have a controlling interest in these limited partnerships. When we have an asset advisory contract with the limited partnership, the combination of our limited partner interest and the advisory agreement generally provides us with significant influence over the real estate limited partnership venture. Accordingly, we account for such investments at fair value or under the equity method. For investments in real estate ventures reported at fair value, we maintain an investment account that is increased or decreased each reporting period by the difference between the fair value of the investment and the carrying value as of the balance sheet date. These fair value adjustments are reflected as gains or losses on the Consolidated Statements of Comprehensive Income within Equity earnings from real estate ventures. The fair value of these investments as of the balance sheet date is generally determined using net asset value ("NAV") per share (or its equivalent), an unobservable input in the fair value hierarchy, provided by the investee. See "Principles of Consolidation" above for additional discussion of the accounting for our co-investments. For investments in real estate ventures accounted for under the equity method, we maintain an investment account that is (i) increased by contributions made and by our share of net income earned by the real estate ventures, and (ii) decreased by distributions received and by our share of net losses realized by the real estate ventures. Our share of each real estate venture's net income or loss, including gains and losses from capital transactions, is reflected on the Consolidated Statements of Comprehensive Income as Equity earnings from real estate ventures. We evaluate our investments in real estate ventures accounted for under the equity method for other-than-temporary impairment on a quarterly basis, or as events or changes in circumstances warrant such an evaluation. Our evaluations consider the existence of impairment indicators in the underlying real estate assets that compose the majority of our investments. We base such evaluations, in regard to both the investment and the investment’s underlying asset levels, on regular updates to future cash flow models, our share of co-investment cash flows, and factors such as operational performance, market conditions, major tenancy matters, legal and environmental concerns, and our ability and intent to hold each investment. If an investment is considered other-than-temporarily impaired, we record the excess of the carrying value over the estimated fair value as an impairment charge. Impairment charges to write down the carrying value of the real estate assets underlying our investments are generally based on the result of discounted cash flow models that primarily rely upon unobservable inputs to determine fair value. We recognize our proportionate share of such impairment within Equity earnings from real estate ventures on the Consolidated Statements of Comprehensive Income. See Notes 5 and 9 for additional information on Investments in real estate ventures. |
| Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] | Stock-Based Compensation Stock-based compensation in the form of restricted stock units ("RSUs") and performance stock units ("PSUs") are an important element of our compensation programs. We determine the fair value of RSUs, subject only to service requirements, based on the closing market price of our common stock on the grant date. PSUs are subject to service requirements and one or more performance measures, including (i) performance conditions (e.g. achievement against earnings per share targets) and (ii) for certain awards, a market condition (e.g. total shareholder return performance against a peer group). We determine the fair value of PSUs based on the closing market price of our common stock on the grant date taking into consideration the likelihood of achieving each performance condition and the market condition valuation, as applicable, based on the output of Monte Carlo simulations. Employees of a specific age, with a sum of age plus years of service with the Company which meets or exceeds 65 , based on the terms of the Jones Lang LaSalle 2017 Stock Award and Incentive Plan ("SAIP"), are eligible to be considered for receipt of retirement benefits upon departure from the Company. These award provisions trigger application of certain elements of ASC Topic 718, Compensation - Stock Compensation , whereby the recognition of compensation expense for restricted stock unit awards granted to employees meeting the age plus service criteria is accelerated such that all expense is recognized by the time these employees are considered retirement eligible. We also have a "noncompensatory" Employee Stock Purchase Plan ("ESPP") for U.S. employees and a Jones Lang LaSalle Savings Related Share Option Plan ("Save As You Earn" or "SAYE") for U.K. employees. The fair value of options granted under the SAYE plan are determined on the grant date and amortized over the associated vesting period. See Note 6, Share-Based Compensation , for additional information on our stock-based compensation plans. |
| Income Tax, Policy [Policy Text Block] | Income Taxes We account for income taxes under the asset and liability method. We recognize deferred tax assets and liabilities for the expected future tax consequences of events that have been included in our financial statements or tax returns. Under this method, we determine deferred tax assets and liabilities based on the differences between the financial reporting and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. An increase or decrease in a deferred tax asset or liability that results from a change in circumstances, and that causes a change in our judgment about expected future tax consequences of events, would be included in the tax provision when the changes in circumstances and our judgment occurs. Deferred income taxes also reflect the impact of operating loss and tax credit carryforwards. A valuation allowance is established if we believe it is more-likely-than-not all or some portion of a deferred tax asset will not be realized. An increase or decrease in a valuation allowance that results from a change in circumstances, and that causes a change in our judgment about the ability to realize the related deferred tax asset, would be included in the tax provision when the changes in circumstances and our judgment occurs. See Note 8, Income Taxes , for additional information on income taxes. |
| Derivatives, Policy [Policy Text Block] | Derivatives and Hedging Activities We do not enter into derivative financial instruments for trading or speculative purposes. However, in the normal course of business, we do use derivative financial instruments in the form of foreign currency forward contracts to manage our foreign currency exchange rate risk. We currently do not use hedge accounting for these contracts, which are marked-to-market each period with changes in unrealized gains or losses recognized in earnings and offset by foreign currency gains and losses on associated intercompany loans and other foreign currency balances. Gains and losses from the revaluation of these contracts are recognized as a component of Operating, administrative and other expense and are offset by the gains and losses recognized on the revaluation of intercompany loans and other foreign currency balances such that the impact to net income was not significant for the three years ended December 31, 2018 . For presentation and disclosure, we net our exposure by counterparty for all counterparties subject to International Swaps and Derivatives Association Master Agreements. We have considered the counterparty credit risk related to these forward foreign currency exchange contracts and do not deem any counterparty credit risk to be material as of December 31, 2018 , in part due to the short-term nature of these contracts. In addition, certain loan commitments and forward sales commitments related to our Warehouse receivables meet the definition of a derivative and are recorded at fair value on the Consolidated Balance Sheets. The estimated fair value of loan commitments includes the fair value of the expected net cash flows associated with servicing of the loan, other net cash flows associated with origination and sale of the loan, and the effects of market interest rate movements. The estimated fair value of forward sale commitments includes the effects of market interest rate movements. Therefore, the effect of market interest rate movements on estimated fair value offset between the loan commitments and the forward sale commitments. Adjustments to fair value related to loan and forward sale commitments are included within Revenue on the Consolidated Statements of Comprehensive Income. See Note 9, Fair Value Measurements , for additional information on derivative financial instruments. |
| Foreign Currency Transactions and Translations Policy [Policy Text Block] | Foreign Currency Translation We prepare the financial statements of our subsidiaries located outside the U.S. using local currency as the functional currency. The assets and liabilities of these subsidiaries are translated to U.S. dollars at the rates of exchange as of the balance sheet date with the resulting translation adjustments included as a separate component of equity on the Consolidated Balance Sheets (Accumulated other comprehensive loss) and on the Consolidated Statements of Comprehensive Income (Other comprehensive income-foreign currency translation adjustments). See Note 15, Accumulated Other Comprehensive Income (Loss) , for additional information on the components of Accumulated other comprehensive loss. Income and expenses are translated at the average monthly rates of exchange. We include gains and losses from foreign currency transactions in net earnings as a component of Operating, administrative and other expense. For the years ended December 31, 2018 and 2017, we had net foreign currency losses of $4.1 million and $4.8 million , respectively. For the year ended December 31, 2016, we had a net foreign currency gain of $6.2 million . The effect of foreign currency exchange rate changes on Cash and cash equivalents is presented as a separate caption in the Consolidated Statements of Cash Flows. |
| Cash Held for Others [Policy Text Block] | Cash Held for Others We manage significant amounts of cash and cash equivalents in our role as agent for certain of our investment, facility management and property management clients. We do not include such amounts on the Consolidated Balance Sheets. |
| Taxes Collected from Clients and Remitted to Governmental Authorities [Policy Text Block] | Taxes Collected from Clients and Remitted to Governmental Authorities We account for tax assessed by a governmental authority that is based on a revenue or transaction value (i.e., sales, use and value-added taxes) on a net basis, excluded from revenue, and recorded as current liabilities until paid. |
| Commitments and Contingencies, Policy [Policy Text Block] | Commitments and Contingencies We are subject to various claims and contingencies related to disputes, lawsuits and taxes as well as commitments under contractual obligations. Many of these claims are covered under our current insurance programs, subject to deductibles. We recognize the liability associated with a loss contingency when a loss is probable and estimable. See Note 13, Commitments and Contingencies , for additional information on commitments and contingencies. |
| Earnings Per Share, Policy [Policy Text Block] | Earnings Per Share; Net Income Available to Common Shareholders The difference between basic weighted average shares outstanding and diluted weighted average shares outstanding represents the dilutive impact of our common stock equivalents. Common stock equivalents consist of shares to be issued under employee stock-based compensation programs. Anti-dilutive shares were de minimus for all periods presented. See Note 6, Share-Based Compensation , for additional information on our stock-based compensation plans. |
| New Accounting Pronouncements, Policy [Policy Text Block] | New Accounting Standards Recently adopted accounting guidance Effective January 1, 2018, we adopted Accounting Standards Update ("ASU") No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost , which requires an employer to disaggregate the employer service cost component from the other components of net periodic pension cost. The primary impact for JLL is the requirement to present the components of net periodic pension cost that do not represent the employer service cost outside of the subtotal "Operating income" on the Consolidated Statements of Comprehensive Income. As full retrospective application is required, we recast our comparative information, reclassifying the components of net periodic pension cost, other than the employer service cost component, from Compensation and benefits expense to Other income on the Consolidated Statements of Comprehensive Income. For the years ended December 31, 2017 and 2016, the amounts reclassified were benefits of $1.7 million and $6.3 million , respectively. The adoption of ASU 2017-07 had no impact on our Consolidated Balance Sheets or Consolidated Statements of Cash Flows. Refer to the table below for the impact of adopting this ASU on our comparative Consolidated Statement of Comprehensive Income. Effective January 1, 2018, we adopted ASU No. 2016-18, Restricted Cash , which addresses classification and presentation of changes in restricted cash on the statement of cash flows. Specifically, this ASU requires a statement of cash flows to explain the changes during the period in cash, cash equivalents, and amounts reported as restricted cash or restricted cash equivalents. The primary effect of the adoption was the inclusion of restricted cash along with cash and cash equivalents in reconciling the beginning and ending total amounts shown on the Consolidated Statements of Cash Flows. We adopted this ASU on a full retrospective basis. Restricted cash is included in Prepaid and other current assets on the Consolidated Balance Sheets. In May 2014, the Financial Accounting Standards Board ("FASB") issued ASU No. 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers; in March 2016, the FASB issued ASU No. 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net) , which clarifies the implementation guidance on principal versus agent considerations and together with ASU No. 2014-09 (collectively the "ASUs"), amends and comprises ASC Topic 606. These ASUs, and other related ASUs, replaced most existing revenue recognition guidance in U.S. generally accepted accounting principles ("U.S. GAAP"). Effective January 1, 2018, we adopted ASC Topic 606 on a full retrospective basis. The adoption of ASC Topic 606 resulted in an acceleration of the timing of revenue recognition for certain brokerage-related transaction commissions and advisory services. These items include variable consideration or other aspects, such as contingencies, that precluded revenue recognition contemporaneous with the satisfaction of our performance obligations within the previous revenue recognition framework. The acceleration of the timing of revenue recognition also resulted in the acceleration of expense recognition relating to direct commissions expense payable to brokers. Implementation of the updated principal versus agent considerations in ASC Topic 606 resulted in a significant increase to the proportion of our Property & Facility Management and Project & Development Services contracts presented on a gross basis (hereafter “gross contracts”). Under the previous principal versus agent framework, our evaluations for presentation of a service contract contemplated both performance and payment risk. Contractual provisions with clients and third-party vendors and subcontractors, such as “pay-when-paid”, that substantially mitigate our payment risk with respect to on-site personnel and other expenses incurred on our clients’ behalf have historically resulted in the majority of our service contracts being presented on a net basis. However, within ASC Topic 606, payment risk is not an evaluation factor; instead, control of the service before transfer to the customer is the focal point of current principal versus agent assessments. As a result, we determined that costs associated with all client-dedicated JLL personnel, even when directly reimbursed by clients, and arrangements where we control the services provided by a third-party prior to the transfer to the customer will now be presented on a gross basis. The incremental expenses and corresponding revenue recognized as a result of the adoption of the new principal versus agent framework are presented in new financial statement captions, Reimbursed expenses and Reimbursements, respectively, in our Consolidated Statements of Comprehensive Income. We have reclassified reimbursable activity in our comparative financial statements. Finally, the adoption of ASC Topic 606 resulted in a material increase to total assets and total liabilities to reflect (i) contract assets and accrued commissions payable recognized upon acceleration of the timing of revenue recognition for certain transactions commissions and advisory services and (ii) assets and liabilities relating to service contracts now reported on a gross basis. Balance sheet activity associated with contracts now reported on a gross basis is most prominently reflected within Reimbursable receivables and Reimbursable payables, new financial statement captions established in conjunction with our adoption of ASC Topic 606. We have reclassified reimbursable balances in our comparative financial statements. The impact of adopting new accounting pronouncements on a retrospective basis to the Consolidated Balance Sheet as of December 31, 2017, and Consolidated Statement of Comprehensive Income for the years ended December 31, 2017 and 2016, were as follows (for impacted financial statement captions): (in millions) Original Published December 31, 2017 Adjustment due to ASC Topic 606 As Restated December 31, 2017 Assets Trade receivables, net of allowances (1) $ 2,118.1 (378.7 ) $ 1,739.4 Note and other receivables (1) 393.6 (8.3 ) 385.3 Reimbursable receivables n/a 1,263.3 1,263.3 Short-term contract assets n/a 178.4 178.4 Prepaid & other current assets (2) 257.7 131.4 389.1 Long-term receivables 168.6 (3.9 ) 164.7 Other assets 97.8 57.7 155.5 Liabilities and equity Accounts payable and accrued liabilities (1) $ 1,011.6 (18.5 ) $ 993.1 Reimbursable payables n/a 1,022.6 1,022.6 Accrued compensation & benefits 1,309.0 110.1 1,419.1 Short-term contract liabilities and deferred income (1) 158.9 (3.5 ) 155.4 Other current liabilities (1) 263.8 (7.0 ) 256.8 Deferred tax liabilities, net 23.9 39.3 63.2 Retained earnings 2,552.8 96.2 2,649.0 Accumulated other comprehensive (loss) income (341.8 ) 0.7 (341.1 ) (1) Adjustments in these captions reflect reclassifications to new financial statement captions, Reimbursable receivables and Reimbursable payables. (2) Adjustments in this caption reflect an increase to restricted cash held on behalf of clients for contracts now presented on a gross basis. (in millions) Original Published Adjustment due to ASC Topic 606 Adjustment due to ASU 2017-07 As Restated Revenue Revenue before reimbursements (1) $ 7,932.4 35.0 — $ 7,967.4 Reimbursements (1) n/a 6,485.8 — 6,485.8 Total revenue 7,932.4 6,520.8 — 14,453.2 Operating expenses Compensation and benefits (1) 4,572.2 48.5 1.7 4,622.4 Operating, administrative and other (1) 2,625.4 (24.2 ) — 2,601.2 Reimbursed expenses (1) n/a 6,485.8 — 6,485.8 Operating income 536.9 10.7 (1.7 ) 545.9 Other income — — 1.7 1.7 Provision for income taxes 267.8 (11.5 ) — 256.3 Net income 257.3 22.2 — 279.5 Basic earnings per common share $ 5.60 0.49 — $ 6.09 Diluted earnings per common share $ 5.55 0.48 — $ 6.03 (1) Included in "Adjustments due to ASC Topic 606" is $56.8 million representing the reclassification of historical reimbursed expenses and the corresponding reimbursement revenue into new financial statement captions, Reimbursements and Reimbursed expenses. (in millions) Original Published Adjustment due to ASC Topic 606 Adjustment due to ASU 2017-07 As Restated Revenue Revenue before reimbursements (1) $ 6,803.8 106.8 — $ 6,910.6 Reimbursements (1) n/a 6,080.6 — 6,080.6 Total revenue 6,803.8 6,187.4 — 12,991.2 Operating expenses Compensation and benefits (1) 3,983.1 51.1 6.3 4,040.5 Operating, administrative and other (1) 2,169.8 34.3 — 2,204.1 Reimbursed expenses (1) n/a 6,080.6 — 6,080.6 Operating income 440.6 21.4 (6.3 ) 455.7 Other income 13.3 (0.1 ) 6.3 19.5 Provision for income taxes 108.0 9.8 — 117.8 Net income 334.4 11.5 — 345.9 Basic earnings per common share $ 7.04 0.25 — $ 7.29 Diluted earnings per common share $ 6.98 0.25 — $ 7.23 (1) Included in "Adjustments due to ASC Topic 606" is $60.2 million representing the reclassification of historical reimbursed expenses and the corresponding reimbursement revenue into new financial statement captions, Reimbursements and Reimbursed expenses. The cumulative impact to our retained earnings and Consolidated Statement of Comprehensive Income includes certain direct expenses, such as accrued commissions and deferred income taxes, resulting from the changes in accounting principle in accordance with ASC Topic 250, which partially offset the impact of the acceleration of revenue. Refer to the Consolidated Statement of Changes in Equity for the cumulative impact to our retained earnings from the adoption of ASC Topic 606, as of January 1, 2016. Recently issued accounting guidance, not yet adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which increases transparency and comparability by requiring the recognition of lease assets and lease liabilities on the balance sheet as well as requiring the disclosure of key information about leasing arrangements. This ASU is effective for annual and interim periods beginning after December 15, 2018, with early adoption permitted. In July 2018, the FASB codified an alternative (and optional) transition method via ASU No. 2018-11, Leases (Topic 842): Targeted Improvements ; we will elect the use of this optional transition method. The adoption of ASC Topic 842 will result in the recognition of additional balances on the Consolidated Balance Sheet to reflect right-of-use assets and lease liabilities primarily associated with operating leases for the corporate real estate we occupy around the globe. The balance of our lease population comprises vehicle and other equipment leases. As of December 31, 2018, we have substantially completed the identification of our real estate and non-real estate leases population, compiled and calculated the relevant inputs to derive ASC Topic 842's impact, and are assessing the functionality of our selected technology to facilitate ongoing compliance and designing post-implementation processes and associated internal controls. We intend to elect certain practical expedients permitted under ASC Topic 842's transition guidance, such as the practical expedients to not reassess lease classification, lease term or initial direct costs for the existing lease portfolio, as well as to not separate lease and non-lease components. Based upon current evaluations, we expect to recognize additional assets and liabilities upon implementation of ASC Topic 842 ranging from $650 million to $700 million to reflect right-of-use assets and lease liabilities as of January 1, 2019. However, because our evaluations are ongoing, the expected impact associated with the implementation of ASC Topic 842 is subject to change. Our disclosures related to leases will expand to comply with the requirements of ASC Topic 842; we continue to evaluate other effects ASC Topic 842 will have on our financial statements and related disclosures. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) , which creates a new framework to evaluate financial instruments, such as trade receivables, for expected credit losses. This new framework replaces the existing incurred loss approach and is expected to result in more timely recognition of credit losses. ASU No. 2016-13 is effective for annual and interim periods beginning after December 15, 2019 and early adoption is not permitted until years beginning after December 15, 2018. We are evaluating the effect this guidance will have on our financial statements and related disclosures. In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment , which eliminates Step 2 from the goodwill impairment test. The annual goodwill impairment test will require companies to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge when the carrying amount exceeds the fair value of the reporting unit. This ASU is effective for annual and interim goodwill impairment tests beginning after December 15, 2019, with early adoption permitted. We do not believe this guidance will have a material impact on our financial statements and related disclosures. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820) Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement , which updates the disclosure requirements in Topic 820 by removing, adding and modifying certain disclosure requirements for fair value measurements. This ASU is effective for annual and interim periods beginning after December 15, 2019, with early adoption permitted. In addition, entities have the option to partially adopt ASU No. 2018-13 with respect to any subset of removed or modified disclosures and defer the adoption of additive disclosures and any remaining disclosures not early adopted. In the fourth quarter of 2018, we adopted the portion of the ASU No. 2018-13 relating to eliminated disclosure requirements, but deferred the adoption of modified and additive disclosure requirements; we expect the remaining aspects of this ASU will not have a material impact on our fair value disclosures. In August 2018, the FASB issued ASU No. 2018-15, Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract , which requires a customer in a cloud computing arrangement that is a service contract to follow the internal-use software guidance in ASC 350-40 when determining which implementation costs to capitalize as intangible assets. This ASU is effective for annual and interim periods beginning after December 15, 2019, with early adoption permitted. We do not believe this guidance will have a material impact on our financial statements and related disclosures. |
