The Interpublic Group of Companies, Inc. (IPG) 10-K 21 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 13, 2020	Jun. 28, 2019
DEI [Abstract]
Document Annual Report	true
Document Information [Line Items]
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	1-6686
Entity Registrant Name	INTERPUBLIC GROUP OF COMPANIES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-1024020
Entity Address, Address Line One	909 Third Avenue,
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10022
City Area Code	(212)
Local Phone Number	704-1200
Title of 12(b) Security	Common Stock, par value $0.10 per share
Trading Symbol	IPG
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		387,824,443
Entity Central Index Key	0000051644
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Public Float			$ 8,700,000,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net revenue	$ 2,433	$ 2,061.4	$ 2,125.9	$ 2,004.8	$ 2,413.7	$ 1,895.7	$ 1,948.2	$ 1,774	$ 8,625.1	$ 8,031.6	$ 7,473.5
Billable expenses	468.8	376.7	394.3	356.4	442.3	401.8	443.6	395.1	1,596.2	1,682.8	1,574.1
Total revenue	2,901.8	2,438.1	2,520.2	2,361.2	2,856	2,297.5	2,391.8	2,169.1	10,221.3	9,714.4	9,047.6
OPERATING EXPENSES:
Salaries and related expenses	1,432.1	1,334.4	1,381.2	1,421.1	1,423.7	1,251.4	1,292.9	1,330.3	5,568.8	5,298.3	4,990.7
Office and other direct expenses	419.7	367.9	387.3	389.2	381	317	333.3	323.8	1,564.1	1,355.1	1,269.2
Billable expense	468.8	376.7	394.3	356.4	442.3	401.8	443.6	395.1	1,596.2	1,682.8	1,574.1
Cost of services	2,320.6	2,079	2,162.8	2,166.7	2,247	1,970.2	2,069.8	2,049.2	8,729.1	8,336.2	7,834
Selling, General and Administrative Expense	24.5	9.8	18.1	41.4	81	21.6	28.8	35.1	93.8	166.5	118.5
Depreciation and amortization	65.4	69	73	71.1	68.9	44	44	46	278.5	202.9	157.1
Restructuring Charges	0	0	2.1	31.8	0	0	0	0	33.9	0	(0.4)
Total operating expenses	2,410.5	2,157.8	2,256	2,311	2,396.9	2,035.8	2,142.6	2,130.3	9,135.3	8,705.6	8,109.2
OPERATING INCOME	491.3	280.3	264.2	50.2	459.1	261.7	249.2	38.8	1,086	1,008.8	938.4
EXPENSES AND OTHER INCOME:
Interest expense									(199.3)	(123)	(90.8)
Interest income									34.5	21.8	19.4
Other expense, net	(24.8)	(7.4)	(3.8)	(6.9)	(13.6)	(15.3)	(16.3)	(24.4)	(42.9)	(69.6)	(26.2)
Total (expenses) and other income	(63.5)	(47.6)	(47.7)	(48.9)	(55.2)	(37.6)	(37.7)	(40.3)	(207.7)	(170.8)	(97.6)
Income before income taxes									878.3	838	840.8
Provision for income taxes	86.1	64.6	43.6	10.5	62.2	60.7	63.6	12.7	204.8	199.2	271.3
Income of consolidated companies									673.5	638.8	569.5
Equity in net (loss) income of unconsolidated affiliates									0.4	(1.1)	0.9
NET INCOME	$ 342.2	$ 168.4	$ 172.8	$ (9.5)	$ 342.5	$ 163.5	$ 147.8	$ (16.1)	673.9	637.7	570.4
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest									(17.9)	(18.8)	(16)
Net Income (Loss) Attributable to Parent									$ 656	$ 618.9	$ 554.4
Earnings per share available to IPG common stockholders:
Earnings per share, Basic	$ 0.85	$ 0.43	$ 0.44	$ (0.02)	$ 0.85	$ 0.42	$ 0.38	$ (0.04)	$ 1.70	$ 1.61	$ 1.42
Earnings per share, Diluted	$ 0.84	$ 0.42	$ 0.43	$ (0.02)	$ 0.84	$ 0.41	$ 0.37	$ (0.04)	$ 1.68	$ 1.59	$ 1.40
Weighted-average number of common shares outstanding:
Weighted-average number of common shares outstanding, Basic									386.1	383.3	389.6
Weighted-average number of common shares outstanding, Diluted									391.2	389	397.3

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 673.9	$ 637.7	$ 570.4
Foreign Currency Translation:
Foreign currency translation adjustments	11.3	(149.6)	133.7
Reclassification adjustments recognized in net income	6.7	15.7	1.1
Foreign currency translation, net of tax	18	(133.9)	134.8
Available-for-sale securities:
Changes in fair value of available-for-sale securities	0	0	0
Recognition of previously unrealized gains in net income	0	0	(0.7)
Income tax effect	0	0	0.1
Available-for-sale securities, net of tax	0	0	(0.6)
Derivatives instruments:
Recognition of previously unrealized losses included in net income	2.3	2.2	2.1
Income tax effect	(0.5)	(0.7)	(0.5)
Derivative instruments, net of tax	1.8	1.5	1.6
Defined benefit pension and other postretirement plans:
Net actuarial (losses) gains for the period	(14.8)	12.6	(13.6)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax	6.7	7.5	6.9
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	0	(1)	6.8
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Other, before Tax	(2.5)	(1)	2.7
Income tax effect	1.2	(1.8)	(0.5)
Defined benefit pension and other postretirement plans, net of tax	(9.4)	16.3	2.3
Other comprehensive income (loss), net of tax	10.4	(116.1)	138.1
Total comprehensive income	684.3	521.6	708.5
Less: comprehensive income attributable to noncontrolling interests	17.2	16	17.5
Comprehensive Income Attributable to IPG	$ 667.1	$ 505.6	$ 691

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS:
Cash and cash equivalents	$ 1,192.2		$ 673.4
Accounts receivable, net of allowance of $40.2 and $42.5, respectively	5,209.2		5,126.6
Accounts receivable, billable to clients	1,934.1		1,900.6
Assets held for sale	22.8		5.7
Other current assets	412.4		476.6
Total current assets	8,770.7		8,182.9
Property and equipment, net of accumulated depreciation of $1,116.4 and $1,034.9, respectively	778.1		790.9
Deferred income taxes	252.1		247
Goodwill	4,894.4		4,875.9	$ 3,820.4
Other intangible assets	1,014.3		1,094.7
Operating Lease, Right-of-Use Asset	1,574.4	$ 1,421.1	0
Other non-current assets	467.9		428.9
TOTAL ASSETS	17,751.9		15,620.3
LIABILITIES:
Accounts payable	7,205.4		6,698.1
Accrued liabilities	742.8		806.9
Contract liabilities	585.6		533.9
Short-term borrowings	52.4		73.7
Current portion of long-term debt	502		0.1
Operating Lease, Liability, Current	267.2		0
Liabilities held for sale	65		11.2
Total current liabilities	9,420.4		8,123.9
Long-term debt	2,771.9		3,660.2
Operating Lease, Liability, Noncurrent	1,429.6		0
Deferred compensation	425		422.7
Other non-current liabilities	714.7		812.8
TOTAL LIABILITIES	14,761.6		13,019.6
Redeemable noncontrolling interests	164.7		167.9	252.1	$ 252.8
STOCKHOLDERS' EQUITY:
Common stock, $0.10 par value, shares authorized: 800.0 shares issued: 2019 - 387.0; 2018 - 383.6 shares outstanding: 2019 - 387.0; 2018 - 383.6	38.7		38.3
Additional paid-in capital	977.3		895.9
Retained earnings	2,689.9		2,400.1
Accumulated other comprehensive loss, net of tax	(930)		(941.1)	(827.8)
Total IPG stockholders' equity	2,775.9		2,393.2
Noncontrolling interests	49.7		39.6
TOTAL STOCKHOLDERS' EQUITY	2,825.6		2,432.8	$ 2,246.3	$ 2,090.4
TOTAL LIABILITIES AND EQUITY	$ 17,751.9		$ 15,620.3

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 40.2	$ 42.5
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ 1,116.4	$ 1,034.9
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	800	800
Common stock, shares issued	387	383.6
Common stock, shares outstanding	387	383.6
Treasury stock, shares	0	0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	$ 673.9	$ 637.7	$ 570.4
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	278.5	202.9	157.1
Provision for uncollectible receivables	10.1	6.5	9.5
Amortization of restricted stock and other non-cash compensation	80.2	82.2	82
Net amortization of bond discounts and deferred financing costs	9.3	6.5	5.8
Deferred income tax provision	9.7	14.1	(9.5)
Net losses on sales of businesses	43.4	61.9	24.1
Other	9.9	1.2	12.7
Changes in assets and liabilities, net of acquisitions and divestitures, providing (using) cash:
Accounts receivable	(111.2)	(603.8)	37.6
Accounts receivable, billable to clients	(38.7)	(209.5)	(165.5)
Other current assets	(27.2)	(67.2)	50.1
Accounts payable	546	428.7	336.4
Accrued liabilities	27.4	(24.2)	(241.3)
Contract liabilities	46.5	44.9	(12)
Change in operating lease right-of-use asset and lease liabilities	0.7	0	0
Other non-current assets and liabilities	(29.3)	(16.8)	24.4
Net cash provided by operating activities	1,529.2	565.1	881.8
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions, net of cash acquired	0.6	2,309.8	30.6
Capital expenditures	198.5	177.1	155.9
Other investing activities	37.4	(4.6)	(9.7)
Net cash used in investing activities	(161.7)	(2,491.5)	(196.2)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Issuance of Long-term Debt	0	2,494.2	0
Exercise of stock options	4.3	15.5	13.1
Common stock dividends	(363.1)	(322.1)	(280.3)
Repurchases of common stock	0	(117.1)	(300.1)
Repayments of long-term debt	(403.3)	(104.8)	(324.6)
Acquisition-related payments	(15.8)	(33.7)	(53.7)
Tax payments for employee shares withheld	(22.4)	(29.2)	(38.8)
Net (decrease) increase in short-term borrowings	(19.8)	(17.5)	3
Distributions to noncontrolling interests	(21.6)	(16.9)	(20.4)
Other financing activities	(1.3)	(15.2)	(3.1)
Net cash (used in) provided by financing activities	(843)	1,853.2	(1,004.9)
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	(6)	(47.3)	16.8
Net increase (decrease) in cash, cash equivalents and restricted cash	518.5	(120.5)	(302.5)
Cash, cash equivalents and restricted cash at beginning of period	677.2	797.7	1,100.2
Cash, cash equivalents and restricted cash at end of period	$ 1,195.7	$ 677.2	$ 797.7

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock, Shares Issued [Member]	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss, Net of Tax	Treasury Stock	Total IPG Stockholders' Equity	Noncontrolling Interests
Common stock, shares issued		394.3
Balance at Dec. 31, 2016	$ 2,090.4		$ 39.4	$ 1,199.2	$ 1,839.9	$ (964.4)	$ (63.3)	$ 2,050.8	$ 39.6
Cumulative effect of accounting change	570.4
Net Income (Loss) Attributable to Parent	554.4
NET INCOME	570.4				554.4			554.4
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	16								16
Other comprehensive income	138.1					136.6		136.6	1.5
Reclassifications related to redeemable noncontrolling interests	0.6			(0.3)				(0.3)	0.9
Distributions to noncontrolling interests	(20.9)								(20.9)
Change in redemption value of RNCI	(7.9)				(7.9)			(7.9)
Repurchases of common stock	(300.1)						(300.1)	300.1
Retirement of treasury stock, shares			(13.4)
Retirement of treasury stock	0		$ (1.3)	(303.1)			(304.4)	0
Common stock dividends	(280.3)				(280.3)			(280.3)
Stock-based compensation, shares			5.7
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	87		$ 0.6	86.4				87
Exercise of stock options, shares			1.2
Exercise of stock options, Value	13.2		$ 0.1	13.1				13.2
Shares withheld for taxes, shares			(1.6)
Shares withheld for taxes, value	39		$ 0.2	38.8				39
Other	(5.2)			1.3	(1.6)			(2.9)	(2.3)
Balance at Dec. 31, 2017	2,246.3		$ 38.6	955.2	2,104.5	(827.8)	(59)	2,211.5	34.8
Common stock, shares issued		386.2
Net Income (Loss) Attributable to Parent	618.9
NET INCOME	637.7				618.9			618.9
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	18.8								18.8
Other comprehensive income	(116.1)					(113.3)		(113.3)	(2.8)
Reclassifications related to redeemable noncontrolling interests	2.4							0	2.4
Distributions to noncontrolling interests	(16.9)								(16.9)
Change in redemption value of RNCI	42.9			41.8	1.1			42.9
Repurchases of common stock	(117.1)						(117.1)	(117.1)
Retirement of treasury stock, shares			(8.1)
Retirement of treasury stock	0		$ (0.8)	(175.3)			(176.1)	0
Common stock dividends	(322.1)				(322.1)			(322.1)
Stock-based compensation, shares			4.8
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	87.5		$ 0.5	87				87.5
Exercise of stock options, shares			1.9
Exercise of stock options, Value	15.7		$ 0.2	15.5				15.7
Shares withheld for taxes, shares			(1.2)
Shares withheld for taxes, value	29.2		$ 0.2	29				29.2
Other	1.7			(0.7)	(2.3)			(1.6)	3.3
Balance at Dec. 31, 2018	$ 2,432.8		38.3	895.9	2,400.1	(941.1)	$ 0	2,393.2	39.6
Common stock, shares issued	383.6	383.6
Cumulative effect of accounting change	$ 1.2				1.2			1.2
Net Income (Loss) Attributable to Parent	656				656			656
NET INCOME	673.9
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	17.9								17.9
Other comprehensive income	10.4					11.1		11.1
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest									(0.7)
Reclassifications related to redeemable noncontrolling interests	24.6			11.9				11.9	12.7
Distributions to noncontrolling interests	(21.6)								21.6
Change in redemption value of RNCI	(0.2)				(0.2)			(0.2)
Common stock dividends	(363.1)				(363.1)			(363.1)
Stock-based compensation, shares		3.8
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	89.1		0.4	88.7				89.1
Exercise of stock options, shares		0.6
Exercise of stock options, Value	4.3		0.1	4.2				4.3
Shares withheld for taxes, shares		(1)
Shares withheld for taxes, value	22.4		(0.1)	(22.3)				(22.4)
Other	3.4			1.1	4.1			5.2	(1.8)
Balance at Dec. 31, 2019	$ 2,825.6		$ 38.7	$ 977.3	$ 2,689.9	$ (930)		$ 2,775.9	$ 49.7
Common stock, shares issued	387	387

Significant Accounting Policies

Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Business Description The Interpublic Group of Companies, Inc. and subsidiaries (the “Company,” “IPG,” “we,” “us” or “our”) is one of the world’s premier global advertising and marketing services companies. Our agencies create customized marketing programs for clients that range in scale from large global marketers to regional and local clients. Comprehensive global services are critical to effectively serve our multinational and local clients in markets throughout the world, as they seek to build brands, increase sales of their products and services and gain market share. Principles of Consolidation The Consolidated Financial Statements include the accounts of the Company and its consolidated subsidiaries, some of which are not wholly owned. Investments in companies over which we do not have control, but have the ability to exercise significant influence, are accounted for using the equity method of accounting. Investments in companies over which we have neither control nor have the ability to exercise significant influence are recorded at cost, less any impairment, adjusted for subsequent observable price changes. All intercompany accounts and transactions have been eliminated in consolidation. We have consolidated certain entities meeting the definition of variable interest entities, and the inclusion of these entities does not have a material impact on our Consolidated Financial Statements. Basis of Presentation Cost of services is comprised of the expenses of our revenue-producing operating segments including salaries and related expenses, office and other direct expenses and billable expenses, as well as an allocation of the centrally managed expenses from Corporate. Office and other direct expenses include rent expense, professional fees, certain expenses incurred by our staff in servicing our clients and other costs directly attributable to client engagements. Selling, general and administrative expenses are primarily the unallocated expenses from Corporate, as disclosed further in Note 15 , excluding depreciation and amortization. Depreciation and amortization of the fixed assets and intangible assets of the Company is disclosed as a separate operating expense. Restructuring charges relate to the Company's implementation of a cost initiative to better align our cost structure with our revenue, as discussed further in Note 11 . Reclassifications Certain reclassifications and immaterial revisions have been made to prior-period financial statements to conform to the current-period presentation. Segment information for the prior period has been recast to conform to the current-period presentation. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires us to make judgments, assumptions and estimates that affect the amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the reporting date and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and assumptions. Revenue Recognition Our revenues are primarily derived from the planning and execution of multi-channel advertising and communications, marketing services, including public relations, meeting and event production, sports and entertainment marketing, corporate and brand identity, strategic marketing consulting, and providing marketing data and technology services around the world. Most of our client contracts are individually negotiated and, accordingly, the terms of client engagements and the basis on which we earn fees and commissions vary significantly. Our contracts generally provide for termination by either party on relatively short notice, usually 30 to 90 days, although our data management contracts typically have non-cancelable terms of more than one year. Our payment terms vary by client, and the time between invoicing date and due date is typically not significant. We generally have the legally enforceable right to payment for all services provided through the end of the contract or termination date. We recognize revenue when we determine our customer obtains control of promised goods or services, in an amount that reflects the consideration which we expect to receive in exchange for those goods or services. To determine revenue recognition, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue as or when we satisfy the performance obligation. We only apply the five-step model to contracts when it is probable that IPG will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, we assess the goods or services promised within each contract and determine those that are distinct performance obligations. We then assess whether we act as an agent or a principal for each identified performance obligation and include revenue within the transaction price for third-party costs when we determine that we act as principal. We typically do not capitalize costs to obtain a contract as these amounts would generally be recognized over a period of one year or less. Net revenue, primarily consisting of fees, commissions and performance incentives, represents the amount of our gross billings excluding billable expenses charged to a client. Generally, our compensation is based on a negotiated fixed price, rate per hour, a retainer, commission or volume. The majority of our fees are recognized over time as services are performed, either utilizing a function of hours incurred and rates per hour, as compared to periodically updated estimates to complete, or ratably over the term of the contract. For certain less-frequent commission-based contracts which contain clauses allowing our clients to terminate the arrangement at any time for no compensation, revenue is recognized at a point in time, typically the date of broadcast or publication. We report revenue net of taxes assessed by governmental authorities that are directly imposed on our revenue-producing transactions. Contractual arrangements with clients may also include performance incentive provisions designed to link a portion of our revenue to our performance relative to mutually agreed-upon qualitative and/or quantitative metrics. Performance incentives are treated as variable consideration which is estimated at contract inception and included in revenue based on the most likely amount earned out of a range of potential outcomes. Our estimates are based on a combination of historical award experience, anticipated performance and our best judgment. These estimates are updated on a periodic basis and are not expected to result in a reversal of a significant amount of the cumulative revenue recognized. The predominant component of billable expenses are third-party vendor costs incurred for performance obligations where we have determined that we are acting as principal. These third-party expenses are generally billed back to our clients. Billable expenses also includes incidental costs incurred in the performance of our services including airfare, mileage, hotel stays, out-of-town meals and telecommunication charges. We record these billable expenses within total revenue with a corresponding offset to operating expenses. In international markets, we may receive rebates or credits from vendors based on transactions entered into on behalf of clients. Rebates and credits are remitted back to our clients in accordance with our contractual requirements or may be retained by us based on the terms of a particular client contract and local law. Amounts owed back to clients are recorded as a liability and amounts retained by us are recorded as revenue when earned. In certain international markets, our media contracts may allow clients to terminate our arrangement at any time for no compensation to the extent that media has not yet run. For those contracts, we do not recognize revenue until the media runs which is the point in time at which we have a legally enforceable right to compensation. Performance Obligations Our client contracts may include various goods and services that are capable of being distinct, are distinct within the context of the contract and are therefore accounted for as separate performance obligations. We allocate revenue to each performance obligation in the contract at inception based on its relative standalone selling price. Our advertising businesses include a wide range of services that involve the creation of an advertising idea, concept, campaign, or marketing strategy in order to promote the client’s brand ("creative services"), and to act as an agent to facilitate the production of advertisements by third-party suppliers ("production services”). Our clients can contract us to perform one or both of these services, as they can derive stand-alone benefit from each. Production services can include formatting creative material for different media and communication mediums including digital, large-scale reproduction such as printing and adaptation services, talent engagement and acquisition, television and radio production, and outdoor billboard production. Our contracts that include both services are typically explicit in the description of which activities constitute the creative advertising services and those that constitute the production services. Both the creative and production services are sold separately, the client can derive utility from each service on its own, we do not provide a significant service of integrating these activities into a bundle, the services do not significantly modify one another, and the services are not highly interrelated or interdependent. As such, we typically identify two performance obligations in the assessment of our advertising contracts. Our media businesses include services to formulate strategic media plans ("media planning services") and to act as an agent to purchase media (e.g. television and radio spots, outdoor advertising, digital banners, etc.) from vendors on their behalf ("media buying services"). Our contracts that include both services are typically explicit in the description of which activities constitute the planning services and those that constitute the buying services. Both the planning and buying services are sold separately, the client can derive utility from each service on its own, we do not provide a significant service of integrating these activities into a bundle, the services do not significantly modify one another, and the services are not highly interrelated or interdependent. As such, we typically identify two performance obligations in the assessment of our media contracts. Our events businesses include creative services related to the conception and planning of custom marketing events as well as activation services which entail the carrying out of the event, including, but not limited to, set-up, design and staffing. Additionally, our public relations businesses include a broad range of services, such as strategic planning, social media strategy and the monitoring and development of communication strategies, among others. While our contracts in these businesses may include some or all of these services, we typically identify only one performance obligation in the assessment of our events and public relations contracts as we provide a significant service of integrating the individual services into a combined service for which the customer has contracted. Our data and technology services businesses include data management, data and data strategy, identity resolution, and measurement and analytics products and services. While our contracts in these businesses may include some or all of these services, we typically identify each product and service as an individual performance obligation. We have elected not to disclose information about remaining performance obligations that have original expected durations of one year or less. The majority of our contracts are for periods of one year or less with the exception of our data management contracts. Principal vs. Agent When a third-party is involved in the delivery of our services to the client, we assess whether or not we are acting as a principal or an agent in the arrangement. The assessment is based on whether we control the specified services at any time before they are transferred to the customer. We have determined that in our events and public relations businesses, we generally act as a principal as our agencies provide a significant service of integrating goods or services provided by third parties into the specified deliverable to our clients. In addition, we have determined that we are responsible for the performance of the third-party suppliers, which are combined with our own services, before transferring those services to the customer. In addition, we have determined that we act as principal when providing creative services and media planning services, as we perform a significant integration service in these transactions. For performance obligations in which we act as principal, we record the gross amount billed to the customer within total revenue and the related incremental direct costs incurred as billable expenses. When a third-party is involved in the production of an advertising campaign and for media buying services, we have determined that we act as the agent and are solely arranging for the third-party to provide services to the customer. Specifically, we do not control the specified services before transferring those services to the customer, we are not primarily responsible for the performance of the third-party services, nor can we redirect those services to fulfill any other contracts. We do not have inventory risk or discretion in establishing pricing in our contracts with customers. For performance obligations for which we act as the agent, we record our revenue as the net amount of our gross billings less amounts remitted to third parties. Cash and Cash Equivalents Cash equivalents are highly liquid investments, which include certificates of deposit, government securities, commercial paper and time deposits with original maturities of three months or less at the time of purchase and are stated at estimated fair value, which approximates cost. Cash is maintained at multiple high-credit-quality financial institutions. Allowance for Doubtful Accounts The allowance for doubtful accounts is estimated based on the aging of accounts receivable, reviews of client credit reports, industry trends and economic indicators, as well as reviews of recent payment history for specific customers. The estimate is based largely on a formula-driven calculation but is supplemented with economic indicators and knowledge of potential write-offs of specific client accounts. Accounts Receivable, Billable to Clients Accounts receivable, billable to clients are primarily comprised of production and media costs that have been incurred but have not yet been billed to clients, as well as fees that have been earned which have not yet been billed to clients. Unbilled amounts are presented in expenditures billable to clients regardless of whether they relate to our fees or production and media costs. A provision is made for unrecoverable costs as deemed appropriate. Accounts Payable Accounts payable includes all operating payables, including those related to all media and production costs. These payables are due within one year. Investments Equity investments with readily determinable fair values, other than those accounted for using the equity method of accounting, will be measured at fair value. We regularly review our investments to determine whether a significant event or change in circumstances has occurred that may impact the fair value of each investment, with changes to fair value recorded in earnings. We evaluate fair value based on specific information (valuation methodologies, estimates of appraisals, financial statements, etc.) in addition to quoted market price, if available. We consider all known quantitative and qualitative factors in determining if a decline in value of an investment has occurred. Derivatives We are exposed to market risk related to interest rates, foreign currency rates and certain balance sheet items. From time to time we enter into derivative instruments for risk management purposes, and not for speculative purposes. All derivative instruments are recorded at fair value on our balance sheet. Changes in fair value are immediately included in earnings if the derivatives are not designated as a hedge instrument or if the derivatives do not qualify as effective hedges. For derivatives designated as hedge instruments, we evaluate for hedge accounting both at inception and throughout the hedge period. If a derivative is designated as a fair value hedge, then changes in the fair value of the derivative are offset against the changes in the fair value of the underlying hedged item. If a derivative is designated as a cash flow hedge, then the changes in the fair value of the derivative are recognized as a component of accumulated other comprehensive income and subsequently reclassified to earnings in our Consolidated Statement of Operations in the same period as the underlying hedged transaction affects earnings. If a derivative is a net investment hedge, then the changes in the fair value of the derivative are recognized in other comprehensive income in the same period as the change in fair value of the underlying hedged foreign investment. Property and Equipment Furniture, equipment, leasehold improvements and buildings are stated at cost, net of accumulated depreciation. Furniture and equipment are depreciated generally using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 7 years for furniture and equipment, 10 to 35 years for buildings and the shorter of the useful life or the remaining lease term for leasehold improvements. Land is stated at cost and is not depreciated. We capitalize certain internal and external costs incurred to acquire or create internal use software, principally related to our enterprise resource planning (“ERP”) systems. Our ERP systems are stated at cost, net of accumulated amortization, and are amortized using the straight-line method over 10 years. All other internal use computer software are stated at cost, net of accumulated amortization and are amortized using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 7 years. Leases Effective January 1, 2019, we adopted Accounting Standards Codification Topic 842, Leases ("ASC 842"), using the modified retrospective transition method. As such, we recognized a right-of-use asset and a corresponding lease liability on our Consolidated Balance Sheet for virtually all of our leases with a term of more than twelve months. Prior-year financial statements were not recast under the new standard. As an accounting policy, we have elected not to apply the recognition requirements to short-term leases, not to separate non-lease components from lease components, and have elected the package of transition provisions available for existing contracts, which allowed us to carry forward our historical assessments of (i) whether contracts are or contain leases, (ii) lease classification and (iii) initial direct costs. The adoption of ASC 842 resulted in operating lease right-of-use assets of $1,421.1 and operating lease liabilities of $1,544.4 as of January 1, 2019. We do not have a material amount of finance leases and the majority of our operating leases, for which we serve as the lessee, consist primarily of real-estate property for our offices around the world. Both the asset and liability are measured at the present value of the future lease payments, with the asset being subject to adjustments such as initial direct costs, prepaid lease payments, and lease incentives. Many of our leases provide for renewal and/or termination options, as well as escalation clauses, which are also factored into our lease payments when appropriate. Our leases have remaining lease terms of 1 year to 20 years. The discount rate used to measure the lease asset and liability is determined at the beginning of the lease term using the rate implicit in the lease, if readily determinable, or using the Company's collateralized credit-adjusted borrowing rate. Goodwill and Other Intangible Assets We account for our business combinations using the acquisition accounting method, which requires us to determine the fair value of net assets acquired and the related goodwill and other intangible assets. Determining the fair value of assets acquired and liabilities assumed requires management's judgment and involves the use of significant estimates, including projections of future cash inflows and outflows, discount rates, asset lives and market multiples. Considering the characteristics of advertising, specialized marketing and communication services companies, our acquisitions usually do not have significant amounts of tangible assets, as the principal asset we typically acquire is creative talent. As a result, a substantial portion of the purchase price is allocated to goodwill and other intangible assets. We review goodwill as of October 1 st each year and whenever events or significant changes in circumstances indicate that the carrying value may not be recoverable. We evaluate the recoverability of goodwill at a reporting unit level. We have 12 reporting units that were subject to the 2019 annual impairment testing. Our annual impairment review as of October 1, 2019 did not result in an impairment charge for any of our reporting units. Intangible assets with indefinite useful lives are not amortized but are evaluated for impairment annually or more frequently if events or changes in circumstances indicate that impairment may exist. The Company first assesses qualitative factors to determine whether it is necessary to perform a quantitative impairment test for indefinite-lived intangible assets. Impairment exists if the fair value of the indefinite-lived intangible asset is less than the carrying value. Our annual impairment review as of October 1, 2019 did not result in an impairment charge for any of our intangible assets with indefinite useful lives. For reporting units not included in the qualitative assessment, or for any reporting units identified in the qualitative assessment as "more likely than not" that the fair value is less than its carrying value, the quantitative impairment test is performed. For our annual impairment test, we compare the respective fair value of our reporting units' equity to the carrying value of their net assets. The sum of the fair values of all our reporting units is also reconciled to our current market capitalization plus an estimated control premium. Goodwill allocated to a reporting unit whose fair value is equal to or greater than its carrying value is not impaired, and no further testing is required. Should the carrying amount for a reporting unit exceed its fair value, then the quantitative impairment test is failed and impaired goodwill is written down to its fair value with a charge to expense in the period the impairment is identified. The fair value of each reporting unit for 2019 and 2018 was estimated using a combination of the income approach, which incorporates the use of the discounted cash flow method, and the market approach, which incorporates the use of earnings and revenue multiples based on market data. We review intangible assets with definite lives subject to amortization whenever events or circumstances indicate that a carrying amount of an asset may not be recoverable. Recoverability of these assets is determined by comparing the carrying value of these assets to the estimated undiscounted future cash flows expected to be generated by these asset groups. These asset groups are impaired when their carrying value exceeds their fair value. Impaired intangible assets with definite lives subject to amortization are written down to their fair value with a charge to expense in the period the impairment is identified. Intangible assets with definite lives are amortized on a straight-line basis with estimated useful lives generally between 7 and 15 years. Events or circumstances that might require impairment testing include the loss of a significant client, the identification of other impaired assets within a reporting unit, loss of key personnel, the disposition of a significant portion of a reporting unit, significant decline in stock price or a significant adverse change in business climate or regulations. Foreign Currencies The functional currency of our foreign operations is generally their respective local currency. Assets and liabilities are translated at the exchange rates in effect at the balance sheet date, and revenues and expenses are translated at the average exchange rates during the period presented. The resulting translation adjustments are recorded as a component of accumulated other comprehensive loss in the stockholders’ equity section of our Consolidated Balance Sheets. Currency transaction gains or losses primarily arising from transactions in currencies other than the functional currency are included in office and general expenses. Foreign currency transactions resulted in a pre-tax loss of $5.3 for the year ended December 31, 2019 and pre-tax gains of $5.6 and $1.9 in for the years ended December 31, 2018 and 2017 , respectively. We monitor the currencies of countries in which we operate in order to determine if the country should be considered a highly inflationary environment. A currency is determined to be highly inflationary when there is cumulative inflation of approximately 100% or more over a three-year period. If this occurs the functional currency of that country is changed to our reporting currency, the U.S. Dollar, and foreign exchange gains or losses are recognized on all monetary transactions, assets and liabilities in currencies other than the U.S. Dollar until the currency is no longer considered highly inflationary. Income Taxes The provision for income taxes includes U.S. federal, state, local and foreign taxes. Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be reversed. We evaluate the realizability of our deferred tax assets and establish a valuation allowance when it is “more likely than not” that all or a portion of the deferred tax assets will not be realized. We evaluate our tax positions using the “more likely than not” recognition threshold and then apply a measurement assessment to those positions that meet the recognition threshold. The factors used in assessing valuation allowances include all available evidence, such as past operating results, estimates of future taxable income and the feasibility of tax planning strategies. We have established tax reserves that we believe to be adequate in relation to the potential for additional assessments in each of the jurisdictions in which we are subject to taxation. We regularly assess the likelihood of additional tax assessments in those jurisdictions and adjust our reserves as additional information or events require. Redeemable Noncontrolling Interests Many of our acquisitions include provisions under which the noncontrolling equity owners can require us to purchase additional interests in a subsidiary at their discretion. Payments for these redeemable noncontrolling interests may be contingent on projected operating performance and satisfying other conditions specified in the related agreements. These payments are also subject to revision in accordance with the terms of the agreements. We record these redeemable noncontrolling interests in “mezzanine equity” in our Consolidated Balance Sheets. Each reporting period, redeemable noncontrolling interests are reported at their estimated redemption value, but not less than their initial fair value. Any adjustment to the redemption value above initial value prior to exercise will also impact retained earnings or additional paid-in capital (“APIC”), but will not impact net income. Adjustments as a result of currency translation will affect the redeemable noncontrolling interest balance, but do not impact retained earnings or additional paid-in capital. Earnings Per Share (“EPS”) Basic EPS available to IPG common stockholders equals net income available to IPG common stockholders divided by the weighted-average number of common shares outstanding for the applicable period. Diluted EPS equals net income available to IPG common stockholders divided by the weighted-average number of common shares outstanding, plus any additional common shares that would have been outstanding if potentially dilutive shares had been issued. Diluted EPS reflect the potential dilution that would occur if certain potentially dilutive securities were exercised. The potential issuance of common stock is assumed to occur at the beginning of the year (or at the time of issuance of the potentially dilutive instrument, if later) and the incremental shares are included using the treasury stock method. The proceeds utilized in applying the treasury stock method consist of the amount, if any, to be paid upon exercise and, as it relates to stock-based compensation, the amount of compensation cost attributed to future service not yet recognized. These proceeds are then assumed to be used to purchase common stock at the average market price of our stock during the period. The incremental shares (difference between the shares assumed to be issued and the shares assumed to be purchased), to the extent they would have been dilutive, are included in the denominator of the diluted EPS calculation. We may be required to calculate basic EPS using the two-class method as a result of our redeemable noncontrolling interests. To the extent that the redemption value increases and exceeds the then-current fair value of a redeemable noncontrolling interest, net income available to IPG common stockholders (used to calculate EPS) could be negatively impacted by that increase, subject to certain limitations. The partial or full recovery of any reductions to net income available to IPG common stockholders (used to calculate EPS) is limited to any cumulative prior-period reductions. For the years ended December 31, 2019 , 2018 and 2017 , there was no impact to EPS for adjustments related to our redeemable noncontrolling interests. Pension and Postretirement Benefits We have pension and postretirement benefit plans covering certain domestic and international employees. We use various actuarial methods and assumptions in determining our net pension and postretirement benefit costs and obligations, including the discount rate used to determine the present value of future benefits, expected long-term rate of return on plan assets and healthcare cost trend rates. The overfunded or underfunded status of our pension and postretirement benefit plans is recorded on our Consolidated Balance Sheet. Stock-Based Compensation Compensation costs related to share-based transactions, including employee stock options, are recognized in the Consolidated Financial Statements based on fair value. Stock-based compensation expense is generally recognized ratably over the requisite service period based on the estimated grant-date fair value, net of estimated forfeitures. Treasury Stock We account for repurchased common stock under the cost method and include such treasury stock as a component of our Consolidated Statements of Stockholders' Equity. Upon retirement, we reduce common stock for the par value of the shares being retired and the excess of the cost of the shares over par value as a reduction to APIC, to the extent there is APIC in the same class of stock, and any remaining amount to retained earnings. These retired shares remain authorized but unissued. During 2019 , there

Revenue (Notes)

Revenue (Notes)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	Revenue Disaggregation of Revenue The following is a description of the principal activities, by reportable segment, from which we generate revenue. For more detailed information about reportable segments, see Note 15 . Integrated Agency Networks The Integrated Agency Networks ("IAN") segment of IPG principally generates revenue from providing advertising and media services as well as a comprehensive array of global communications, marketing services and data management. Within IAN’s advertising business, we typically identify two performance obligations for creative and production services. Depending on the arrangement, we typically act as the principal for our creative services and as the agent for our production services. Within our media business, we also identify two performance obligations for media planning and media buying services. We typically act as the principal for our media planning services and as the agent for media buying services. Generally, our branding arrangements consist of two performance obligations, and we act as the principal for both performance obligations. Constituency Management Group The Constituency Management Group ("CMG") segment generates revenue from providing events and public relations services as well as sports and entertainment marketing, corporate and brand identity, and strategic marketing consulting. In CMG’s events and public relations arrangements, we typically identify one performance obligation, for which we act as the principal in most arrangements. Generally, our branding arrangements consist of two performance obligations, and we act as the principal for both performance obligations. Principal Geographic Markets Our agencies are located in over 100 countries, including every significant world market. Our geographic revenue breakdown is listed below. Years ended December 31, Total revenue: 2019 2018 2017 United States $ 6,368.7 $ 5,851.0 $ 5,417.3 International: United Kingdom 871.8 881.4 775.7 Continental Europe 842.9 840.2 780.6 Asia Pacific 1,102.3 1,170.8 1,106.4 Latin America 431.6 389.0 386.6 Other 604.0 582.0 581.0 Total International 3,852.6 3,863.4 3,630.3 Total Consolidated $ 10,221.3 $ 9,714.4 $ 9,047.6 Years ended December 31, Net revenue: 2019 2018 2017 United States $ 5,386.1 $ 4,825.0 $ 4,458.8 International: United Kingdom 727.0 711.7 613.1 Continental Europe 742.4 737.5 687.8 Asia Pacific 858.3 896.8 866.9 Latin America 389.9 350.1 350.8 Other 521.4 510.5 496.1 Total International 3,239.0 3,206.6 3,014.7 Total Consolidated $ 8,625.1 $ 8,031.6 $ 7,473.5 IAN Years ended December 31, Total revenue: 2019 2018 2017 United States $ 4,912.5 $ 4,447.0 $ 4,062.3 International 3,113.9 3,109.1 2,947.3 Total IAN $ 8,026.4 $ 7,556.1 $ 7,009.6 Net revenue: United States $ 4,557.5 $ 4,000.4 $ 3,660.6 International 2,790.7 2,767.1 2,606.1 Total IAN $ 7,348.2 $ 6,767.5 $ 6,266.7 CMG Years ended December 31, Total revenue: 2019 2018 2017 United States $ 1,456.2 $ 1,404.0 $ 1,355.0 International 738.7 754.3 683.0 Total CMG $ 2,194.9 $ 2,158.3 $ 2,038.0 Net revenue: United States $ 828.6 $ 824.6 $ 798.2 International 448.3 439.5 408.6 Total CMG $ 1,276.9 $ 1,264.1 $ 1,206.8 Contract Balances The following table provides information about receivables, contract assets and contract liabilities from contracts with customers. December 31, December 31, Accounts receivable, net of allowance of $40.2 and $42.5, respectively $ 5,209.2 $ 5,126.6 Accounts receivable, billable to clients 1,934.1 1,900.6 Contract assets 63.0 67.9 Contract liabilities (deferred revenue) 585.6 533.9 Contract assets are primarily comprised of contract incentives that are generally satisfied annually under the terms of our contracts and are transferred to accounts receivable when the right to payment becomes unconditional. Contract liabilities relate to advance consideration received from customers under the terms of our contracts primarily related to reimbursements of third-party expenses, whether we act as principal or agent, and to a lesser extent, periodic retainer fees, both of which are generally recognized shortly after billing. The majority of our contracts are for periods of one year or less with the exception of our data management contracts. For those contracts with a term of more than one year, we had approximately $704.0 of unsatisfied performance obligations as of December 31, 2019, which will be recognized as services are performed over the remaining contractual terms through 2026.

Debt and Credit Agreements (Not

Debt and Credit Agreements (Notes)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Debt and Credit Arrangements Long-Term Debt A summary of the carrying amounts and fair values of our long-term debt is listed below. Effective Interest Rate December 31, 2019 2018 Book Value Fair Value 1 Book Value Fair 1 3.50% Senior Notes due 2020 (less unamortized discount and issuance costs of $0.4 and $1.1, respectively) 3.89 % $ 498.5 $ 505.4 $ 496.6 $ 499.9 3.75% Senior Notes due 2021 (less unamortized discount and issuance costs of $0.2 and $1.9, respectively) 3.98 % 497.9 513.5 496.8 503.2 4.00% Senior Notes due 2022 (less unamortized discount and issuance costs of $0.7 and $0.6, respectively) 4.13 % 248.7 258.8 248.2 250.3 3.75% Senior Notes due 2023 (less unamortized discount and issuance costs of $0.5 and $1.3, respectively) 4.32 % 498.2 522.8 497.7 491.4 4.20% Senior Notes due 2024 (less unamortized discount and issuance costs of $0.4 and $1.8, respectively) 4.24 % 497.8 538.1 497.3 492.6 4.65% Senior Notes due 2028 (less unamortized discount and issuance costs of $1.5 and $3.9, respectively) 4.78 % 494.6 564.3 494.0 494.1 5.40% Senior Notes due 2048 (less unamortized discount and issuance costs of $2.7 and $5.4, respectively) 5.48 % 491.9 617.1 491.7 474.1 Term Loan due 2021 - LIBOR plus 1.25% — — 400.0 400.0 Other notes payable and capitalized leases 46.3 45.5 38.0 38.0 Total long-term debt 3,273.9 3,660.3 Less: current portion 502.0 0.1 Long-term debt, excluding current portion $ 2,771.9 $ 3,660.2 1 See Note 13 for information on the fair value measurement of our long-term debt. Annual maturities are scheduled as follows based on the book value as of December 31, 2019 . 2020 $ 502.0 2021 501.4 2022 248.9 2023 498.3 2024 497.8 Thereafter 1,025.5 Total long-term debt $ 3,273.9 Our 3.50% Senior Notes in aggregate principal amount of $500.0 mature on October 1, 2020. We expect to use available cash as well as additional commercial paper as needed. For those debt securities that have a premium or discount at the time of issuance, we amortize the amount through interest expense based on the maturity date or the first date the holders may require us to repurchase the debt securities, if applicable. A premium would result in a decrease in interest expense, and a discount would result in an increase in interest expense in future periods. Additionally, we have debt issuance costs related to certain financing transactions which are also amortized through interest expense. As of December 31, 2019 and 2018 , we had total unamortized debt issuance costs of $21.6 and $26.0 , respectively. Our debt securities include covenants that, among other things, limit our liens and the liens of certain of our consolidated subsidiaries, but do not require us to maintain any financial ratios or specified levels of net worth or liquidity. Debt Transactions Term Loan Agreement On October 1, 2018, in order to fund the acquisition of Acxiom, we entered into financing arrangements with third-party lenders under a three-year term loan agreement (the "Term Loan Agreement"). We fully paid off the outstanding balance under the Term Loan Agreement as of December 31, 2019, with payments of $100.0 , $200.0 and $100.0 , on June 13, 2019, September 9, 2019 and December 12, 2019, respectively. Credit Agreements We maintain a committed corporate credit facility, originally dated as of July 18, 2008, which has been amended and restated from time to time (the "Credit Agreement"). We use our Credit Agreement to increase our financial flexibility, to provide letters of credit primarily to support obligations of our subsidiaries and to support our commercial paper program. On November 1, 2019, we entered into an amendment and restatement (the "Amendment") of the Credit Agreement. Under the Amendment, among other things, the maturity date of the Credit Agreement was extended to November 1, 2024, and the cost structure of the Credit Agreement was changed. The Amendment also removed the interest coverage ratio financial covenant; however, the Company remains subject to the leverage ratio financial covenant, among other customary covenants. At the election of the Company, the leverage ratio financial covenant may be changed to not more than 4.00 to 1.00 for four consecutive fiscal quarters, beginning with the fiscal quarter in which there is an occurrence of one or more acquisitions with an aggregate purchase price of at least $200.0 . The Credit Agreement is a revolving facility under which amounts borrowed by us or any of our subsidiaries designated under the Credit Agreement may be repaid and reborrowed, subject to an aggregate lending limit of $1,500.0 , or the equivalent in other currencies. The Company has the ability to increase the commitments under the Credit Agreement from time to time by an additional amount of up to $250.0 , provided the Company receives commitments for such increases and satisfies certain other conditions. The aggregate available amount of letters of credit outstanding may decrease or increase, subject to a sublimit on letters of credit of $50.0 , or the equivalent in other currencies. Our obligations under the Credit Agreement are unsecured. As of December 31, 2019 and 2018 , there were no borrowings under the Credit Agreement; however, we had $8.4 and $8.5 of letters of credit under the Credit Agreement, which reduced our total availability to $1,491.6 and $1,491.5 , respectively. Under the Credit Agreement, we can elect to receive advances bearing interest based on either the Base Rate or the Eurocurrency rate (each as defined in the Credit Agreement) plus an applicable margin that is determined based on our credit ratings. As of December 31, 2019 , the applicable margin was 0.125% for Base Rate advances and 1.125% for Eurocurrency Rate borrowings. Letter of credit fees accrue on the average daily aggregate amount of letters of credit outstanding, at a rate equal to the applicable margin for Eurocurrency rate advances, and fronting fees accrue on the aggregate amount of letters of credit outstanding at an annual rate of 0.25% . We also pay a facility fee on each lender's revolving commitment of 0.125% , which is an annual rate determined based on our credit ratings. In addition to other and customary covenants, we are required to maintain the financial covenant listed below as of the end of each fiscal quarter for the period of four fiscal quarters then ended pursuant to our Credit Agreement. We were in compliance with our covenant in the Credit Agreement as of December 31, 2019 . Financial Covenants 1 Leverage ratio (not greater than): 1 3.75x 1 The leverage ratio is defined as debt as of the last day of such fiscal quarter to EBITDA, as defined in the Credit Agreement, for the four quarters then ended. Pursuant to July 2018 Amendment No. 1 to the Credit Agreement, the maximum leverage ratio decreased from 4.00x to 3.75x on the last day of the fourth full fiscal quarter ending after the Acxiom closing date on October 1, 2018. We also have uncommitted lines of credit with various banks that permit borrowings at variable interest rates and that are primarily used to fund working capital needs. We have guaranteed the repayment of some of these borrowings made by certain subsidiaries. If we lose access to these credit lines, we would have to provide funding directly to some of our operations. As of December 31, 2019 and 2018 , the Company had uncommitted lines of credit in an aggregate amount of $1,056.0 and $1,173.1 , under which we had outstanding borrowings of $52.4 and $73.7 classified as short-term borrowings on our Consolidated Balance Sheets, respectively. The average amounts outstanding during 2019 and 2018 were $88.0 and $96.4 , respectively, with weighted-average interest rates of approximately 5.2% and 4.5% , respectively. Commercial Paper The Company is authorized to issue unsecured commercial paper up to a maximum aggregate amount outstanding at any time of $1,500.0 . Borrowings under the commercial paper program are supported by the Credit Agreement described above. Commercial paper proceeds are used for working capital and general corporate purposes, including the repayment of maturing indebtedness and other short-term liquidity needs. Commercial paper maturities vary but may not exceed 397 days from the date of issue. As of December 31, 2019 and 2018 , there was no commercial paper outstanding. The average amounts outstanding under the program in 2019 and 2018 were $312.9 and $648.7 with weighted-average interest rates of approximately 2.5% and 2.4% and weighted-average maturities of thirteen and twenty-two days , respectively. Cash Pooling We aggregate our domestic cash position on a daily basis. Outside the United States, we use cash pooling arrangements with banks to help manage our liquidity requirements. In these pooling arrangements, several IPG agencies agree with a single bank that the cash balances of any of the agencies with the bank will be subject to a full right of set-off against amounts other agencies owe the bank, and the bank provides for overdrafts as long as the net balance for all agencies does not exceed an agreed-upon level. Typically, each agency pays interest on outstanding overdrafts and receives interest on cash balances. Our Consolidated Balance Sheets reflect cash, net of bank overdrafts, under all of our pooling arrangements, and as of December 31, 2019 and 2018 the amounts netted were $2,274.9 and $2,065.8 , respectively.

Earnings Per Share (Notes)

Earnings Per Share (Notes)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following sets forth basic and diluted earnings per common share available to IPG common stockholders. Years ended December 31, 2019 2018 2017 Net income available to IPG common stockholders $ 656.0 $ 618.9 $ 554.4 Weighted-average number of common shares outstanding - basic 386.1 383.3 389.6 Dilutive effect of stock options and restricted shares 5.1 5.7 7.7 Weighted-average number of common shares outstanding - diluted 391.2 389.0 397.3 Earnings per share available to IPG common stockholders: Basic $ 1.70 $ 1.61 $ 1.42 Diluted $ 1.68 $ 1.59 $ 1.40

Acquisitions (Notes)

Acquisitions (Notes)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	Acquisitions Acxiom Acquisition On October 1, 2018, pursuant to the terms of the Membership Interest Purchase Agreement dated as of July 2, 2018, the Company completed the acquisition of Acxiom Holdings, Inc.’s Marketing Solutions business ("Acxiom") through the acquisition of 100% of the equity interests of Acxiom for $2,327.9 , subject to customary closing adjustments. The purpose of the acquisition is to combine the Company's media, creative, marketing services and analytics capabilities, global scale and consumer insights, with Acxiom's expertise in identity, data, integrations and data stewardship. The Company funded the acquisition of Acxiom from a term loan agreement with third-party lenders for $500.0 and unsecured senior notes issued for a total of $2,000.0 in aggregate principal amount. The following table summarizes the fair values of the assets acquired and liabilities assumed at the closing date: October 1, 2018 Cash and cash equivalents $ 13.3 Accounts receivable 112.9 Accounts receivable, billable to clients 8.3 Other current assets 28.2 Property and equipment, net 159.7 Deferred income taxes (0.6 ) Goodwill 1,110.8 Intangible assets, net 995.0 Other non-current assets 8.3 Accounts payable (37.1 ) Accrued liabilities (46.9 ) Contract liabilities (23.2 ) Other non-current liabilities (0.8 ) Net assets acquired $ 2,327.9 The fair values of the identifiable intangible assets acquired at the closing date are as follows: Fair Value Weighted Average Amortization Period (Years) Customer lists $ 600.0 15.0 Know-how and technology 235.0 9.0 Trade names 160.0 15.0 to indefinite Total intangible assets $ 995.0 The fair value of the customer lists was determined by applying the multi-period excess earnings method, a variation of the income approach. The fair values of the know-how and technology and the trade names were determined using the relief from royalty method of the income approach. Goodwill generated by the Acxiom acquisition, the majority of which is tax deductible, primarily relates to intangible assets that do not qualify for separate recognition, including assembled workforce and synergies. The purchase accounting for the transaction was finalized during the third quarter of 2019, including the assignment of goodwill related to the transaction-associated synergies. There were no material adjustments to the preliminary amounts recorded. The operating results of Acxiom for the period from October 1, 2018 to December 31, 2018, including net revenue of $181.7 and net income available to IPG common stockholders of $20.4 , are included in our Consolidated Statements of Operations for the year ended December 31, 2018. The Company incurred a total of $35.0 in "Selling, general and administrative expenses," $3.7 in "Interest expense," $0.4 in "Interest income" and $10.3 in "Other expense, net," for transaction-related costs in connection with the acquisition. The following table presents the combined results of the Company and Acxiom for the years ended December 31, 2018 and 2017 on an unaudited pro forma basis, as if the acquisition had occurred on January 1, 2017. The unaudited pro forma financial information is presented for informational purposes only and is not indicative of the results of operations that would have been achieved if that acquisition had taken place at the beginning of January 1, 2017. It also does not reflect changes in cost structure or operations resulting from restructuring activities, changes in the business, or future events that may occur after the completion of the acquisition. The pro forma combined results of operations shown below include after-tax nonrecurring transaction-related charges of $27.6 in 2017, and the business combination accounting effects resulting from the acquisition. (Unaudited) December 31, 2018 2017 Pro forma revenues $ 10,230.4 $ 9,736.1 Pro forma net income 642.2 519.2 Other Acquisitions We continue to evaluate strategic opportunities to expand our industry expertise, strengthen our position in high-growth and key strategic geographical markets and industry sectors, advance technological capabilities and improve operational efficiency through both acquisitions and increased ownership interests in current investments. Our acquisitions typically provide for an initial payment at the time of closing and additional contingent purchase price payments based on the future performance of the acquired entity. We have entered into agreements that may require us to purchase additional equity interests in certain consolidated and unconsolidated subsidiaries. The amounts at which we record these transactions in our financial statements are based on estimates of the future financial performance of the acquired entity, the timing of the exercise of these rights, changes in foreign currency exchange rates and other factors. During 2019 , we completed one acquisition, a content communications agency based in the U.K. This acquisition was included in the IAN reportable segment. During 2019 , we recorded approximately $7.6 of goodwill and other intangible assets related to our acquisitions. During 2018 , we completed five acquisitions, two of which were included in the IAN reportable segment, and three of which were included in the CMG reportable segment. These acquisitions include a data and technology company based in the U.S., as discussed in detail above, a full-service digital agency based in Brazil, an entertainment marketing and brand licensing agency in the fashion and lifestyle sector based in the U.K., a content-focused social creative agency based in the U.K. and a content production firm based in Israel. During 2018 , we recorded approximately $2,131.0 of goodwill and other intangible assets related to our acquisitions. During 2017 , we completed ten acquisitions, eight of which were included in the IAN reportable segment, and two of which were included in the CMG reportable segment. The most significant acquisitions included a product and service design consultancy based in the U.S., an integrated healthcare marketing communications agency based in the U.S., a content creation and digital agency with offices in the U.S. and the U.K., a mobile consultancy and application development agency based in the U.K., a full-service public relations and digital agency based in China, a search engine optimization and digital content marketing agency based in the U.K., and a mobile focused digital agency based in the U.K. During 2017 , we recorded approximately $62.0 of goodwill and other intangible assets related to our acquisitions. The results of operations of our acquired companies were included in our consolidated results from the closing date of each acquisition. We did not make any payments in stock related to our acquisitions in 2019 , 2018 or 2017 . Details of cash paid for current and prior years' acquisitions are listed below. Years ended December 31, 2019 2018 2017 Cost of investment: current-year acquisitions 1 $ 0.6 $ 2,323.4 $ 36.8 Cost of investment: prior-year acquisitions 15.8 33.9 54.6 Less: net cash acquired — (13.8 ) (7.1 ) Total cost of investment 16.4 2,343.5 84.3 Operating payments 2 9.3 19.4 47.1 Total cash paid for acquisitions 3 $ 25.7 $ 2,362.9 $ 131.4 1 The cost of investment: current-year acquisitions line significantly increased in the year ended December 31, 2018, primarily as a result of payments related to the acquisition of Acxiom. 2 Represents cash payments for amounts that have been recognized in operating expenses since the date of acquisition either relating to adjustments to estimates in excess of the initial value of contingent payments recorded or were contingent upon the future employment of the former owners of the acquired companies. Amounts are reflected in the operating section of the Consolidated Statements of Cash Flows. 3 Of the total cash paid for acquisitions, $0.6 , $2,309.8 and $30.6 for the years ended December 31, 2019 , 2018 and 2017 , respectively, are classified under the investing section of the Consolidated Statements of Cash Flows as acquisitions, net of cash acquired. These amounts relate to initial payments for new transactions. Of the total cash paid for acquisitions, $15.8 , $33.7 and $53.7 for the years ended December 31, 2019 , 2018 and 2017 , respectively, are classified under the financing section of the Consolidated Statements of Cash Flows as acquisition-related payments. These amounts relate to deferred payments and increases in our ownership interest for prior acquisitions. For companies acquired, we estimate the fair values of the assets and liabilities based on 100% of the business for consolidation. The purchase price in excess of the estimated fair value of the tangible net assets acquired is allocated to identifiable intangible assets and then to goodwill. Due to the characteristics of advertising, specialized marketing and communication services companies, our acquisitions typically do not have significant amounts of tangible assets since the principal assets we acquire are client relationships and talent. As a result, a substantial portion of the purchase price is primarily allocated to customer lists, trade names and goodwill. For acquisitions we record deferred payment and redeemable noncontrolling interest amounts on our Consolidated Balance Sheets based on their acquisition-date fair value. Deferred payments are recorded on a discounted basis and adjusted quarterly, if necessary, through operating income or net interest expense, depending on the nature of the arrangement, for both changes in estimate and accretion between the acquisition date and the final payment date. See Note 16 for further information on contingent acquisition obligations. Redeemable noncontrolling interests are adjusted quarterly, if necessary, to their estimated redemption value, but not less than their initial fair value. Any adjustments to the redemption value impact retained earnings or additional paid in capital, except for foreign currency translation adjustments. The following table presents changes in our redeemable noncontrolling interests. Years ended December 31, 2019 2018 2017 Balance at beginning of period $ 167.9 $ 252.1 $ 252.8 Change in related noncontrolling interests balance (2.8 ) (10.7 ) (2.8 ) Changes in redemption value of redeemable noncontrolling interests: Additions 24.3 0.0 7.7 Redemptions and other (24.9 ) (33.7 ) (18.5 ) Redemption value adjustments 0.2 (39.8 ) 12.9 Balance at end of period $ 164.7 $ 167.9 $ 252.1 For all acquisitions, if a portion of the deferred payments and purchases of additional interests after the effective date of purchase are contingent upon employment terms, then that amount is accounted for separately from the business combination and recognized as compensation expense over the required earn-out period. Payments deemed as compensation are excluded from the fair value purchase price allocation to tangible net assets and intangible assets acquired.

Supplementary Data (Notes)

Supplementary Data (Notes)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Supplementary Data [Abstract]
Supplementary Data	Valuation and Qualifying Accounts – Allowance for Uncollectible Accounts Receivable Years ended December 31, 2019 2018 2017 Balance at beginning of period $ 42.5 $ 42.7 $ 55.7 Charges to costs and expenses 10.1 6.5 9.5 Adjustments: Acquisitions/(dispositions) (0.3 ) 2.2 (1.0 ) Uncollectible accounts written off (11.9 ) (7.1 ) (25.5 ) Foreign currency translation adjustments (0.2 ) (1.8 ) 4.0 Balance at end of period $ 40.2 $ 42.5 $ 42.7 Property and Equipment December 31, 2019 2018 Furniture and equipment $ 694.3 $ 681.7 Leasehold improvements 634.9 629.0 Internal-use computer software 422.0 368.5 Land and buildings 143.3 146.6 Gross property and equipment 1,894.5 1,825.8 Less: accumulated depreciation and amortization (1,116.4 ) (1,034.9 ) Total property and equipment, net $ 778.1 $ 790.9 Total depreciation and amortization expense, which excludes the amortization of acquired intangibles, for property and equipment for the years ended December 31, 2019 , 2018 and 2017 was $192.5 , $165.3 and $136.0 , respectively. Accrued Liabilities The following table presents the components of accrued liabilities. December 31, 2019 2018 Salaries, benefits and related expenses $ 494.1 $ 494.9 Acquisition obligations 45.7 65.7 Office and related expenses 26.9 52.2 Interest 38.8 43.6 Restructuring charges 1.6 0.0 Other 135.7 150.5 Total accrued liabilities $ 742.8 $ 806.9 Other Expense, Net Results of operations include certain items that are not directly associated with our revenue-producing operations. Years ended December 31, 2019 2018 2017 Net losses on sales of businesses $ (43.4 ) $ (61.9 ) $ (24.1 ) Other 0.5 (7.7 ) (2.1 ) Total other expense, net $ (42.9 ) $ (69.6 ) $ (26.2 ) Net losses on sales of businesses – During 2019 , the amounts recognized were related to sales of businesses and the classification of certain assets and liabilities, consisting primarily of cash, as held for sale within our IAN and CMG reportable segments. During 2018 , the amounts recognized were related to sales of businesses and the classification of certain assets and liabilities, consisting primarily of cash, as held for sale within our IAN and CMG reportable segments. During 2017 , the amounts recognized were related to sales of businesses and the classification of certain assets and liabilities, consisting primarily of cash, accounts receivable and accounts payable, as held for sale within our IAN reportable segment. The businesses held for sale as of year end primarily represent unprofitable, non-strategic agencies which are expected to be sold within the next twelve months. Other – During 2019 , the amounts recognized are primarily a result of changes in fair market value of equity investments, partially offset by the sale of an equity investment. During 2018 Share Repurchase Program On July 2, 2018, in connection with the announcement of the Acxiom acquisition, we announced that share repurchases will be suspended for a period of time in order to reduce the increased debt levels incurred in conjunction with the acquisition. As of December 31, 2019 , $338.4 , excluding fees, remains available for repurchase under the share repurchase programs authorized in previous years, which has no expiration date. Supplemental Cash Flow Information Years ended December 31, 2019 2018 2017 Cash paid for interest $ 192.7 $ 88.7 $ 82.3 Cash paid for income taxes, net of refunds 1 150.2 207.9 228.4 1 Refunds of $92.6 , $24.3 and $31.9 were received for the years ended December 31, 2019 , 2018 and 2017 , respectively.	Supplementary Data

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets (Notes)	12 Months Ended
	Dec. 31, 2019
Goodwill and intangible assets [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	Goodwill and Other Intangible Assets Goodwill Goodwill is the excess purchase price remaining from an acquisition after an allocation of purchase price has been made to identifiable assets acquired and liabilities assumed based on estimated fair values. The changes in the carrying value of goodwill for our segments, IAN and CMG, for the years ended December 31, 2019 and 2018 are listed below. IAN 1 CMG Total 2 Balance as of December 31, 2017 $ 3,161.8 $ 658.6 $ 3,820.4 Acquisitions 1,112.0 20.0 1,132.0 Foreign currency and other (64.5 ) (12.0 ) (76.5 ) Balance as of December 31, 2018 $ 4,209.3 $ 666.6 $ 4,875.9 Acquisitions 2.1 0.7 2.8 Foreign currency and other 14.4 1.3 15.7 Balance as of December 31, 2019 $ 4,225.8 $ 668.6 $ 4,894.4 1 During 2018, the increase in goodwill is primarily due to the acquisition of Acxiom. See Note 6 for further information on the Acxiom acquisition. 2 For all periods presented, no goodwill impairment charge has been recorded. See Note 1 for information regarding our annual impairment methodology. Other Intangible Assets Other intangible assets primarily consist of customer lists and know-how and technology, which have definite lives and are subject to amortization on a straight-line basis with estimated useful lives generally between 7 and 15 years, as well as trade names which have both indefinite and definite lives which are subject to amortization on a straight-line basis with estimated useful lives of 15 years. Amortization expense for other intangible assets for the years ended December 31, 2019 , 2018 and 2017 was $86.0 , $37.6 and $21.1 , respectively. There were no material impairment charges on other intangibles for the years ended December 31, 2019 , 2018 and 2017 . During 2019 and 2018 , we recorded approximately $5.0 and $999.0 of other intangible assets related to our acquisitions in the respective year. The increase in 2018 is primarily due to the acquisition of Acxiom. The following table provides a summary of other intangible assets, which are included in our Consolidated Balance Sheets. December 31, 2019 2018 Gross Amount Accumulated Amortization Net Amount Gross Amount Accumulated Amortization Net Amount Customer lists $ 861.4 $ (244.6 ) $ 616.8 $ 857.2 $ (190.9 ) $ 666.3 Know-how and technology 235.0 (32.9 ) 202.1 235.0 (6.5 ) 228.5 Trade names 226.2 (41.3 ) 184.9 226.2 (36.8 ) 189.4 Other 14.3 (3.8 ) 10.5 14.3 (3.8 ) 10.5 Total $ 1,336.9 $ (322.6 ) $ 1,014.3 $ 1,332.7 $ (238.0 ) $ 1,094.7 The estimated annual amortization expense for other intangible assets for the next five years as of December 31, 2019 is listed below. 2020 2021 2022 2023 2024 Estimated amortization expense $ 88.4 $ 86.9 $ 82.9 $ 78.6 $ 76.8

Income Taxes (Notes)

Income Taxes (Notes)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes The components of income before income taxes are listed below. Years ended December 31, 2019 2018 2017 Domestic $ 557.4 $ 474.0 $ 514.8 Foreign 320.9 364.0 326.0 Total $ 878.3 $ 838.0 $ 840.8 The provision for income taxes is listed below. Years ended December 31, 2019 2018 2017 U.S. federal income taxes (including foreign withholding taxes): Current $ 92.2 $ 38.1 $ 154.1 Deferred 9.5 29.9 (37.6 ) 101.7 68.0 116.5 State and local income taxes: Current 10.7 25.1 18.8 Deferred 8.7 3.4 19.7 19.4 28.5 38.5 Foreign income taxes: Current 92.2 121.9 107.9 Deferred (8.5 ) (19.2 ) 8.4 83.7 102.7 116.3 Total $ 204.8 $ 199.2 $ 271.3 A reconciliation of the effective income tax rate as reflected in our Consolidated Statements of Operations to the U.S. federal statutory income tax rate is listed below. Years ended December 31, 2019 2018 2017 U.S. federal statutory income tax rate 21.0 % 21.0 % 35.0 % Income tax provision at U.S. federal statutory rate $ 184.5 $ 176.0 $ 294.3 State and local income taxes, net of U.S. federal income tax benefit 14.0 23.8 23.5 Impact of foreign operations, including withholding taxes 34.2 50.7 (6.7 ) U.S. tax incentives (21.4 ) (17.5 ) (1.3 ) Change in net valuation allowance 1 (26.3 ) (16.9 ) 1.4 Divestitures 9.6 11.7 1.1 U.S. federal tax credits 0.4 (48.1 ) (0.4 ) Stock compensation (3.3 ) (6.8 ) (15.3 ) Increase in unrecognized tax benefits 14.1 8.4 7.0 Net impact of the Tax Act 0.0 13.4 (36.0 ) Other (1.0 ) 4.5 3.7 Provision for income taxes $ 204.8 $ 199.2 $ 271.3 Effective income tax rate on operations 23.3 % 23.8 % 32.3 % 1 Reflects changes in valuation allowances that impacted the effective income tax rate for each year presented. In 2019 , our effective income tax rate of 23.3% was positively impacted by the reversal of valuation allowances primarily in Continental Europe, by the settlement of state income tax audits and by excess tax benefits on employee share-based payments. The effective tax rate was negatively impacted by losses in certain foreign jurisdictions where we receive no tax benefit due to 100% valuation allowances, net losses on sales of businesses and the classification of certain assets as held for sale, for which we received minimal tax benefit. In 2018 , our effective income tax rate of 23.8% was positively impacted by U.S. tax incentives, foreign tax credits from a distribution of unremitted earnings, the net reversal of valuation allowance in Continental Europe and research and development credits. The effective income tax rate was negatively impacted by losses in certain foreign jurisdictions where we received no tax benefit due to 100% valuation allowances, non-deductible losses on sales of businesses and assets held for sale, by tax expense associated with the change to our assertion regarding the permanent reinvestment of undistributed earnings attributable to certain foreign subsidiaries, and by tax expense related to the true-up of our December 31, 2017 tax reform estimates as permitted by SEC Staff issued Accounting Bulletin No. 118 (“SAB 118”). Public Law 115-97, commonly referred to as the Tax Cuts and Jobs Act (the "Tax Act") was signed into law on December 22, 2017. The Tax Act legislated many new tax provisions which have impacted our operations. At December 31, 2017, provisional amounts were recorded as permitted by SAB 118. The impact of the Tax Act as required by SAB 118, resulted in a tax expense of $13.4 in 2018, which was primarily attributable to our estimate of the tax imposed on the deemed repatriation of unremitted foreign earnings. The Tax Act imposed a new tax on certain foreign earnings generated in 2018 and forward. These global intangible low-taxed income ("GILTI") tax rules are complex. U.S. GAAP allowed us to choose an accounting policy which treats the U.S. tax under GILTI provisions as either a current expense, as incurred, or as a component of the Company’s measurement of deferred taxes. The Company elected to account for the GILTI tax as a current expense. In 2017 , our effective income tax rate of 32.3% was positively impacted by a net benefit of $36.0 as a result of the Tax Act as well as excess tax benefits on employee share-based payments, partially offset by losses in certain foreign jurisdictions where we receive no tax benefit due to 100% valuation allowances. The components of deferred tax assets and liabilities are listed below. December 31, 2019 2018 Postretirement/post-employment benefits $ 16.7 $ 17.9 Deferred compensation 99.5 99.8 Pension costs 23.7 22.2 Basis differences in fixed assets (75.3 ) (71.7 ) Rent — 27.3 Interest 45.5 48.8 Accruals and reserves 19.4 21.0 Allowance for doubtful accounts 6.5 7.4 Basis differences in intangible assets (321.0 ) (302.7 ) Investments in equity securities 0.3 1.2 Operating lease right-of-use assets (335.2 ) — Operating lease liabilities 361.4 — Tax loss/tax credit carry forwards 297.1 345.6 Prepaid expenses (6.7 ) (6.3 ) Deferred revenue (21.7 ) (26.8 ) Unremitted foreign earnings (1.3 ) (9.5 ) Other 44.5 38.2 Total deferred tax assets, net 153.4 212.4 Valuation allowance (164.2 ) (211.0 ) Net deferred tax (liabilities) assets $ (10.8 ) $ 1.4 We evaluate the realizability of our deferred tax assets on a quarterly basis. The realization of our deferred tax assets is primarily dependent on future earnings. The amount of the deferred tax assets considered realizable could be reduced or increased in the near future if estimates of future taxable income are lower or greater than anticipated. A valuation allowance is established when it is “more likely than not” that all or a portion of deferred tax assets will not be realized. In circumstances where there is negative evidence, establishment of a valuation allowance is considered. The factors used in assessing valuation allowances include all available evidence, such as past operating results, estimates of future taxable income and the feasibility of tax planning strategies. We believe that cumulative losses in the most recent three-year period represent significant negative evidence, and as a result, we determined that certain of our deferred tax assets required the establishment of a valuation allowance. The deferred tax assets for which an allowance was recognized relate primarily to state and foreign tax loss carryforwards. The change in the valuation allowance is listed below. Years ended December 31, 2019 2018 2017 Balance at beginning of period $ 211.0 $ 243.0 $ 255.6 Reversed to costs and expenses (24.9 ) (28.0 ) (4.6 ) (Reversed) charged to gross tax assets and other accounts 1 (19.8 ) 5.1 (27.3 ) Foreign currency translation (2.1 ) (9.1 ) 19.3 Balance at end of period $ 164.2 $ 211.0 $ 243.0 1 Primarily represents changes to the valuation allowance related to the change of a corresponding deferred tax asset. In 2019, 2018, and 2017, amounts reversed to costs and expenses primarily related to decreases in valuation allowances in Continental Europe for existing deferred tax assets. As of December 31, 2019 , there were $1,044.1 of loss carryforwards. These loss carryforwards were all non-U.S. tax loss carryforwards, of which $939.0 have unlimited carryforward periods and $105.1 have expiration periods from 2020 to 2040 . As of December 31, 2019 , the Company also had $25.6 in deferred tax assets for state net operating loss carryforwards and tax credit carryforwards, which will expire between 2020 and 2040 . As of December 31, 2019 and 2018 , we had $1,199.7 and $1,079.1 , respectively, of undistributed earnings attributable to foreign subsidiaries. The Company has historically asserted that its unremitted foreign earnings are permanently reinvested, and therefore has not recorded any deferred taxes on such amounts. It is not practicable to determine the deferred tax on these undistributed earnings because such liability, if any, is dependent on circumstances that exist if and when a remittance occurs, including the source location and amount of the distribution and foreign withholding taxes. During the third quarter ended September 30, 2018, as a result of our increased debt and associated servicing commitments in connection with the Acxiom acquisition that was consummated on October 1, 2018, the Company re-evaluated its global cash needs and as a result determined that approximately $435.0 of undistributed foreign earnings from certain international entities were no longer subject to the permanent reinvestment assertion. We recorded a tax expense of $10.8 in 2018 representing our estimate of the tax costs associated with this change to our assertion. We have not changed our permanent reinvestment assertion with respect to any other international entities as we intend to use the related historical earnings and profits to fund international operations and investments. The table below summarizes the activity related to our unrecognized tax benefits. Years ended December 31, 2019 2018 2017 Balance at beginning of period $ 335.4 $ 271.9 $ 246.7 Increases as a result of tax positions taken during a prior year 22.7 65.9 6.3 Decreases as a result of tax positions taken during a prior year (25.8 ) (10.8 ) (8.1 ) Settlements with taxing authorities (8.1 ) (6.5 ) (0.8 ) Lapse of statutes of limitation (0.6 ) (1.7 ) (3.3 ) Increases as a result of tax positions taken during the current year 21.7 16.6 31.1 Balance at end of period $ 345.3 $ 335.4 $ 271.9 Included in the total amount of unrecognized tax benefits of $345.3 as of December 31, 2019 , is $296.4 of tax benefits that, if recognized, would impact the effective income tax rate. The total amount of accrued interest and penalties as of December 31, 2019 and 2018 is $39.6 and $42.4 , respectively, of which a benefit of $2.8 and a detriment of $14.5 is included in our 2019 and 2018 Consolidated Statements of Operations, respectively. In accordance with our accounting policy, interest and penalties accrued on unrecognized tax benefits are classified as income taxes in our Consolidated Statements of Operations. We have various tax years under examination by tax authorities in the U.S., in various countries, and in various states, such as New York, in which we have significant business operations. It is not yet known whether these examinations will, in the aggregate, result in our paying additional taxes. We believe our tax reserves are adequate in relation to the potential for additional assessments in each of the jurisdictions in which we are subject to taxation. We regularly assess the likelihood of additional tax assessments in those jurisdictions and, if necessary, adjust our reserves as additional information or events require. With respect to all tax years open to examination by U.S. federal, various state and local, and non-U.S. tax authorities, we currently anticipate that total unrecognized tax benefits will decrease by an amount between $10.0 and $20.0 in the next twelve months, a portion of which will affect our effective income tax rate, primarily as a result of the settlement of tax examinations and the lapsing of statutes of limitations. This net decrease is related to various items of income and expense, primarily transfer pricing adjustments. We are effectively settled with respect to U.S. federal income tax audits through 2012, with the exception of 2009. With limited exceptions, we are no longer subject to state and local income tax audits for years prior to 2013 or non-U.S. income tax audits for years prior to 2009.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss, Net of Tax (Notes)	12 Months Ended
	Dec. 31, 2019
Accumulated Other Comprehensive Loss [Abstract]
Comprehensive Income (Loss) Note	Accumulated Other Comprehensive Loss, Net of Tax The following table presents the changes in accumulated other comprehensive loss, net of tax, by component. Foreign Currency Translation Adjustments Derivative Instruments Defined Benefit Pension and Other Postretirement Plans Total Balance as of December 31, 2017 $ (585.3 ) $ (6.8 ) $ (235.7 ) $ (827.8 ) Other comprehensive (loss) income before reclassifications (146.8 ) 0.0 11.4 (135.4 ) Amount reclassified from accumulated other comprehensive loss, net of tax 15.7 1.5 4.9 22.1 Balance as of December 31, 2018 $ (716.4 ) $ (5.3 ) $ (219.4 ) $ (941.1 ) Other comprehensive income (loss) before reclassifications 12.0 0.0 (14.7 ) (2.7 ) Amount reclassified from accumulated other comprehensive loss, net of tax 6.7 1.8 5.3 13.8 Balance as of December 31, 2019 $ (697.7 ) $ (3.5 ) $ (228.8 ) $ (930.0 ) Amounts reclassified from accumulated other comprehensive loss, net of tax, for the years ended December 31, 2019 , 2018 and 2017 are as follows: Years ended December 31, Affected Line Item in the Consolidated Statements of Operations 2019 2018 2017 Foreign currency translation adjustments 1 $ 6.7 $ 15.7 $ 1.1 Other expense, net Gains on available-for-sale securities 0.0 0.0 (0.7 ) Other expense, net Losses on derivative instruments 2.3 2.2 2.1 Interest expense Amortization of defined benefit pension and postretirement plans items 6.7 6.5 13.7 Other expense, net Tax effect (1.9 ) (2.3 ) (2.1 ) Provision for income taxes Total amount reclassified from accumulated other comprehensive loss, net of tax $ 13.8 $ 22.1 $ 14.1 1 These foreign currency translation adjustments are primarily a result of the sales of businesses.

Incentive Compensation Plans (N

Incentive Compensation Plans (Notes)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Incentive Compensation Plans	Incentive Compensation Plans 2019 & 2014 Performance Incentive Plan We issue stock-based compensation and cash awards to our employees under various plans established by the Compensation and Leadership Talent Committee of the Board of Directors (the “Compensation Committee”) and approved by our shareholders. In May 2019, our shareholders approved the 2019 Performance Incentive Plan (the “ 2019 PIP”), replacing the 2014 Performance Incentive Plan (the “2014 PIP”) and previous incentive plans. The number of shares of common stock initially available for grants of all equity awards under the 2019 PIP is 27.0 . Pursuant to the terms of the 2019 PIP, the number of shares that may be awarded to any one participant for any stock based awards is limited to 2.0 . The vesting period of awards granted is generally commensurate with the requisite service period. We generally issue new shares to satisfy the exercise of stock options or the distribution of other stock-based awards. Additionally, under the 2019 PIP, we have the ability to issue performance cash awards. The performance cash awards are granted to certain employees who otherwise would have been eligible to receive performance-based stock awards. These awards have a service period vesting condition and a performance vesting condition. The amount of the performance cash award received by an employee with a performance vesting condition can range from 0% to 300% of the target amount of the original grant value, except for Executive Officers of IPG, with a range of 0% to 200% . Performance cash awards generally vest in three years . The Compensation Committee may grant performance cash awards to any eligible employee; however, no employee can receive more than $10.0 during a performance period. The amounts of stock-based compensation expense as reflected in salaries and related expenses in our Consolidated Statements of Operations, and the related tax benefit, are listed below. Years ended December 31, 2019 2018 2017 Stock-settled awards $ 33.5 $ 24.7 $ 20.5 Cash-settled awards 0.8 0.6 1.0 Performance-based awards 46.7 57.5 61.5 Employee stock purchase plan 1.1 0.9 1.0 Other 1 0.6 0.9 0.5 Stock-based compensation expense $ 82.7 $ 84.6 $ 84.5 Tax benefit $ 20.0 $ 20.4 $ 30.4 1 Represents charges recorded for severance expense related to stock-based compensation awards. Stock Options Stock options are granted with the exercise price equal to the fair market value of our common stock on the grant date. We use the Black-Scholes option-pricing model to estimate the fair value of options granted, which requires the input of subjective assumptions including the option’s expected term and the price volatility of the underlying stock. They are generally first exercisable between two and four years from the grant date and expire ten years after the grant date (or earlier in the case of certain terminations of employment). There were no stock options granted during the years ended December 31, 2019 , 2018 and 2017 . As of December 31, 2019 , all stock options granted were fully vested and exercisable. The following table summarizes our stock option activity during 2019 . Options Weighted- Average Exercise Price (per option) Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Stock options outstanding as of January 1, 2019 1.8 $ 10.66 Exercised (0.6 ) $ 7.38 Stock options outstanding as of December 31, 2019 1.2 $ 12.26 2.7 $ 12.9 There were 0.6 , 1.9 and 1.1 stock options exercised in 2019 , 2018 and 2017 , respectively. The total intrinsic value of stock options exercised during 2019 , 2018 and 2017 was $9.1 , $27.9 and $15.1 , respectively. The cash received from the stock options exercised in 2019 , 2018 and 2017 was $8.3 , $29.0 and $20.0 , which included taxes withheld of $4.0 , $13.3 , and $6.8 , respectively. Stock-Based Compensation We grant other stock-based compensation awards such as stock-settled awards, cash-settled awards and performance-based awards (settled in cash or shares) to certain key employees. The number of shares or units received by an employee for performance-based awards depends on Company performance against specific performance targets and could range from 0% to 300% of the target amount of shares originally granted, except for Executive Officers of IPG, with a range of 0% to 200% . Incentive awards are subject to certain restrictions and vesting requirements as determined by the Compensation Committee. The fair value of the shares on the grant date is amortized over the vesting period, which is generally three years . Upon completion of the vesting period for cash-settled awards, the grantee is entitled to receive a payment in cash based on the fair market value of the corresponding number of shares of common stock. No monetary consideration is paid by a recipient for any incentive award. The fair value of cash-settled awards is adjusted each quarter based on our share price. The holders of stock-settled awards have absolute ownership interest in the underlying shares of common stock prior to vesting, which includes the right to vote and receive dividends. Dividends declared on common stock are accrued during the vesting period and paid when the award vests. The holders of performance-based awards have no ownership interest in the underlying shares of common stock until the awards vest and the shares of common stock are issued. Stock-based compensation awards expected to be settled in cash have been classified as liabilities in our Consolidated Balance Sheets as of December 31, 2019 and 2018 . Years ended December 31, 2019 2018 2017 Stock-Settled Awards: Awards granted 2.5 2.1 0.8 Weighted-average grant-date fair value (per award) $ 22.78 $ 23.60 $ 24.18 Total fair value of vested awards distributed $ 15.2 $ 24.2 $ 22.6 Cash-Settled Awards: Awards granted 0.0 0.1 0.0 Weighted-average grant-date fair value (per award) $ 22.83 $ 23.62 $ 23.33 Total fair value of vested awards distributed $ 0.9 $ 0.8 $ 0.9 Performance-Based Awards: Awards granted 2.1 2.9 4.8 Weighted-average grant-date fair value (per award) $ 20.16 $ 21.13 $ 20.06 Total fair value of vested awards distributed $ 64.9 $ 87.2 $ 112.4 In conjunction with common stock dividends declared in 2019 and 2018 , we accrued dividends of $4.2 and $2.4 , respectively, on non-vested stock-settled awards and paid dividends of $1.2 and $1.5 for stock-settled awards that vested during 2019 and 2018 , respectively. A summary of the activity of our non-vested stock-settled awards, cash-settled awards and performance-based awards during 2019 is presented below (performance-based awards are shown at 100% of the shares originally granted). Stock-Settled Awards Cash-Settled Awards Performance-Based Awards Awards Weighted- Average Grant-Date Fair Value (per award) Awards Weighted- Average Grant-Date Fair Value (per award) Awards Weighted- Average Grant-Date Fair Value (per award) Non-vested as of January 1, 2019 3.1 $ 23.51 0.1 $ 23.47 7.0 $ 21.10 Granted 2.5 22.78 0.0 22.83 2.1 20.16 Vested (0.7 ) 22.78 0.0 23.53 (2.9 ) 19.93 Forfeited (0.2 ) 23.42 0.0 22.84 (0.6 ) 21.01 Non-vested as of December 31, 2019 4.7 $ 23.21 0.1 $ 23.20 5.6 $ 21.36 Total unrecognized compensation expense remaining $ 56.0 $ 1.2 $ 45.7 Weighted-average years expected to be recognized over 1.6 1.5 1.7 In conjunction with our annual grant of long-term incentive compensation awards, we reviewed our estimates and assumptions in 2019 , which resulted in a forfeiture rate slightly less than prior years. 2009 Restricted Cash Plan In March 2009 , the Compensation Committee approved the Interpublic Restricted Cash Plan (the “Cash Plan”). Under the Cash Plan, the Board, the Compensation Committee or the Plan Administrator may grant cash awards to certain employees eligible to receive cash-settled awards. Cash awards, when granted, have a service-period vesting condition and generally vest in three years . Cash Awards During the years ended December 31, 2019 , 2018 and 2017 , the Compensation Committee granted cash awards under the Cash Plan with a total target value of $22.3 , $20.9 and $2.8 , respectively. For those same years, we recognized $15.6 , $7.0 and $2.5 , respectively, in salaries and related expenses in our Consolidated Statements of Operations. During the years ended December 31, 2019 , 2018 and 2017 , the Compensation Committee granted performance awards to be settled in cash under the 2019 PIP with a total target value of $40.7 , $39.9 , and $38.4 , respectively. For those same years, we recognized $39.9 , $37.6 and $35.3 , respectively, in salaries and related expenses in our Consolidated Statements of Operations. We amortize the present value of the amount expected to vest for cash awards and performance cash awards over the vesting period using the straight-line method, less an assumed forfeiture rate. Cash awards do not fall within the scope of the authoritative guidance for stock compensation as they are not paid in equity and the value of the award is not correlated with our stock price. Due to the cash nature of the payouts and the vesting period, we account for these awards in accordance with authoritative guidance for deferred compensation arrangements. Employee Stock Purchase Plans In May 2016, our shareholders approved The Interpublic Group of Companies Employee Stock Purchase Plan (2016) (the “ESPP”), replacing the prior employee stock purchase plan under which, prior to its expiration on December 31, 2015, 3.0 shares were issued. Under the ESPP, eligible employees may purchase our common stock through payroll deductions not exceeding 10% of their eligible compensation or 900 (actual number) shares each offering period, consistent with the prior employee stock purchase plan. The price an employee pays for a share of common stock under the ESPP is 90% of the lesser of the average market price of a share on the first business day of the offering period or the average market price of a share on the last business day of the offering period of three months . An aggregate of approximately 10.0 shares are reserved for issuance under the ESPP, of which 1.1 shares have been issued since the inception of the ESPP through December 31, 2019 .

Fair Value Measurements (Notes)

Fair Value Measurements (Notes)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Disclosures	Fair Value Measurements Authoritative guidance for fair value measurements establishes a fair value hierarchy which requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value: Level 1 Unadjusted quoted prices in active markets for identical assets or liabilities. An active market for the asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Financial Instruments that are Measured at Fair Value on a Recurring Basis We primarily apply the market approach to determine the fair value of financial instruments that are measured at fair value on a recurring basis. There were no changes to our valuation techniques used to determine the fair value of financial instruments during 2019 as compared to the prior year. The following tables present information about our financial instruments measured at fair value on a recurring basis as of December 31, 2019 and 2018 , and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. December 31, 2019 Balance Sheet Classification Level 1 Level 2 Level 3 Total Assets Cash equivalents $ 786.0 $ 0.0 $ 0.0 $ 786.0 Cash and cash equivalents Liabilities Contingent acquisition obligations 1 $ 0.0 $ 0.0 $ 114.1 $ 114.1 Accrued liabilities and Other non-current liabilities December 31, 2018 Balance Sheet Classification Level 1 Level 2 Level 3 Total Assets Cash equivalents $ 132.1 $ 0.0 $ 0.0 $ 132.1 Cash and cash equivalents Liabilities Contingent acquisition obligations 1 $ 0.0 $ 0.0 $ 148.4 $ 148.4 Accrued liabilities and Other non-current liabilities 1 Contingent acquisition obligations includes deferred acquisition payments and unconditional obligations to purchase additional noncontrolling equity shares of consolidated subsidiaries. Fair value measurement of the obligations is based upon actual and projected operating performance targets as specified in the related agreements. The decrease in this balance of $34.3 from December 31, 2018 to December 31, 2019 is primarily due to payments and a reclassification from an arrangement during the second quarter of 2019. The amounts payable within the next twelve months are classified in accrued liabilities; any amounts payable thereafter are classified in other non-current liabilities. Financial Instruments that are not Measured at Fair Value on a Recurring Basis The following table presents information about our financial instruments that are not measured at fair value on a recurring basis as of December 31, 2019 , and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. December 31, 2019 Level 1 Level 2 Level 3 Total Total long-term debt $ 0.0 $ 3,520.0 $ 45.5 $ 3,565.5 Our long-term debt is comprised of senior notes and other notes payable. The fair value of our senior notes, which are traded over-the-counter, is based on quoted prices in markets that are not active. Therefore, these senior notes are classified as Level 2 within the fair value hierarchy. Our other notes payable are not actively traded, and their fair value is not solely derived from readily observable inputs. The fair value of our other notes payable is determined based on a discounted cash flow model and other proprietary valuation methods, and therefore is classified as Level 3 within the fair value hierarchy. See Note 4 for further information on our long-term debt. Non-financial Instruments that are Measured at Fair Value on a Nonrecurring Basis Certain non-financial assets and liabilities are measured at fair value on a nonrecurring basis, primarily goodwill, intangible assets, and property and equipment. Accordingly, these assets are not measured and adjusted to fair value on an ongoing basis but are subject to periodic evaluations for potential impairment.

Employee Benefits (Notes)

Employee Benefits (Notes)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Employee Benefits	Employee Benefits Pension and Postretirement Benefit Plans We have a defined benefit pension plan covering certain U.S. employees (the “Domestic Pension Plan”) that consists of approximately 3,200 participants and is closed to new participants. We also have numerous funded and unfunded plans outside the U.S. The Interpublic Limited Pension Plan in the U.K. (the "U.K. Pension Plan") is a defined benefit plan and is our most material foreign pension plan in terms of the benefit obligation and plan assets. Some of our domestic and foreign subsidiaries provide postretirement health benefits and life insurance to eligible employees and, in certain cases, their dependents. The domestic postretirement benefit plan is our most material postretirement benefit plan in terms of the benefit obligation. This plan consists of approximately 1,500 participants, is closed to new participants and is unfunded. Differences between the aggregate income statement and balance sheet amounts listed in the tables below and the totals reported in our Consolidated Statements of Operations, Consolidated Statements of Comprehensive Income and Consolidated Balance Sheets relate to non-material foreign pension and postretirement benefit plans. Pension and Postretirement Benefit Obligation The change in the benefit obligation, the change in plan assets, the funded status and amounts recognized for the Domestic Pension Plan, the significant foreign pension plans and the domestic postretirement benefit plan are listed below. Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan 2019 2018 2019 2018 2019 2018 Benefit Obligation Projected benefit obligation as of January 1 $ 115.4 $ 125.4 $ 496.0 $ 582.3 $ 27.7 $ 31.8 Service cost 0.0 0.0 4.8 5.4 0.0 0.0 Interest cost 4.8 4.5 12.4 13.1 1.2 1.1 Benefits paid (9.2 ) (9.5 ) (27.8 ) (27.4 ) (5.4 ) (5.9 ) Plan participant contributions 0.0 0.0 0.0 0.1 2.0 1.8 Actuarial losses (gains) 5.9 (5.0 ) 42.7 (47.6 ) 1.7 (1.1 ) Settlements and curtailments 0.0 0.0 (0.7 ) (5.8 ) 0.0 0.0 Foreign currency effect 0.0 0.0 13.8 (26.4 ) 0.0 0.0 Other 0.0 0.0 0.0 2.3 0.0 0.0 Projected benefit obligation as of December 31 $ 116.9 $ 115.4 $ 541.2 $ 496.0 $ 27.2 $ 27.7 Fair Value of Plan Assets Fair value of plan assets as of January 1 $ 89.8 $ 98.8 $ 363.9 $ 404.2 $ 0.0 $ 0.0 Actual return on plan assets 16.1 (8.1 ) 42.0 (8.0 ) 0.0 0.0 Employer contributions 2.4 8.6 18.0 19.1 3.4 4.1 Plan participant contributions 0.0 0.0 0.0 0.1 2.0 1.8 Benefits paid (9.2 ) (9.5 ) (27.8 ) (27.4 ) (5.4 ) (5.9 ) Settlements 0.0 0.0 0.0 (4.6 ) 0.0 0.0 Foreign currency effect 0.0 0.0 13.4 (21.1 ) 0.0 0.0 Other 0.0 0.0 0.0 1.6 0.0 0.0 Fair value of plan assets as of December 31 $ 99.1 $ 89.8 $ 409.5 $ 363.9 $ 0.0 $ 0.0 Funded status of the plans at December 31 $ (17.8 ) $ (25.6 ) $ (131.7 ) $ (132.1 ) $ (27.2 ) $ (27.7 ) Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan December 31, 2019 2018 2019 2018 2019 2018 Amounts recognized in Consolidated Balance Sheets Non-current asset $ 0.0 $ 0.0 $ 10.1 $ 8.6 $ 0.0 $ 0.0 Current liability 0.0 0.0 (5.8 ) (6.2 ) (2.7 ) (2.9 ) Non-current liability (17.8 ) (25.6 ) (136.0 ) (134.5 ) (24.5 ) (24.8 ) Net liability recognized $ (17.8 ) $ (25.6 ) $ (131.7 ) $ (132.1 ) $ (27.2 ) $ (27.7 ) Accumulated benefit obligation $ 116.9 $ 115.4 $ 538.6 $ 493.2 Amounts recognized in Accumulated Other Comprehensive Loss, net Net actuarial loss $ 54.2 $ 60.4 $ 183.2 $ 165.6 $ 4.7 $ 3.1 Prior service cost (credit) 0.0 0.0 1.1 1.2 (0.1 ) (0.3 ) Total amount recognized $ 54.2 $ 60.4 $ 184.3 $ 166.8 $ 4.6 $ 2.8 Actuarial losses of $5.9 for the Domestic Pension Plan are attributed to a decrease in the discount rate from 4.35% as of December 31, 2018 to 3.35% as of December 31, 2019 , offset by changes in the mortality assumption and demographic experience. Actuarial losses of $42.7 for the foreign pension plans are attributed to a decrease in the weighted-average discount rate from 2.61% as of December 31, 2018 to 1.84% as of December 31, 2019 offset by changes in demographic experience. Domestic Pension Plan Foreign Pension Plans December 31, 2019 2018 2019 2018 Pension plans with an accumulated benefit obligation and projected benefit obligation in excess of plan assets Aggregate projected benefit obligation $ 116.9 $ 115.4 $ 534.6 $ 491.2 Aggregate accumulated benefit obligation 116.9 115.4 533.5 489.9 Aggregate fair value of plan assets 99.1 89.8 392.7 350.5 Net Periodic Cost The components of net periodic benefit cost and key assumptions are listed below. Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan Years ended December 31, 2019 2018 2017 2019 2018 2017 2019 2018 2017 Service cost $ 0.0 $ 0.0 $ 0.0 $ 4.8 $ 5.4 $ 4.9 $ 0.0 $ 0.0 $ 0.0 Interest cost 4.8 4.5 5.1 12.4 13.1 13.5 1.2 1.1 1.3 Expected return on plan assets (5.9 ) (6.6 ) (6.2 ) (17.4 ) (18.8 ) (17.7 ) 0.0 0.0 0.0 Settlement and curtailment (gains) losses 0.0 0.0 0.0 0.0 (1.0 ) 6.8 0.0 0.0 0.0 Amortization of: Prior service cost (credit) 0.0 0.0 0.0 0.1 0.1 0.1 (0.2 ) (0.2 ) (0.2 ) Net actuarial losses 1.9 1.6 1.5 4.8 5.9 5.5 0.1 0.1 0.0 Net periodic cost $ 0.8 $ (0.5 ) $ 0.4 $ 4.7 $ 4.7 $ 13.1 $ 1.1 $ 1.0 $ 1.1 Assumptions Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan Years ended December 31, 2019 2018 2017 2019 2018 2017 2019 2018 2017 Net periodic cost Discount rate 4.35 % 3.70 % 4.20 % 2.61 % 2.36 % 2.52 % 4.30 % 3.65 % 4.05 % Rate of compensation increase N/A N/A N/A 2.58 % 2.37 % 2.36 % N/A N/A N/A Expected return on plan assets 7.00 % 7.00 % 7.00 % 4.76 % 4.70 % 4.66 % N/A N/A N/A Interest crediting rates 5.10 % 5.10 % 5.10 % 1.44 % 1.31 % 1.29 % N/A N/A N/A Benefit obligation Discount rate 3.35 % 4.35 % 3.70 % 1.84 % 2.61 % 2.36 % 3.25 % 4.30 % 3.65 % Rate of compensation increase N/A N/A N/A 2.51 % 2.58 % 2.37 % N/A N/A N/A Interest crediting rates 5.10 % 5.10 % 5.10 % 1.37 % 1.44 % 1.31 % N/A N/A N/A Health care cost trend rate assumed for next year Initial rate (weighted-average) 7.00 % 6.25 % 6.50 % Year ultimate rate is reached 2028 2024 2024 Ultimate rate 5.00 % 5.00 % 5.00 % Discount Rates – At December 31, 2019 , 2018 and 2017 , we determined our discount rates for our domestic pension plan, foreign pension plans and domestic postretirement benefit plan based on either a bond selection/settlement approach or bond yield curve approach. Using the bond selection/settlement approach, we determine the discount rate by selecting a portfolio of corporate bonds appropriate to provide for the projected benefit payments. Using the bond yield curve approach, we determine the discount rate by matching the plans' cash flows to spot rates developed from a yield curve. Both approaches utilize high-quality AA-rated corporate bonds and the plans' projected cash flows to develop a discounted value of the benefit payments, which is then used to develop a single discount rate. In countries where markets for high-quality long-term AA corporate bonds are not well developed, a portfolio of long-term government bonds is used as a basis to develop hypothetical corporate bond yields, which serve as a basis to derive the discount rate. Expected Return on Assets – Our expected rate of return is determined at the beginning of each year and considers asset class index returns over various market and economic conditions, current and expected market conditions, risk premiums associated with asset classes and long-term inflation rates. We determine both a short-term and long-term view and then select a long-term rate of return assumption that matches the duration of our liabilities. Fair Value of Pension Plan Assets The following table presents the fair value of our domestic and foreign pension plan assets as of December 31, 2019 and 2018 , and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. See Note 13 for a description of the fair value hierarchy. December 31, 2019 December 31, 2018 Plan assets subject to fair value hierarchy Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Registered investment companies $ 18.0 $ 0.0 $ 0.0 $ 18.0 $ 13.0 $ 0.0 $ 0.0 $ 13.0 Limited partnerships 0.0 0.0 25.6 25.6 0.0 0.0 25.6 25.6 Fixed income securities 19.6 0.0 0.0 19.6 23.1 0.0 0.0 23.1 Insurance contracts 0.0 5.5 0.0 5.5 0.0 5.8 0.0 5.8 Other 27.8 0.0 0.0 27.8 20.0 0.0 0.0 20.0 Total plan assets, subject to leveling $ 65.4 $ 5.5 $ 25.6 $ 96.5 $ 56.1 $ 5.8 $ 25.6 $ 87.5 Plan assets measured at net asset value Other investments measured at net asset value 1 412.1 366.2 Total plan assets $ 508.6 $ 453.7 1 Certain investments that are measured at fair value using the net asset value per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy but are included to reconcile to the amounts presented in the fair value of plan assets table above. Registered investment companies, which are publicly traded, are primarily valued using recently reported sales prices. Limited partnerships are invested primarily in equity and fixed income securities. Fixed income securities include government and investment-grade corporate bonds. Insurance contracts are valued based on the cash surrender value of the contract. Other investments primarily include cash and cash equivalents, equity securities and derivatives. Other investments measured at net asset value include common/collective trusts, hedge funds and other commingled assets that are invested primarily in equity and fixed income securities. These investments are not publicly traded and are valued based on the net asset value of shares held by the plan at year end, which reflects the fair value of the underlying investments. The following table presents additional information about our significant foreign pension plan assets for which we utilize Level 3 inputs to determine fair value. Years ended December 31, Plan assets subject to fair value hierarchy, Level 3 2019 2018 Balance at beginning of period $ 25.6 $ 29.5 Actual return on plan assets 0.0 (3.9 ) Balance at end of period $ 25.6 $ 25.6 Asset Allocation The primary investment goal for our plans’ assets is to maximize total asset returns while ensuring the plans’ assets are available to fund the plans’ liabilities as they become due. The plans’ assets in aggregate and at the individual portfolio level are invested so that total portfolio risk exposure and risk-adjusted returns best achieve this objective. The aggregate amount of our own stock held as investment for our domestic and foreign pension funds is considered negligible relative to the total fund assets. As of December 31, 2019 , the weighted-average target and actual asset allocations relating to our domestic and foreign pension plans' assets are listed below. December 31, Asset Class 2020 Target Allocation 2019 2018 Alternative investments 1 25 % 25 % 26 % Equity securities 25 % 25 % 22 % Fixed income securities 20 % 19 % 21 % Liability driven investments 2 14 % 14 % 16 % Real estate 9 % 9 % 6 % Other 7 % 8 % 9 % Total 100 % 100 % 100 % 1 Alternative investments have the flexibility to dynamically invest across a broad range of asset classes including bonds, equity, cash, property and commodities. 2 Liability driven investment strategies use government bonds as well as derivative instruments to hedge a portion of the impact of interest rates and inflation movements on the long-term liabilities. Cash Flows During 2019 , we contributed $2.4 and $18.0 of cash to our domestic and foreign pension plans, respectively. For 2020 , we expect to contribute approximately $3.0 and $18.0 of cash to our domestic and foreign pension plans, respectively. The estimated future benefit payments expected to be paid are presented below. Years Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan 2020 $ 14.6 $ 21.7 $ 2.7 2021 8.0 19.8 2.6 2022 8.1 21.0 2.4 2023 7.6 21.9 2.2 2024 7.5 22.7 2.1 2025 - 2029 34.6 116.7 8.8 The estimated future payments for our domestic postretirement benefit plan are net of any estimated U.S. federal subsidies expected to be received under the Medicare Prescription Drug, Improvement and Modernization Act of 2003, which total no more than $0.3 in any individual year. Savings Plans We sponsor defined contribution plans (the “Savings Plans”) that cover substantially all domestic employees. The Savings Plans permit participants to make contributions on a pre-tax and/or after-tax basis and allow participants to choose among various investment alternatives. We match a portion of participant contributions based upon their years of service. Amounts expensed for the Savings Plans for 2019 , 2018 and 2017 were $61.2 , $52.6 and $47.2 , respectively. Expenses include a discretionary Company contribution of $8.1 , $6.7 and $3.6 offset by participant forfeitures of $5.6 , $5.8 and $4.6 in 2019 , 2018 and 2017 , respectively. In addition, we maintain defined contribution plans in various foreign countries and contributed $54.5 , $51.3 and $47.4 to these plans in 2019 , 2018 and 2017 , respectively. Deferred Compensation and Benefit Arrangements We have deferred compensation and benefit arrangements which (i) permit certain of our key officers and employees to defer a portion of their salary or incentive compensation or (ii) require us to contribute an amount to the participant’s account. These arrangements may provide participants with the amounts deferred plus interest upon attaining certain conditions, such as completing a certain number of years of service, attaining a certain age or upon retirement or termination. As of December 31, 2019 and 2018 , the deferred compensation and deferred benefit liability balance was $197.5 and $196.2 , respectively. Amounts expensed for deferred compensation and benefit arrangements in 2019 , 2018 and 2017 were $19.4 , $10.0 and $18.5 , respectively. We have purchased life insurance policies on participants' lives to assist in the funding of the related deferred compensation and deferred benefit liabilities. As of December 31, 2019 and 2018 , the cash surrender value of these policies was $178.2 and $177.3 , respectively. Long-Term Disability Plan We have a long-term disability plan which provides income replacement benefits to eligible participants who are unable to perform their job duties or any job related to his or her education, training or experience. As all income replacement benefits are fully insured, no related obligation is required as of December 31, 2019 and 2018 . In addition to income replacement benefits, plan participants may remain covered for certain health and life insurance benefits up to normal retirement age, and accordingly, we have recorded an obligation of $5.5 and $5.9 as of December 31, 2019 and 2018 , respectively.

Segment Information (Notes)

Segment Information (Notes)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information As of December 31, 2019 , we have two reportable segments: IAN and CMG. IAN is comprised of McCann Worldgroup, Foote, Cone & Belding ("FCB"), MullenLowe Group, Media, Data and Technology which includes IPG Mediabrands and Acxiom, our digital specialist agencies and our domestic integrated agencies. CMG is comprised of a number of our specialist marketing services offerings. We also report results for the "Corporate and other" group. Within IAN, our agencies provide a comprehensive array of global communications and marketing services, each offering a range of solutions for our clients. Our digital specialist agencies, including R/GA and Huge, provide digital capabilities and serve as key digital partners. In addition, our domestic integrated agencies, including Hill Holliday, Deutsch, Carmichael Lynch and Tierney, provide a full range of advertising, marketing communications services and/or marketing services and partner with our global operating divisions as needed. Media, Data and Technology offerings provide strategic media planning and buying services as well as data management and leading marketing technology services. IAN’s operating divisions share similar economic characteristics and are similar in other areas, specifically related to the nature of their services, the manner in which the services are provided and the similarity of their respective customers. CMG, which includes Weber Shandwick, DeVries, Golin, FutureBrand, Jack Morton and Octagon Worldwide, provides clients with diversified services, including public relations, meeting and event production, sports and entertainment marketing, corporate and brand identity, and strategic marketing consulting. CMG shares some similarities with service lines offered by IAN; however, on an aggregate basis, CMG has a higher proportion of arrangements for which they act as principal. Beginning in the first quarter of 2019, Acxiom's results are presented in IAN and the profitability measure employed by our chief operating decision maker for allocating resources to operating divisions and assessing operating division performance is segment EBITA. All segments follow the same accounting policies as those described in Note 1 . Corporate and other is primarily comprised of selling, general and administrative expenses. Selling, general and administrative expenses includes corporate office expenses as well as shared service center and certain other centrally managed expenses that are not fully allocated to operating divisions; salaries, long-term incentives, annual bonuses and other miscellaneous benefits for corporate office employees; professional fees related to internal control compliance, financial statement audits and legal, information technology and other consulting services that are engaged and managed through the corporate office; and rental expense for properties occupied by corporate office employees. A portion of centrally managed expenses is allocated to operating divisions based on a formula that uses the planned revenues of each of the operating units. Amounts allocated also include specific charges for information technology-related projects, which are allocated based on utilization. Summarized financial information concerning our reportable segments is shown in the following tables. Years ended December 31, 2019 2018 2017 Total Revenue: IAN $ 8,026.4 $ 7,556.1 $ 7,009.6 CMG 2,194.9 2,158.3 2,038.0 Total $ 10,221.3 $ 9,714.4 $ 9,047.6 Net revenue: IAN $ 7,348.2 $ 6,767.5 $ 6,266.7 CMG 1,276.9 1,264.1 1,206.8 Total $ 8,625.1 $ 8,031.6 $ 7,473.5 Segment EBITA: IAN $ 1,110.4 $ 1,042.1 $ 891.7 CMG 163.4 180.3 194.4 Corporate and other (101.8 ) (176.0 ) (126.6 ) Total $ 1,172.0 $ 1,046.4 $ 959.5 Amortization of acquired intangibles: IAN $ 81.6 $ 32.3 $ 16.6 CMG 4.4 5.3 4.5 Corporate and other 0.0 0.0 0.0 Total $ 86.0 $ 37.6 $ 21.1 Depreciation and amortization 1 : IAN $ 166.0 $ 136.8 $ 108.9 CMG 19.2 19.0 19.0 Corporate and other 7.3 9.5 8.1 Total $ 192.5 $ 165.3 $ 136.0 Capital expenditures: IAN $ 161.8 $ 143.9 $ 112.0 CMG 13.3 13.0 17.7 Corporate and other 23.4 20.2 26.2 Total $ 198.5 $ 177.1 $ 155.9 1 Excludes amortization of acquired intangibles. December 31, 2019 2018 Total assets: IAN $ 15,170.3 $ 13,867.9 CMG 1,710.4 1,516.7 Corporate and other 871.2 235.7 Total $ 17,751.9 $ 15,620.3 The following table presents the reconciliation of segment EBITA to Income before income taxes. Years ended December 31, 2019 2018 2017 IAN EBITA $ 1,110.4 $ 1,042.1 $ 891.7 CMG EBITA 163.4 180.3 194.4 Corporate and other EBITA (101.8 ) (176.0 ) (126.6 ) Less: consolidated amortization of acquired intangibles 86.0 37.6 21.1 Operating income 1,086.0 1,008.8 938.4 Total (expenses) and other income (207.7 ) (170.8 ) (97.6 ) Income before income taxes $ 878.3 $ 838.0 $ 840.8 Long-lived assets, including operating lease right-of-use assets and excluding intangible assets, are presented by major geographic area in the following table. Long-Lived Assets December 31, 2019 2018 Domestic $ 2,080.4 $ 892.9 International: United Kingdom 167.6 57.9 Continental Europe 149.7 57.9 Asia Pacific 240.9 121.7 Latin America 74.8 43.6 Other 130.4 45.7 Total International 763.4 326.8 Total Consolidated $ 2,843.8 $ 1,219.7 Property and equipment are allocated based upon physical location. Other assets and investments are allocated based on the location of the related operations.

Commitments and Contingencies (

Commitments and Contingencies (Notes)	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Guarantees We have guaranteed certain obligations of our subsidiaries relating principally to operating leases and uncommitted lines of credit of certain subsidiaries. As of December 31, 2019 and 2018, the amount of parent company guarantees on lease obligations was $739.1 and $824.5 , respectively, the amount of parent company guarantees primarily relating to uncommitted lines of credit was $293.8 and $349.1 , respectively, and the amount of parent company guarantees related to daylight overdrafts, primarily utilized to manage intra-day overdrafts due to timing of transactions under cash pooling arrangements without resulting in incremental borrowings, was $207.7 and $207.8 , respectively. In the event of non-payment by the applicable subsidiary of the obligations covered by a guarantee, we would be obligated to pay the amounts covered by that guarantee. As of December 31, 2019 , there were no material assets pledged as security for such parent company guarantees. Contingent Acquisition Obligations The following table details the estimated future contingent acquisition obligations payable in cash as of December 31, 2019 . 2020 2021 2022 2023 2024 Thereafter Total Deferred acquisition payments $ 45.7 $ 30.4 $ 7.4 $ 4.4 $ 2.4 $ 0.0 $ 90.3 Redeemable noncontrolling interests and call options with affiliates 1 26.2 37.9 32.4 6.2 2.5 0.2 105.4 Total contingent acquisition payments $ 71.9 $ 68.3 $ 39.8 $ 10.6 $ 4.9 $ 0.2 $ 195.7 1 We have entered into certain acquisitions that contain both redeemable noncontrolling interests and call options with similar terms and conditions. The estimated amounts listed would be paid in the event of exercise at the earliest exercise date. We have certain redeemable noncontrolling interests that are exercisable at the discretion of the noncontrolling equity owners as of December 31, 2019 . These estimated payments of $21.5 are included within the total payments expected to be made in 2020 , and will continue to be carried forward into 2021 or beyond until exercised or expired. Redeemable noncontrolling interests are included in the table at current exercise price payable in cash, not at applicable redemption value, in accordance with the authoritative guidance for classification and measurement of redeemable securities. The majority of these payments are contingent upon achieving projected operating performance targets and satisfying other conditions specified in the related agreements and are subject to revision in accordance with the terms of the respective agreements. See Note 6 for further information relating to the payment structure of our acquisitions. Legal Matters We are involved in various legal proceedings, and subject to investigations, inspections, audits, inquiries and similar actions by governmental authorities arising in the normal course of business. The types of allegations that arise in connection with such legal proceedings vary in nature, but can include claims related to contract, employment, tax and intellectual property matters. We evaluate all cases each reporting period and record liabilities for losses from legal proceedings when we determine that it is probable that the outcome in a legal proceeding will be unfavorable and the amount, or potential range, of loss can be reasonably estimated. In certain cases, we cannot reasonably estimate the potential loss because, for example, the litigation is in its early stages. While any outcome related to litigation or such governmental proceedings in which we are involved cannot be predicted with certainty, management believes that the outcome of these matters, individually and in the aggregate, will not have a material adverse effect on our financial condition, results of operations or cash flows.

Recent Accounting Standards (No

Recent Accounting Standards (Notes)	12 Months Ended
	Dec. 31, 2019
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Standards	Recent Accounting Standards Accounting pronouncements not listed below were assessed and determined to be not applicable or are expected to have minimal impact on our Consolidated Financial Statements. Leases In February 2016, the Financial Accounting Standards Board ("FASB") issued amended guidance on lease accounting. We adopted the standard using the modified retrospective approach with an effective date of January 1, 2019. Prior-year financial statements were not recast under the new standard. The adoption resulted in the presentation of a right-of-use asset and lease liability on our Consolidated Balance Sheet and corresponding impacts on our Consolidated Statement of Cash Flows, but did not have a significant impact on our Consolidated Statements of Operations. See Note 3 for further discussion on our adoption of the new leases standard. Current Expected Credit Losses In June 2016, the FASB issued amended guidance on the accounting for credit losses on certain types of financial instruments, including trade receivables. The new model uses a forward-looking expected loss method, as opposed to the incurred loss method in current U.S. GAAP, which will generally result in earlier recognition of allowances for losses. This amended guidance is effective beginning January 1, 2020. We do not expect the adoption to have a material impact on our Consolidated Financial Statements. Fair Value Measurement Disclosures In August 2018, the FASB issued amended disclosure requirements for fair value measurements by removing, modifying and adding certain disclosures. This amended guidance is effective beginning January 1, 2020. We do not expect the adoption to have a material impact on our Consolidated Financial Statements. Income Taxes In December 2019, the FASB issued amended guidance to simplify the accounting for income taxes by removing certain exceptions and amending certain sections of existing guidance under ASC 740. This amended guidance is effective January 1, 2021 with early adoption permitted as early as January 1, 2020. We are currently assessing the impact the adoption of the amended guidance will have on our Consolidated Financial Statements.

Results by Quarter (Unaudited)

Results by Quarter (Unaudited) (Notes)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information	Results by Quarter (Unaudited) Three Months Ended March 31, Three Months Ended June 30, Three Months Ended September 30, Three Months Ended December 31, 2019 2018 2019 2018 2019 2018 2019 2018 Revenue: Net revenue $ 2,004.8 $ 1,774.0 $ 2,125.9 $ 1,948.2 $ 2,061.4 $ 1,895.7 $ 2,433.0 $ 2,413.7 Billable expenses 356.4 395.1 394.3 443.6 376.7 401.8 468.8 442.3 Total Revenue 2,361.2 2,169.1 2,520.2 2,391.8 2,438.1 2,297.5 2,901.8 2,856.0 Operating Expenses: Salaries and related expenses 1,421.1 1,330.3 1,381.2 1,292.9 1,334.4 1,251.4 1,432.1 1,423.7 Office and other direct expenses 389.2 323.8 387.3 333.3 367.9 317.0 419.7 381.0 Billable expenses 356.4 395.1 394.3 443.6 376.7 401.8 468.8 442.3 Cost of services 2,166.7 2,049.2 2,162.8 2,069.8 2,079.0 1,970.2 2,320.6 2,247.0 Selling, general and administrative expenses 1 41.4 35.1 18.1 28.8 9.8 21.6 24.5 81.0 Depreciation and amortization 71.1 46.0 73.0 44.0 69.0 44.0 65.4 68.9 Restructuring Charges 2 31.8 0.0 2.1 0.0 0.0 0.0 0.0 0.0 Total operating expenses 2,311.0 2,130.3 2,256.0 2,142.6 2,157.8 2,035.8 2,410.5 2,396.9 Operating income 50.2 38.8 264.2 249.2 280.3 261.7 491.3 459.1 Other (expense) income, net 3 (6.9 ) (24.4 ) (3.8 ) (16.3 ) (7.4 ) (15.3 ) (24.8 ) (13.6 ) Total (expenses) and other income (48.9 ) (40.3 ) (47.7 ) (37.7 ) (47.6 ) (37.6 ) (63.5 ) (55.2 ) Provision for income taxes 4 10.5 12.7 43.6 63.6 64.6 60.7 86.1 62.2 Net (loss) income (9.5 ) (16.1 ) 172.8 147.8 168.4 163.5 342.2 342.5 Net (loss) income available to IPG common stockholders $ (8.0 ) $ (14.1 ) $ 169.5 $ 145.8 $ 165.6 $ 161.0 $ 328.9 $ 326.2 (Loss) earnings per share available to IPG common stockholders: Basic $ (0.02 ) $ (0.04 ) $ 0.44 $ 0.38 $ 0.43 $ 0.42 $ 0.85 $ 0.85 Diluted $ (0.02 ) $ (0.04 ) $ 0.43 $ 0.37 $ 0.42 $ 0.41 $ 0.84 $ 0.84 Dividends declared per common share $ 0.235 $ 0.210 $ 0.235 $ 0.210 $ 0.235 $ 0.210 $ 0.235 $ 0.210 1 The three months ended June 30, September 30 and December 31, 2018 included transaction costs of $1.4 , $11.0 , and $22.6 , respectively, related to the acquisition of Acxiom. See "Acquisitions" Note 6 for further information. 2 The three months ended March 31, 2019 and June 30, 2019 included restructuring charges of $31.8 and $2.1 , respectively. See "Restructuring Charges" Note 11 for further information. 3 The three months ended March 31, June 30, September 30 and December 31, 2019 included pre-tax net losses of $8.6 , $3.2 , $7.7 , and $23.9 , respectively, on sales of businesses. The three months ended March 31, June 30, September 30 and December 31, 2018 included pre-tax net losses of $24.4 , $19.8 , $5.8 , and $11.9 , respectively, on sales of businesses. 4 The three months ended June 30 and December 31, 2019 included a tax benefit of $13.9 related to the settlement of certain tax positions and $25.3 related to valuation allowance reversals, respectively. The three months ended December 31, 2018 included a tax benefit of $23.4

Subsequent Events (Notes)

Subsequent Events (Notes)	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events We announced on February 12, 2020 that our Board had declared a common stock cash dividend of $0.255 per share, payable on March 16, 2020 to holders of record as of the close of business on March 2, 2020.

Restructuring Charges (Notes)

Restructuring Charges (Notes)	12 Months Ended
	Dec. 31, 2019
Restructuring Charges [Abstract]
Restructuring and Related Activities Disclosure [Text Block]	Restructuring Charges In the first quarter of 2019, the Company implemented a cost initiative (the "2019 Plan") to better align our cost structure with our revenue primarily related to specific client losses occurring in 2018, the components of which are listed below. Years ended December 31, 2019 2018 2017 Severance and termination costs $ 22.0 $ 0.0 $ 0.0 Lease restructuring costs 11.9 0.0 (0.4 ) Total restructuring charges $ 33.9 $ 0.0 $ (0.4 ) Net restructuring charges were comprised of $27.6 at IAN and $5.6 at CMG for the year ended December 31, 2019 . All restructuring actions were identified and initiated by the end of the first quarter of 2019, with all actions substantially completed by the end of the second quarter of 2019 and we don't expect any further restructuring adjustments. During the year ended December 31, 2019, severance and termination costs related to a planned reduction in workforces of 627 employees. The employee groups affected include executive, regional and account management as well as administrative, creative and media production personnel. Cash payments of $20.4 were made during the year ended December 31, 2019 , with the remaining liability of $1.6 expected to be paid by the end of the first quarter of 2020. Lease impairment costs relate to the office spaces that were vacated as part of the 2019 Plan, which includes impairment on the right-of-use asset of operating leases, furniture, and leasehold improvements. Given the remaining lease terms involved, the lease obligation will be paid out over a period of several years, net of sublease income.

Leases (Notes)

Leases (Notes)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Lessee, Operating Leases [Text Block]	Leases Effective January 1, 2019, we adopted Accounting Standards Codification Topic 842, Leases , using the modified retrospective transition method. As such, we have recognized a right-of-use asset and a corresponding lease liability on our Consolidated Balance Sheet for virtually all of our leases with a term of more than twelve months. Prior-year financial statements were not recast under the new standard and, therefore, those amounts are not presented below. As an accounting policy, we have elected not to apply the recognition requirements to short-term leases, not to separate non-lease components from lease components, and have elected the package of transition provisions available for existing contracts, which allowed us to carry forward our historical assessments of (i) whether contracts are or contain leases, (ii) lease classification and (iii) initial direct costs. We do not have a material amount of finance leases and the majority of our operating leases, for which we serve as the lessee, consist primarily of real-estate property for our offices around the world. Both the asset and liability are measured at the present value of the future lease payments, with the asset being subject to adjustments such as initial direct costs, prepaid lease payments, and lease incentives. Many of our leases provide for renewal and/or termination options, as well as escalation clauses, which are also factored into our lease payments when appropriate. Our leases have remaining lease terms of 1 year to 20 years. The discount rate used to measure the lease asset and liability is determined at the beginning of the lease term using the rate implicit in the lease, if readily determinable, or using the Company's collateralized credit-adjusted borrowing rate. The following table presents information on our operating leases for the full year of 2019 . Twelve months ended Operating lease cost $ 325.2 Short-term lease cost 13.8 Sublease income (12.9 ) Total lease cost $ 326.1 Twelve months ended Cash paid for amounts included in the measurement of lease liabilities $ 334.1 Right-of-use assets obtained in exchange for lease liabilities $ 422.8 As of December 31, 2019 Weighted-average remaining lease term Eight years Weighted-average discount rate 4.26 % Our future payments of our operating leases as of December 31, 2019 are listed in the table below. Period Net Rent 2020 $ 333.5 2021 300.7 2022 267.5 2023 209.7 2024 183.5 Thereafter 716.1 Total future lease payments 2,011.0 Less: imputed interest 314.2 Present value of future lease payments 1,696.8 Less: current portion of operating leases 267.2 Non-current operating leases $ 1,429.6 Our future payments of our operating leases as of December 31, 2018 are listed in the table below. Period Rent Obligations Sublease Rental Income Net Rent 2019 $ 352.0 $ (7.7 ) $ 344.3 2020 324.3 (5.2 ) 319.1 2021 282.3 (2.2 ) 280.1 2022 242.5 (1.3 ) 241.2 2023 184.0 (0.6 ) 183.4 Thereafter 714.6 (0.5 ) 714.1 Total future lease payments $ 2,099.7 $ (17.5 ) $ 2,082.2 As of December 31, 2019 , we had additional operating leases that had not yet commenced with future lease payments of approximately $238.0 that will commence within the year 2020 and lease terms of 4 to 15 years.

Significant Accounting Polici_2

Significant Accounting Policies Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Basis of Presentation Cost of services is comprised of the expenses of our revenue-producing operating segments including salaries and related expenses, office and other direct expenses and billable expenses, as well as an allocation of the centrally managed expenses from Corporate. Office and other direct expenses include rent expense, professional fees, certain expenses incurred by our staff in servicing our clients and other costs directly attributable to client engagements. Selling, general and administrative expenses are primarily the unallocated expenses from Corporate, as disclosed further in Note 15 , excluding depreciation and amortization. Depreciation and amortization of the fixed assets and intangible assets of the Company is disclosed as a separate operating expense. Restructuring charges relate to the Company's implementation of a cost initiative to better align our cost structure with our revenue, as discussed further in Note 11 .

Significant Accounting Polici_3

Significant Accounting Policies Leases (Policies)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Lessee, Leases [Policy Text Block]	Leases Effective January 1, 2019, we adopted Accounting Standards Codification Topic 842, Leases ("ASC 842"), using the modified retrospective transition method. As such, we recognized a right-of-use asset and a corresponding lease liability on our Consolidated Balance Sheet for virtually all of our leases with a term of more than twelve months. Prior-year financial statements were not recast under the new standard. As an accounting policy, we have elected not to apply the recognition requirements to short-term leases, not to separate non-lease components from lease components, and have elected the package of transition provisions available for existing contracts, which allowed us to carry forward our historical assessments of (i) whether contracts are or contain leases, (ii) lease classification and (iii) initial direct costs. The adoption of ASC 842 resulted in operating lease right-of-use assets of $1,421.1 and operating lease liabilities of $1,544.4 as of January 1, 2019. We do not have a material amount of finance leases and the majority of our operating leases, for which we serve as the lessee, consist primarily of real-estate property for our offices around the world. Both the asset and liability are measured at the present value of the future lease payments, with the asset being subject to adjustments such as initial direct costs, prepaid lease payments, and lease incentives. Many of our leases provide for renewal and/or termination options, as well as escalation clauses, which are also factored into our lease payments when appropriate. Our leases have remaining lease terms of 1 year to 20 years. The discount rate used to measure the lease asset and liability is determined at the beginning of the lease term using the rate implicit in the lease, if readily determinable, or using the Company's collateralized credit-adjusted borrowing rate.

Significant Accounting Polici_4

Significant Accounting Policies Principles of Consolidation (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Consolidated Financial Statements include the accounts of the Company and its consolidated subsidiaries, some of which are not wholly owned. Investments in companies over which we do not have control, but have the ability to exercise significant influence, are accounted for using the equity method of accounting. Investments in companies over which we have neither control nor have the ability to exercise significant influence are recorded at cost, less any impairment, adjusted for subsequent observable price changes. All intercompany accounts and transactions have been eliminated in consolidation. We have consolidated certain entities meeting the definition of variable interest entities, and the inclusion of these entities does not have a material impact on our Consolidated Financial Statements.

Significant Accounting Polici_5

Significant Accounting Policies Reclassifications (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Reclassifications	Reclassifications Certain reclassifications and immaterial revisions have been made to prior-period financial statements to conform to the current-period presentation. Segment information for the prior period has been recast to conform to the current-period presentation.

Significant Accounting Polici_6

Significant Accounting Policies Use of Estimates (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires us to make judgments, assumptions and estimates that affect the amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the reporting date and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and assumptions.

Significant Accounting Polici_7

Significant Accounting Policies Revenue Recognition (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Revenue Recognition	Revenue Recognition Our revenues are primarily derived from the planning and execution of multi-channel advertising and communications, marketing services, including public relations, meeting and event production, sports and entertainment marketing, corporate and brand identity, strategic marketing consulting, and providing marketing data and technology services around the world. Most of our client contracts are individually negotiated and, accordingly, the terms of client engagements and the basis on which we earn fees and commissions vary significantly. Our contracts generally provide for termination by either party on relatively short notice, usually 30 to 90 days, although our data management contracts typically have non-cancelable terms of more than one year. Our payment terms vary by client, and the time between invoicing date and due date is typically not significant. We generally have the legally enforceable right to payment for all services provided through the end of the contract or termination date. We recognize revenue when we determine our customer obtains control of promised goods or services, in an amount that reflects the consideration which we expect to receive in exchange for those goods or services. To determine revenue recognition, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue as or when we satisfy the performance obligation. We only apply the five-step model to contracts when it is probable that IPG will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, we assess the goods or services promised within each contract and determine those that are distinct performance obligations. We then assess whether we act as an agent or a principal for each identified performance obligation and include revenue within the transaction price for third-party costs when we determine that we act as principal. We typically do not capitalize costs to obtain a contract as these amounts would generally be recognized over a period of one year or less. Net revenue, primarily consisting of fees, commissions and performance incentives, represents the amount of our gross billings excluding billable expenses charged to a client. Generally, our compensation is based on a negotiated fixed price, rate per hour, a retainer, commission or volume. The majority of our fees are recognized over time as services are performed, either utilizing a function of hours incurred and rates per hour, as compared to periodically updated estimates to complete, or ratably over the term of the contract. For certain less-frequent commission-based contracts which contain clauses allowing our clients to terminate the arrangement at any time for no compensation, revenue is recognized at a point in time, typically the date of broadcast or publication. We report revenue net of taxes assessed by governmental authorities that are directly imposed on our revenue-producing transactions. Contractual arrangements with clients may also include performance incentive provisions designed to link a portion of our revenue to our performance relative to mutually agreed-upon qualitative and/or quantitative metrics. Performance incentives are treated as variable consideration which is estimated at contract inception and included in revenue based on the most likely amount earned out of a range of potential outcomes. Our estimates are based on a combination of historical award experience, anticipated performance and our best judgment. These estimates are updated on a periodic basis and are not expected to result in a reversal of a significant amount of the cumulative revenue recognized. The predominant component of billable expenses are third-party vendor costs incurred for performance obligations where we have determined that we are acting as principal. These third-party expenses are generally billed back to our clients. Billable expenses also includes incidental costs incurred in the performance of our services including airfare, mileage, hotel stays, out-of-town meals and telecommunication charges. We record these billable expenses within total revenue with a corresponding offset to operating expenses. In international markets, we may receive rebates or credits from vendors based on transactions entered into on behalf of clients. Rebates and credits are remitted back to our clients in accordance with our contractual requirements or may be retained by us based on the terms of a particular client contract and local law. Amounts owed back to clients are recorded as a liability and amounts retained by us are recorded as revenue when earned. In certain international markets, our media contracts may allow clients to terminate our arrangement at any time for no compensation to the extent that media has not yet run. For those contracts, we do not recognize revenue until the media runs which is the point in time at which we have a legally enforceable right to compensation. Performance Obligations Our client contracts may include various goods and services that are capable of being distinct, are distinct within the context of the contract and are therefore accounted for as separate performance obligations. We allocate revenue to each performance obligation in the contract at inception based on its relative standalone selling price. Our advertising businesses include a wide range of services that involve the creation of an advertising idea, concept, campaign, or marketing strategy in order to promote the client’s brand ("creative services"), and to act as an agent to facilitate the production of advertisements by third-party suppliers ("production services”). Our clients can contract us to perform one or both of these services, as they can derive stand-alone benefit from each. Production services can include formatting creative material for different media and communication mediums including digital, large-scale reproduction such as printing and adaptation services, talent engagement and acquisition, television and radio production, and outdoor billboard production. Our contracts that include both services are typically explicit in the description of which activities constitute the creative advertising services and those that constitute the production services. Both the creative and production services are sold separately, the client can derive utility from each service on its own, we do not provide a significant service of integrating these activities into a bundle, the services do not significantly modify one another, and the services are not highly interrelated or interdependent. As such, we typically identify two performance obligations in the assessment of our advertising contracts. Our media businesses include services to formulate strategic media plans ("media planning services") and to act as an agent to purchase media (e.g. television and radio spots, outdoor advertising, digital banners, etc.) from vendors on their behalf ("media buying services"). Our contracts that include both services are typically explicit in the description of which activities constitute the planning services and those that constitute the buying services. Both the planning and buying services are sold separately, the client can derive utility from each service on its own, we do not provide a significant service of integrating these activities into a bundle, the services do not significantly modify one another, and the services are not highly interrelated or interdependent. As such, we typically identify two performance obligations in the assessment of our media contracts. Our events businesses include creative services related to the conception and planning of custom marketing events as well as activation services which entail the carrying out of the event, including, but not limited to, set-up, design and staffing. Additionally, our public relations businesses include a broad range of services, such as strategic planning, social media strategy and the monitoring and development of communication strategies, among others. While our contracts in these businesses may include some or all of these services, we typically identify only one performance obligation in the assessment of our events and public relations contracts as we provide a significant service of integrating the individual services into a combined service for which the customer has contracted. Our data and technology services businesses include data management, data and data strategy, identity resolution, and measurement and analytics products and services. While our contracts in these businesses may include some or all of these services, we typically identify each product and service as an individual performance obligation. We have elected not to disclose information about remaining performance obligations that have original expected durations of one year or less. The majority of our contracts are for periods of one year or less with the exception of our data management contracts. Principal vs. Agent When a third-party is involved in the delivery of our services to the client, we assess whether or not we are acting as a principal or an agent in the arrangement. The assessment is based on whether we control the specified services at any time before they are transferred to the customer. We have determined that in our events and public relations businesses, we generally act as a principal as our agencies provide a significant service of integrating goods or services provided by third parties into the specified deliverable to our clients. In addition, we have determined that we are responsible for the performance of the third-party suppliers, which are combined with our own services, before transferring those services to the customer. In addition, we have determined that we act as principal when providing creative services and media planning services, as we perform a significant integration service in these transactions. For performance obligations in which we act as principal, we record the gross amount billed to the customer within total revenue and the related incremental direct costs incurred as billable expenses. When a third-party is involved in the production of an advertising campaign and for media buying services, we have determined that we act as the agent and are solely arranging for the third-party to provide services to the customer. Specifically, we do not control the specified services before transferring those services to the customer, we are not primarily responsible for the performance of the third-party services, nor can we redirect those services to fulfill any other contracts. We do not have inventory risk or discretion in establishing pricing in our contracts with customers. For performance obligations for which we act as the agent, we record our revenue as the net amount of our gross billings less amounts remitted to third parties.

Significant Accounting Polici_8

Significant Accounting Policies Cash and Cash Equivalents (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents are highly liquid investments, which include certificates of deposit, government securities, commercial paper and time deposits with original maturities of three months or less at the time of purchase and are stated at estimated fair value, which approximates cost. Cash is maintained at multiple high-credit-quality financial institutions.

Significant Accounting Polici_9

Significant Accounting Policies Allowance for Doubtful Accounts (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The allowance for doubtful accounts is estimated based on the aging of accounts receivable, reviews of client credit reports, industry trends and economic indicators, as well as reviews of recent payment history for specific customers. The estimate is based largely on a formula-driven calculation but is supplemented with economic indicators and knowledge of potential write-offs of specific client accounts.

Significant Accounting Polic_10

Significant Accounting Policies Acounts Receivable, Billable to Clients (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Accounts Receivable, Billable to Clients	Accounts Receivable, Billable to Clients Accounts receivable, billable to clients are primarily comprised of production and media costs that have been incurred but have not yet been billed to clients, as well as fees that have been earned which have not yet been billed to clients. Unbilled amounts are presented in expenditures billable to clients regardless of whether they relate to our fees or production and media costs. A provision is made for unrecoverable costs as deemed appropriate.

Significant Accounting Polic_11

Significant Accounting Policies Accounts Payable (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Accounts Payable	Accounts Payable Accounts payable includes all operating payables, including those related to all media and production costs. These payables are due within one year.

Significant Accounting Polic_12

Significant Accounting Policies Investments (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Investments	Investments Equity investments with readily determinable fair values, other than those accounted for using the equity method of accounting, will be measured at fair value. We regularly review our investments to determine whether a significant event or change in circumstances has occurred that may impact the fair value of each investment, with changes to fair value recorded in earnings. We evaluate fair value based on specific information (valuation methodologies, estimates of appraisals, financial statements, etc.) in addition to quoted market price, if available. We consider all known quantitative and qualitative factors in determining if a decline in value of an investment has occurred.

Significant Accounting Polic_13

Significant Accounting Policies Derivatives (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Derivatives	Derivatives We are exposed to market risk related to interest rates, foreign currency rates and certain balance sheet items. From time to time we enter into derivative instruments for risk management purposes, and not for speculative purposes. All derivative instruments are recorded at fair value on our balance sheet. Changes in fair value are immediately included in earnings if the derivatives are not designated as a hedge instrument or if the derivatives do not qualify as effective hedges. For derivatives designated as hedge instruments, we evaluate for hedge accounting both at inception and throughout the hedge period. If a derivative is designated as a fair value hedge, then changes in the fair value of the derivative are offset against the changes in the fair value of the underlying hedged item. If a derivative is designated as a cash flow hedge, then the changes in the fair value of the derivative are recognized as a component of accumulated other comprehensive income and subsequently reclassified to earnings in our Consolidated Statement of Operations in the same period as the underlying hedged transaction affects earnings. If a derivative is a net investment hedge, then the changes in the fair value of the derivative are recognized in other comprehensive income in the same period as the change in fair value of the underlying hedged foreign investment.

Significant Accounting Polic_14

Significant Accounting Policies Property and Equipment (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Property and Equipment	Property and Equipment Furniture, equipment, leasehold improvements and buildings are stated at cost, net of accumulated depreciation. Furniture and equipment are depreciated generally using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 7 years for furniture and equipment, 10 to 35 years for buildings and the shorter of the useful life or the remaining lease term for leasehold improvements. Land is stated at cost and is not depreciated. We capitalize certain internal and external costs incurred to acquire or create internal use software, principally related to our enterprise resource planning (“ERP”) systems. Our ERP systems are stated at cost, net of accumulated amortization, and are amortized using the straight-line method over 10 years. All other internal use computer software are stated at cost, net of accumulated amortization and are amortized using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 7 years.

Significant Accounting Polic_15

Significant Accounting Policies Goodwill and Other Intangible Assets (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets We account for our business combinations using the acquisition accounting method, which requires us to determine the fair value of net assets acquired and the related goodwill and other intangible assets. Determining the fair value of assets acquired and liabilities assumed requires management's judgment and involves the use of significant estimates, including projections of future cash inflows and outflows, discount rates, asset lives and market multiples. Considering the characteristics of advertising, specialized marketing and communication services companies, our acquisitions usually do not have significant amounts of tangible assets, as the principal asset we typically acquire is creative talent. As a result, a substantial portion of the purchase price is allocated to goodwill and other intangible assets. We review goodwill as of October 1 st each year and whenever events or significant changes in circumstances indicate that the carrying value may not be recoverable. We evaluate the recoverability of goodwill at a reporting unit level. We have 12 reporting units that were subject to the 2019 annual impairment testing. Our annual impairment review as of October 1, 2019 did not result in an impairment charge for any of our reporting units. Intangible assets with indefinite useful lives are not amortized but are evaluated for impairment annually or more frequently if events or changes in circumstances indicate that impairment may exist. The Company first assesses qualitative factors to determine whether it is necessary to perform a quantitative impairment test for indefinite-lived intangible assets. Impairment exists if the fair value of the indefinite-lived intangible asset is less than the carrying value. Our annual impairment review as of October 1, 2019 did not result in an impairment charge for any of our intangible assets with indefinite useful lives. For reporting units not included in the qualitative assessment, or for any reporting units identified in the qualitative assessment as "more likely than not" that the fair value is less than its carrying value, the quantitative impairment test is performed. For our annual impairment test, we compare the respective fair value of our reporting units' equity to the carrying value of their net assets. The sum of the fair values of all our reporting units is also reconciled to our current market capitalization plus an estimated control premium. Goodwill allocated to a reporting unit whose fair value is equal to or greater than its carrying value is not impaired, and no further testing is required. Should the carrying amount for a reporting unit exceed its fair value, then the quantitative impairment test is failed and impaired goodwill is written down to its fair value with a charge to expense in the period the impairment is identified. The fair value of each reporting unit for 2019 and 2018 was estimated using a combination of the income approach, which incorporates the use of the discounted cash flow method, and the market approach, which incorporates the use of earnings and revenue multiples based on market data. We review intangible assets with definite lives subject to amortization whenever events or circumstances indicate that a carrying amount of an asset may not be recoverable. Recoverability of these assets is determined by comparing the carrying value of these assets to the estimated undiscounted future cash flows expected to be generated by these asset groups. These asset groups are impaired when their carrying value exceeds their fair value. Impaired intangible assets with definite lives subject to amortization are written down to their fair value with a charge to expense in the period the impairment is identified. Intangible assets with definite lives are amortized on a straight-line basis with estimated useful lives generally between 7 and 15 years. Events or circumstances that might require impairment testing include the loss of a significant client, the identification of other impaired assets within a reporting unit, loss of key personnel, the disposition of a significant portion of a reporting unit, significant decline in stock price or a significant adverse change in business climate or regulations.

Significant Accounting Polic_16

Significant Accounting Policies Foreign Currencies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Foreign Currencies	Foreign Currencies The functional currency of our foreign operations is generally their respective local currency. Assets and liabilities are translated at the exchange rates in effect at the balance sheet date, and revenues and expenses are translated at the average exchange rates during the period presented. The resulting translation adjustments are recorded as a component of accumulated other comprehensive loss in the stockholders’ equity section of our Consolidated Balance Sheets. Currency transaction gains or losses primarily arising from transactions in currencies other than the functional currency are included in office and general expenses. Foreign currency transactions resulted in a pre-tax loss of $5.3 for the year ended December 31, 2019 and pre-tax gains of $5.6 and $1.9 in for the years ended December 31, 2018 and 2017 , respectively. We monitor the currencies of countries in which we operate in order to determine if the country should be considered a highly inflationary environment. A currency is determined to be highly inflationary when there is cumulative inflation of approximately 100% or more over a three-year period. If this occurs the functional currency of that country is changed to our reporting currency, the U.S. Dollar, and foreign exchange gains or losses are recognized on all monetary transactions, assets and liabilities in currencies other than the U.S. Dollar until the currency is no longer considered highly inflationary.

Significant Accounting Polic_17

Significant Accounting Policies Income Taxes (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Income Taxes	Income Taxes The provision for income taxes includes U.S. federal, state, local and foreign taxes. Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be reversed. We evaluate the realizability of our deferred tax assets and establish a valuation allowance when it is “more likely than not” that all or a portion of the deferred tax assets will not be realized. We evaluate our tax positions using the “more likely than not” recognition threshold and then apply a measurement assessment to those positions that meet the recognition threshold. The factors used in assessing valuation allowances include all available evidence, such as past operating results, estimates of future taxable income and the feasibility of tax planning strategies. We have established tax reserves that we believe to be adequate in relation to the potential for additional assessments in each of the jurisdictions in which we are subject to taxation. We regularly assess the likelihood of additional tax assessments in those jurisdictions and adjust our reserves as additional information or events require.

Significant Accounting Polic_18

Significant Accounting Policies Redeemable Noncontrolling Interests (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Redeemable Noncontrolling Interests	Redeemable Noncontrolling Interests Many of our acquisitions include provisions under which the noncontrolling equity owners can require us to purchase additional interests in a subsidiary at their discretion. Payments for these redeemable noncontrolling interests may be contingent on projected operating performance and satisfying other conditions specified in the related agreements. These payments are also subject to revision in accordance with the terms of the agreements. We record these redeemable noncontrolling interests in “mezzanine equity” in our Consolidated Balance Sheets. Each reporting period, redeemable noncontrolling interests are reported at their estimated redemption value, but not less than their initial fair value. Any adjustment to the redemption value above initial value prior to exercise will also impact retained earnings or additional paid-in capital (“APIC”), but will not impact net income. Adjustments as a result of currency translation will affect the redeemable noncontrolling interest balance, but do not impact retained earnings or additional paid-in capital.

Significant Accounting Polic_19

Significant Accounting Policies Earnings Per Share (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Earnings Per Share	Earnings Per Share (“EPS”) Basic EPS available to IPG common stockholders equals net income available to IPG common stockholders divided by the weighted-average number of common shares outstanding for the applicable period. Diluted EPS equals net income available to IPG common stockholders divided by the weighted-average number of common shares outstanding, plus any additional common shares that would have been outstanding if potentially dilutive shares had been issued. Diluted EPS reflect the potential dilution that would occur if certain potentially dilutive securities were exercised. The potential issuance of common stock is assumed to occur at the beginning of the year (or at the time of issuance of the potentially dilutive instrument, if later) and the incremental shares are included using the treasury stock method. The proceeds utilized in applying the treasury stock method consist of the amount, if any, to be paid upon exercise and, as it relates to stock-based compensation, the amount of compensation cost attributed to future service not yet recognized. These proceeds are then assumed to be used to purchase common stock at the average market price of our stock during the period. The incremental shares (difference between the shares assumed to be issued and the shares assumed to be purchased), to the extent they would have been dilutive, are included in the denominator of the diluted EPS calculation. We may be required to calculate basic EPS using the two-class method as a result of our redeemable noncontrolling interests. To the extent that the redemption value increases and exceeds the then-current fair value of a redeemable noncontrolling interest, net income available to IPG common stockholders (used to calculate EPS) could be negatively impacted by that increase, subject to certain limitations. The partial or full recovery of any reductions to net income available to IPG common stockholders (used to calculate EPS) is limited to any cumulative prior-period reductions. For the years ended December 31, 2019 , 2018 and 2017 , there was no impact to EPS for adjustments related to our redeemable noncontrolling interests.

Significant Accounting Polic_20

Significant Accounting Policies Pension and Postretirement Benefits (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Pension and Postretirement Benefits	Pension and Postretirement Benefits We have pension and postretirement benefit plans covering certain domestic and international employees. We use various actuarial methods and assumptions in determining our net pension and postretirement benefit costs and obligations, including the discount rate used to determine the present value of future benefits, expected long-term rate of return on plan assets and healthcare cost trend rates. The overfunded or underfunded status of our pension and postretirement benefit plans is recorded on our Consolidated Balance Sheet.

Significant Accounting Polic_21

Significant Accounting Policies Stock-Based Compensation (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Stock-Based Compensation	Stock-Based Compensation Compensation costs related to share-based transactions, including employee stock options, are recognized in the Consolidated Financial Statements based on fair value. Stock-based compensation expense is generally recognized ratably over the requisite service period based on the estimated grant-date fair value, net of estimated forfeitures.

Significant Accounting Polic_22

Significant Accounting Policies Treasury Stock (Policies)	12 Months Ended
	Dec. 31, 2019
Treasury Stock, Shares [Abstract]
Treasury Stock [Text Block]	Treasury Stock We account for repurchased common stock under the cost method and include such treasury stock as a component of our Consolidated Statements of Stockholders' Equity. Upon retirement, we reduce common stock for the par value of the shares being retired and the excess of the cost of the shares over par value as a reduction to APIC, to the extent there is APIC in the same class of stock, and any remaining amount to retained earnings. These retired shares remain authorized but unissued. During 2019 , there was no significant treasury stock activity due to the suspension of the share repurchase program, as disclosed further in Note 7 . In October 2018 , we retired 8.1 shares of our treasury stock, which resulted in a reduction in common stock of $0.8 , treasury stock of $176.1 and APIC of $175.3 . In October and November 2017 , we retired 13.4 shares of our treasury stock, which resulted in a reduction in common stock of $1.3 , treasury stock of $304.4 and APIC of $303.1 .

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue from External Customers by Geographic Areas [Table Text Block]	Years ended December 31, Total revenue: 2019 2018 2017 United States $ 6,368.7 $ 5,851.0 $ 5,417.3 International: United Kingdom 871.8 881.4 775.7 Continental Europe 842.9 840.2 780.6 Asia Pacific 1,102.3 1,170.8 1,106.4 Latin America 431.6 389.0 386.6 Other 604.0 582.0 581.0 Total International 3,852.6 3,863.4 3,630.3 Total Consolidated $ 10,221.3 $ 9,714.4 $ 9,047.6 Years ended December 31, Net revenue: 2019 2018 2017 United States $ 5,386.1 $ 4,825.0 $ 4,458.8 International: United Kingdom 727.0 711.7 613.1 Continental Europe 742.4 737.5 687.8 Asia Pacific 858.3 896.8 866.9 Latin America 389.9 350.1 350.8 Other 521.4 510.5 496.1 Total International 3,239.0 3,206.6 3,014.7 Total Consolidated $ 8,625.1 $ 8,031.6 $ 7,473.5 IAN Years ended December 31, Total revenue: 2019 2018 2017 United States $ 4,912.5 $ 4,447.0 $ 4,062.3 International 3,113.9 3,109.1 2,947.3 Total IAN $ 8,026.4 $ 7,556.1 $ 7,009.6 Net revenue: United States $ 4,557.5 $ 4,000.4 $ 3,660.6 International 2,790.7 2,767.1 2,606.1 Total IAN $ 7,348.2 $ 6,767.5 $ 6,266.7 CMG Years ended December 31, Total revenue: 2019 2018 2017 United States $ 1,456.2 $ 1,404.0 $ 1,355.0 International 738.7 754.3 683.0 Total CMG $ 2,194.9 $ 2,158.3 $ 2,038.0 Net revenue: United States $ 828.6 $ 824.6 $ 798.2 International 448.3 439.5 408.6 Total CMG $ 1,276.9 $ 1,264.1 $ 1,206.8
Contract with Customer, Asset and Liability [Table Text Block]	Contract Balances The following table provides information about receivables, contract assets and contract liabilities from contracts with customers. December 31, December 31, Accounts receivable, net of allowance of $40.2 and $42.5, respectively $ 5,209.2 $ 5,126.6 Accounts receivable, billable to clients 1,934.1 1,900.6 Contract assets 63.0 67.9 Contract liabilities (deferred revenue) 585.6 533.9

Debt and Credit Agreements Sche

Debt and Credit Agreements Schedule of Long-term Debt Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	A summary of the carrying amounts and fair values of our long-term debt is listed below. Effective Interest Rate December 31, 2019 2018 Book Value Fair Value 1 Book Value Fair 1 3.50% Senior Notes due 2020 (less unamortized discount and issuance costs of $0.4 and $1.1, respectively) 3.89 % $ 498.5 $ 505.4 $ 496.6 $ 499.9 3.75% Senior Notes due 2021 (less unamortized discount and issuance costs of $0.2 and $1.9, respectively) 3.98 % 497.9 513.5 496.8 503.2 4.00% Senior Notes due 2022 (less unamortized discount and issuance costs of $0.7 and $0.6, respectively) 4.13 % 248.7 258.8 248.2 250.3 3.75% Senior Notes due 2023 (less unamortized discount and issuance costs of $0.5 and $1.3, respectively) 4.32 % 498.2 522.8 497.7 491.4 4.20% Senior Notes due 2024 (less unamortized discount and issuance costs of $0.4 and $1.8, respectively) 4.24 % 497.8 538.1 497.3 492.6 4.65% Senior Notes due 2028 (less unamortized discount and issuance costs of $1.5 and $3.9, respectively) 4.78 % 494.6 564.3 494.0 494.1 5.40% Senior Notes due 2048 (less unamortized discount and issuance costs of $2.7 and $5.4, respectively) 5.48 % 491.9 617.1 491.7 474.1 Term Loan due 2021 - LIBOR plus 1.25% — — 400.0 400.0 Other notes payable and capitalized leases 46.3 45.5 38.0 38.0 Total long-term debt 3,273.9 3,660.3 Less: current portion 502.0 0.1 Long-term debt, excluding current portion $ 2,771.9 $ 3,660.2 1 See Note 13 for information on the fair value measurement of our long-term debt.

Debt and Credit Agreements Sc_2

Debt and Credit Agreements Schedule of Maturities of Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Long-term Debt, Fiscal Year Maturity [Abstract]
Schedule of Maturities of Long-term Debt [Table Text Block]	Annual maturities are scheduled as follows based on the book value as of December 31, 2019 . 2020 $ 502.0 2021 501.4 2022 248.9 2023 498.3 2024 497.8 Thereafter 1,025.5 Total long-term debt $ 3,273.9

Debt and Credit Agreements Sc_3

Debt and Credit Agreements Schedule of Financial Covenants in Credit Agreement (Tables)	12 Months Ended
	Dec. 31, 2019
Schedule of Line of Credit Facility [Abstract]
Schedule of Financial Covenants in Credit Agreement [Table Text Block]	In addition to other and customary covenants, we are required to maintain the financial covenant listed below as of the end of each fiscal quarter for the period of four fiscal quarters then ended pursuant to our Credit Agreement. We were in compliance with our covenant in the Credit Agreement as of December 31, 2019 . Financial Covenants 1 Leverage ratio (not greater than): 1 3.75x 1 The leverage ratio is defined as debt as of the last day of such fiscal quarter to EBITDA, as defined in the Credit Agreement, for the four quarters then ended. Pursuant to July 2018 Amendment No. 1 to the Credit Agreement, the maximum leverage ratio decreased from 4.00x to 3.75x on the last day of the fourth full fiscal quarter ending after the Acxiom closing date on October 1, 2018.

Earnings Per Share Basic and Di

Earnings Per Share Basic and Diluted Earnings Per Common Share Available to IPG Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Common Share Available to IPG Common Stockholders	The following sets forth basic and diluted earnings per common share available to IPG common stockholders. Years ended December 31, 2019 2018 2017 Net income available to IPG common stockholders $ 656.0 $ 618.9 $ 554.4 Weighted-average number of common shares outstanding - basic 386.1 383.3 389.6 Dilutive effect of stock options and restricted shares 5.1 5.7 7.7 Weighted-average number of common shares outstanding - diluted 391.2 389.0 397.3 Earnings per share available to IPG common stockholders: Basic $ 1.70 $ 1.61 $ 1.42 Diluted $ 1.68 $ 1.59 $ 1.40

Acquisitions Cash Paid for Curr

Acquisitions Cash Paid for Current and Prior Years' Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Cash Paid For Current And Prior Years' Acquisitions [Table Text Block]	Details of cash paid for current and prior years' acquisitions are listed below. Years ended December 31, 2019 2018 2017 Cost of investment: current-year acquisitions 1 $ 0.6 $ 2,323.4 $ 36.8 Cost of investment: prior-year acquisitions 15.8 33.9 54.6 Less: net cash acquired — (13.8 ) (7.1 ) Total cost of investment 16.4 2,343.5 84.3 Operating payments 2 9.3 19.4 47.1 Total cash paid for acquisitions 3 $ 25.7 $ 2,362.9 $ 131.4 1 The cost of investment: current-year acquisitions line significantly increased in the year ended December 31, 2018, primarily as a result of payments related to the acquisition of Acxiom. 2 Represents cash payments for amounts that have been recognized in operating expenses since the date of acquisition either relating to adjustments to estimates in excess of the initial value of contingent payments recorded or were contingent upon the future employment of the former owners of the acquired companies. Amounts are reflected in the operating section of the Consolidated Statements of Cash Flows. 3 Of the total cash paid for acquisitions, $0.6 , $2,309.8 and $30.6 for the years ended December 31, 2019 , 2018 and 2017 , respectively, are classified under the investing section of the Consolidated Statements of Cash Flows as acquisitions, net of cash acquired. These amounts relate to initial payments for new transactions. Of the total cash paid for acquisitions, $15.8 , $33.7 and $53.7 for the years ended December 31, 2019 , 2018 and 2017 , respectively, are classified under the financing section of the Consolidated Statements of Cash Flows as acquisition-related payments. These amounts relate to deferred payments and increases in our ownership interest for prior acquisitions.

Acquisitions Redeemable Noncont

Acquisitions Redeemable Noncontrolling Interest (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Redeemable Noncontrolling Interest	The following table presents changes in our redeemable noncontrolling interests. Years ended December 31, 2019 2018 2017 Balance at beginning of period $ 167.9 $ 252.1 $ 252.8 Change in related noncontrolling interests balance (2.8 ) (10.7 ) (2.8 ) Changes in redemption value of redeemable noncontrolling interests: Additions 24.3 0.0 7.7 Redemptions and other (24.9 ) (33.7 ) (18.5 ) Redemption value adjustments 0.2 (39.8 ) 12.9 Balance at end of period $ 164.7 $ 167.9 $ 252.1

Supplementary Data Valuation an

Supplementary Data Valuation and Qualifying Accounts - Allowance for Uncollectible Accounts (Tables)	12 Months Ended
	Dec. 31, 2019
Valuation and Qualifying Accounts - Allowance for Uncollectible Accounts [Abstract]
Valuation and Qualifying Accounts - Allowance for Uncollectible Accounts Receivable	Valuation and Qualifying Accounts – Allowance for Uncollectible Accounts Receivable Years ended December 31, 2019 2018 2017 Balance at beginning of period $ 42.5 $ 42.7 $ 55.7 Charges to costs and expenses 10.1 6.5 9.5 Adjustments: Acquisitions/(dispositions) (0.3 ) 2.2 (1.0 ) Uncollectible accounts written off (11.9 ) (7.1 ) (25.5 ) Foreign currency translation adjustments (0.2 ) (1.8 ) 4.0 Balance at end of period $ 40.2 $ 42.5 $ 42.7

Supplementary Data Property and

Supplementary Data Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property and Equipment [Abstract]
Property, Plant and Equipment [Table Text Block]	Property and Equipment December 31, 2019 2018 Furniture and equipment $ 694.3 $ 681.7 Leasehold improvements 634.9 629.0 Internal-use computer software 422.0 368.5 Land and buildings 143.3 146.6 Gross property and equipment 1,894.5 1,825.8 Less: accumulated depreciation and amortization (1,116.4 ) (1,034.9 ) Total property and equipment, net $ 778.1 $ 790.9

Supplementary Data Accrued Liab

Supplementary Data Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Accrued Liabilities [Abstract]
Schedule of Accrued Liabilities [Table Text Block]	Accrued Liabilities The following table presents the components of accrued liabilities. December 31, 2019 2018 Salaries, benefits and related expenses $ 494.1 $ 494.9 Acquisition obligations 45.7 65.7 Office and related expenses 26.9 52.2 Interest 38.8 43.6 Restructuring charges 1.6 0.0 Other 135.7 150.5 Total accrued liabilities $ 742.8 $ 806.9

Supplementary Data Other Expens

Supplementary Data Other Expense, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Other Nonoperating Income (Expense) [Abstract]
Schedule of Other Nonoperating Income (Expense) [Table Text Block]	Other Expense, Net Results of operations include certain items that are not directly associated with our revenue-producing operations. Years ended December 31, 2019 2018 2017 Net losses on sales of businesses $ (43.4 ) $ (61.9 ) $ (24.1 ) Other 0.5 (7.7 ) (2.1 ) Total other expense, net $ (42.9 ) $ (69.6 ) $ (26.2 )

Supplementary Data Share Repurc

Supplementary Data Share Repurchase Program (Tables)	12 Months Ended
	Dec. 31, 2019
Share Repurchase Program [Abstract]
Share Repurchase Program [Table Text Block]

Supplementary Data Supplemental

Supplementary Data Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	Supplemental Cash Flow Information Years ended December 31, 2019 2018 2017 Cash paid for interest $ 192.7 $ 88.7 $ 82.3 Cash paid for income taxes, net of refunds 1 150.2 207.9 228.4 1 Refunds of $92.6 , $24.3 and $31.9 were received for the years ended December 31, 2019 , 2018 and 2017 , respectively.

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets Changes in Carrying Value of Goodwill (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Value of Goodwill	The changes in the carrying value of goodwill for our segments, IAN and CMG, for the years ended December 31, 2019 and 2018 are listed below. IAN 1 CMG Total 2 Balance as of December 31, 2017 $ 3,161.8 $ 658.6 $ 3,820.4 Acquisitions 1,112.0 20.0 1,132.0 Foreign currency and other (64.5 ) (12.0 ) (76.5 ) Balance as of December 31, 2018 $ 4,209.3 $ 666.6 $ 4,875.9 Acquisitions 2.1 0.7 2.8 Foreign currency and other 14.4 1.3 15.7 Balance as of December 31, 2019 $ 4,225.8 $ 668.6 $ 4,894.4

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets Summary of Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Summary of Other Intangible Assets [Abstract]
Schedule of Finite-Lived Intangible Assets [Table Text Block]	The following table provides a summary of other intangible assets, which are included in our Consolidated Balance Sheets. December 31, 2019 2018 Gross Amount Accumulated Amortization Net Amount Gross Amount Accumulated Amortization Net Amount Customer lists $ 861.4 $ (244.6 ) $ 616.8 $ 857.2 $ (190.9 ) $ 666.3 Know-how and technology 235.0 (32.9 ) 202.1 235.0 (6.5 ) 228.5 Trade names 226.2 (41.3 ) 184.9 226.2 (36.8 ) 189.4 Other 14.3 (3.8 ) 10.5 14.3 (3.8 ) 10.5 Total $ 1,336.9 $ (322.6 ) $ 1,014.3 $ 1,332.7 $ (238.0 ) $ 1,094.7

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets Estimated future amortization of other intangible assets (Tables)	12 Months Ended
	Dec. 31, 2019
Summary of Other Intangible Assets [Abstract]
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	The estimated annual amortization expense for other intangible assets for the next five years as of December 31, 2019 is listed below. 2020 2021 2022 2023 2024 Estimated amortization expense $ 88.4 $ 86.9 $ 82.9 $ 78.6 $ 76.8

Income Taxes Schedule of Income

Income Taxes Schedule of Income before Income Tax, Domestic and Foreign (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The components of income before income taxes are listed below. Years ended December 31, 2019 2018 2017 Domestic $ 557.4 $ 474.0 $ 514.8 Foreign 320.9 364.0 326.0 Total $ 878.3 $ 838.0 $ 840.8

Income Taxes Schedule of Compon

Income Taxes Schedule of Components of Provision for Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The provision for income taxes is listed below. Years ended December 31, 2019 2018 2017 U.S. federal income taxes (including foreign withholding taxes): Current $ 92.2 $ 38.1 $ 154.1 Deferred 9.5 29.9 (37.6 ) 101.7 68.0 116.5 State and local income taxes: Current 10.7 25.1 18.8 Deferred 8.7 3.4 19.7 19.4 28.5 38.5 Foreign income taxes: Current 92.2 121.9 107.9 Deferred (8.5 ) (19.2 ) 8.4 83.7 102.7 116.3 Total $ 204.8 $ 199.2 $ 271.3

Income Taxes Schedule of Effect

Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of the effective income tax rate as reflected in our Consolidated Statements of Operations to the U.S. federal statutory income tax rate is listed below. Years ended December 31, 2019 2018 2017 U.S. federal statutory income tax rate 21.0 % 21.0 % 35.0 % Income tax provision at U.S. federal statutory rate $ 184.5 $ 176.0 $ 294.3 State and local income taxes, net of U.S. federal income tax benefit 14.0 23.8 23.5 Impact of foreign operations, including withholding taxes 34.2 50.7 (6.7 ) U.S. tax incentives (21.4 ) (17.5 ) (1.3 ) Change in net valuation allowance 1 (26.3 ) (16.9 ) 1.4 Divestitures 9.6 11.7 1.1 U.S. federal tax credits 0.4 (48.1 ) (0.4 ) Stock compensation (3.3 ) (6.8 ) (15.3 ) Increase in unrecognized tax benefits 14.1 8.4 7.0 Net impact of the Tax Act 0.0 13.4 (36.0 ) Other (1.0 ) 4.5 3.7 Provision for income taxes $ 204.8 $ 199.2 $ 271.3 Effective income tax rate on operations 23.3 % 23.8 % 32.3 % 1 Reflects changes in valuation allowances that impacted the effective income tax rate for each year presented.

Income Taxes Schedule of Deferr

Income Taxes Schedule of Deferred Tax Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	The components of deferred tax assets and liabilities are listed below. December 31, 2019 2018 Postretirement/post-employment benefits $ 16.7 $ 17.9 Deferred compensation 99.5 99.8 Pension costs 23.7 22.2 Basis differences in fixed assets (75.3 ) (71.7 ) Rent — 27.3 Interest 45.5 48.8 Accruals and reserves 19.4 21.0 Allowance for doubtful accounts 6.5 7.4 Basis differences in intangible assets (321.0 ) (302.7 ) Investments in equity securities 0.3 1.2 Operating lease right-of-use assets (335.2 ) — Operating lease liabilities 361.4 — Tax loss/tax credit carry forwards 297.1 345.6 Prepaid expenses (6.7 ) (6.3 ) Deferred revenue (21.7 ) (26.8 ) Unremitted foreign earnings (1.3 ) (9.5 ) Other 44.5 38.2 Total deferred tax assets, net 153.4 212.4 Valuation allowance (164.2 ) (211.0 ) Net deferred tax (liabilities) assets $ (10.8 ) $ 1.4

Income Taxes Summary of Valuati

Income Taxes Summary of Valuation Allowance (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Summary of Valuation Allowance [Table Text Block]	The change in the valuation allowance is listed below. Years ended December 31, 2019 2018 2017 Balance at beginning of period $ 211.0 $ 243.0 $ 255.6 Reversed to costs and expenses (24.9 ) (28.0 ) (4.6 ) (Reversed) charged to gross tax assets and other accounts 1 (19.8 ) 5.1 (27.3 ) Foreign currency translation (2.1 ) (9.1 ) 19.3 Balance at end of period $ 164.2 $ 211.0 $ 243.0

Income Taxes Schedule of Unreco

Income Taxes Schedule of Unrecognized Tax Benefits Activity (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Unrecognized Tax Benefits Activity [Table Text Block]	The table below summarizes the activity related to our unrecognized tax benefits. Years ended December 31, 2019 2018 2017 Balance at beginning of period $ 335.4 $ 271.9 $ 246.7 Increases as a result of tax positions taken during a prior year 22.7 65.9 6.3 Decreases as a result of tax positions taken during a prior year (25.8 ) (10.8 ) (8.1 ) Settlements with taxing authorities (8.1 ) (6.5 ) (0.8 ) Lapse of statutes of limitation (0.6 ) (1.7 ) (3.3 ) Increases as a result of tax positions taken during the current year 21.7 16.6 31.1 Balance at end of period $ 345.3 $ 335.4 $ 271.9

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss, Net of Tax Schedule of Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2019
Accumulated Other Comprehensive Loss [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table presents the changes in accumulated other comprehensive loss, net of tax, by component. Foreign Currency Translation Adjustments Derivative Instruments Defined Benefit Pension and Other Postretirement Plans Total Balance as of December 31, 2017 $ (585.3 ) $ (6.8 ) $ (235.7 ) $ (827.8 ) Other comprehensive (loss) income before reclassifications (146.8 ) 0.0 11.4 (135.4 ) Amount reclassified from accumulated other comprehensive loss, net of tax 15.7 1.5 4.9 22.1 Balance as of December 31, 2018 $ (716.4 ) $ (5.3 ) $ (219.4 ) $ (941.1 ) Other comprehensive income (loss) before reclassifications 12.0 0.0 (14.7 ) (2.7 ) Amount reclassified from accumulated other comprehensive loss, net of tax 6.7 1.8 5.3 13.8 Balance as of December 31, 2019 $ (697.7 ) $ (3.5 ) $ (228.8 ) $ (930.0 )

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss, Net of Tax Reclassification out of Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2019
Accumulated Other Comprehensive Loss [Abstract]
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	Amounts reclassified from accumulated other comprehensive loss, net of tax, for the years ended December 31, 2019 , 2018 and 2017 are as follows: Years ended December 31, Affected Line Item in the Consolidated Statements of Operations 2019 2018 2017 Foreign currency translation adjustments 1 $ 6.7 $ 15.7 $ 1.1 Other expense, net Gains on available-for-sale securities 0.0 0.0 (0.7 ) Other expense, net Losses on derivative instruments 2.3 2.2 2.1 Interest expense Amortization of defined benefit pension and postretirement plans items 6.7 6.5 13.7 Other expense, net Tax effect (1.9 ) (2.3 ) (2.1 ) Provision for income taxes Total amount reclassified from accumulated other comprehensive loss, net of tax $ 13.8 $ 22.1 $ 14.1 1 These foreign currency translation adjustments are primarily a result of the sales of businesses.

Incentive Compensation Plans Sc

Incentive Compensation Plans Schedule of Stock-based Compensation Expense (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Schedule of Stock-based Compensation Expense	The amounts of stock-based compensation expense as reflected in salaries and related expenses in our Consolidated Statements of Operations, and the related tax benefit, are listed below. Years ended December 31, 2019 2018 2017 Stock-settled awards $ 33.5 $ 24.7 $ 20.5 Cash-settled awards 0.8 0.6 1.0 Performance-based awards 46.7 57.5 61.5 Employee stock purchase plan 1.1 0.9 1.0 Other 1 0.6 0.9 0.5 Stock-based compensation expense $ 82.7 $ 84.6 $ 84.5 Tax benefit $ 20.0 $ 20.4 $ 30.4 1 Represents charges recorded for severance expense related to stock-based compensation awards.

Incentive Compensation Plans _2

Incentive Compensation Plans Schedule of Stock Options Activity (Tables)	12 Months Ended
	Dec. 31, 2019
Summary of Stock Options Assumptions [Abstract]
Share-based Payment Arrangement, Option, Activity [Table Text Block]	The following table summarizes our stock option activity during 2019 . Options Weighted- Average Exercise Price (per option) Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Stock options outstanding as of January 1, 2019 1.8 $ 10.66 Exercised (0.6 ) $ 7.38 Stock options outstanding as of December 31, 2019 1.2 $ 12.26 2.7 $ 12.9

Incentive Compensation Plans St

Incentive Compensation Plans Stock-based Compensation, Grants in Period Weighted Average (Tables)	12 Months Ended
	Dec. 31, 2019
Summary of Stock Options Assumptions [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value [Table Text Block]	Stock-based compensation awards expected to be settled in cash have been classified as liabilities in our Consolidated Balance Sheets as of December 31, 2019 and 2018 . Years ended December 31, 2019 2018 2017 Stock-Settled Awards: Awards granted 2.5 2.1 0.8 Weighted-average grant-date fair value (per award) $ 22.78 $ 23.60 $ 24.18 Total fair value of vested awards distributed $ 15.2 $ 24.2 $ 22.6 Cash-Settled Awards: Awards granted 0.0 0.1 0.0 Weighted-average grant-date fair value (per award) $ 22.83 $ 23.62 $ 23.33 Total fair value of vested awards distributed $ 0.9 $ 0.8 $ 0.9 Performance-Based Awards: Awards granted 2.1 2.9 4.8 Weighted-average grant-date fair value (per award) $ 20.16 $ 21.13 $ 20.06 Total fair value of vested awards distributed $ 64.9 $ 87.2 $ 112.4

Incentive Compensation Plans _3

Incentive Compensation Plans Schedule of Nonvested Stock Activity (Tables)	12 Months Ended
	Dec. 31, 2019
Summary of Stock Options Assumptions [Abstract]
Schedule of Nonvested Share Activity [Table Text Block]	A summary of the activity of our non-vested stock-settled awards, cash-settled awards and performance-based awards during 2019 is presented below (performance-based awards are shown at 100% of the shares originally granted). Stock-Settled Awards Cash-Settled Awards Performance-Based Awards Awards Weighted- Average Grant-Date Fair Value (per award) Awards Weighted- Average Grant-Date Fair Value (per award) Awards Weighted- Average Grant-Date Fair Value (per award) Non-vested as of January 1, 2019 3.1 $ 23.51 0.1 $ 23.47 7.0 $ 21.10 Granted 2.5 22.78 0.0 22.83 2.1 20.16 Vested (0.7 ) 22.78 0.0 23.53 (2.9 ) 19.93 Forfeited (0.2 ) 23.42 0.0 22.84 (0.6 ) 21.01 Non-vested as of December 31, 2019 4.7 $ 23.21 0.1 $ 23.20 5.6 $ 21.36 Total unrecognized compensation expense remaining $ 56.0 $ 1.2 $ 45.7 Weighted-average years expected to be recognized over 1.6 1.5 1.7

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value of Assets and Liabilities Measured on a Recurring Basis (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following tables present information about our financial instruments measured at fair value on a recurring basis as of December 31, 2019 and 2018 , and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. December 31, 2019 Balance Sheet Classification Level 1 Level 2 Level 3 Total Assets Cash equivalents $ 786.0 $ 0.0 $ 0.0 $ 786.0 Cash and cash equivalents Liabilities Contingent acquisition obligations 1 $ 0.0 $ 0.0 $ 114.1 $ 114.1 Accrued liabilities and Other non-current liabilities December 31, 2018 Balance Sheet Classification Level 1 Level 2 Level 3 Total Assets Cash equivalents $ 132.1 $ 0.0 $ 0.0 $ 132.1 Cash and cash equivalents Liabilities Contingent acquisition obligations 1 $ 0.0 $ 0.0 $ 148.4 $ 148.4 Accrued liabilities and Other non-current liabilities 1 Contingent acquisition obligations includes deferred acquisition payments and unconditional obligations to purchase additional noncontrolling equity shares of consolidated subsidiaries. Fair value measurement of the obligations is based upon actual and projected operating performance targets as specified in the related agreements. The decrease in this balance of $34.3 from December 31, 2018 to December 31, 2019 is primarily due to payments and a reclassification from an arrangement during the second quarter of 2019. The amounts payable within the next twelve months are classified in accrued liabilities; any amounts payable thereafter are classified in other non-current liabilities.

Fair Value Measurements Assets

Fair Value Measurements Assets and Liabilities Measured at Fair Value on a Nonrecurring (Tables)	12 Months Ended
	Dec. 31, 2019
Assets and Liabilities Measured at Fair Value on Recurring Basis [Abstract]
Fair Value Measurements, Nonrecurring [Table Text Block]	The following table presents information about our financial instruments that are not measured at fair value on a recurring basis as of December 31, 2019 , and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. December 31, 2019 Level 1 Level 2 Level 3 Total Total long-term debt $ 0.0 $ 3,520.0 $ 45.5 $ 3,565.5

Schedule of Defined Benefit Pla

Schedule of Defined Benefit Plans Disclosures (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Schedule of Defined Benefit Plans Disclosures	Pension and Postretirement Benefit Obligation The change in the benefit obligation, the change in plan assets, the funded status and amounts recognized for the Domestic Pension Plan, the significant foreign pension plans and the domestic postretirement benefit plan are listed below. Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan 2019 2018 2019 2018 2019 2018 Benefit Obligation Projected benefit obligation as of January 1 $ 115.4 $ 125.4 $ 496.0 $ 582.3 $ 27.7 $ 31.8 Service cost 0.0 0.0 4.8 5.4 0.0 0.0 Interest cost 4.8 4.5 12.4 13.1 1.2 1.1 Benefits paid (9.2 ) (9.5 ) (27.8 ) (27.4 ) (5.4 ) (5.9 ) Plan participant contributions 0.0 0.0 0.0 0.1 2.0 1.8 Actuarial losses (gains) 5.9 (5.0 ) 42.7 (47.6 ) 1.7 (1.1 ) Settlements and curtailments 0.0 0.0 (0.7 ) (5.8 ) 0.0 0.0 Foreign currency effect 0.0 0.0 13.8 (26.4 ) 0.0 0.0 Other 0.0 0.0 0.0 2.3 0.0 0.0 Projected benefit obligation as of December 31 $ 116.9 $ 115.4 $ 541.2 $ 496.0 $ 27.2 $ 27.7 Fair Value of Plan Assets Fair value of plan assets as of January 1 $ 89.8 $ 98.8 $ 363.9 $ 404.2 $ 0.0 $ 0.0 Actual return on plan assets 16.1 (8.1 ) 42.0 (8.0 ) 0.0 0.0 Employer contributions 2.4 8.6 18.0 19.1 3.4 4.1 Plan participant contributions 0.0 0.0 0.0 0.1 2.0 1.8 Benefits paid (9.2 ) (9.5 ) (27.8 ) (27.4 ) (5.4 ) (5.9 ) Settlements 0.0 0.0 0.0 (4.6 ) 0.0 0.0 Foreign currency effect 0.0 0.0 13.4 (21.1 ) 0.0 0.0 Other 0.0 0.0 0.0 1.6 0.0 0.0 Fair value of plan assets as of December 31 $ 99.1 $ 89.8 $ 409.5 $ 363.9 $ 0.0 $ 0.0 Funded status of the plans at December 31 $ (17.8 ) $ (25.6 ) $ (131.7 ) $ (132.1 ) $ (27.2 ) $ (27.7 ) Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan December 31, 2019 2018 2019 2018 2019 2018 Amounts recognized in Consolidated Balance Sheets Non-current asset $ 0.0 $ 0.0 $ 10.1 $ 8.6 $ 0.0 $ 0.0 Current liability 0.0 0.0 (5.8 ) (6.2 ) (2.7 ) (2.9 ) Non-current liability (17.8 ) (25.6 ) (136.0 ) (134.5 ) (24.5 ) (24.8 ) Net liability recognized $ (17.8 ) $ (25.6 ) $ (131.7 ) $ (132.1 ) $ (27.2 ) $ (27.7 ) Accumulated benefit obligation $ 116.9 $ 115.4 $ 538.6 $ 493.2 Amounts recognized in Accumulated Other Comprehensive Loss, net Net actuarial loss $ 54.2 $ 60.4 $ 183.2 $ 165.6 $ 4.7 $ 3.1 Prior service cost (credit) 0.0 0.0 1.1 1.2 (0.1 ) (0.3 ) Total amount recognized $ 54.2 $ 60.4 $ 184.3 $ 166.8 $ 4.6 $ 2.8 Actuarial losses of $5.9 for the Domestic Pension Plan are attributed to a decrease in the discount rate from 4.35% as of December 31, 2018 to 3.35% as of December 31, 2019 , offset by changes in the mortality assumption and demographic experience. Actuarial losses of $42.7 for the foreign pension plans are attributed to a decrease in the weighted-average discount rate from 2.61% as of December 31, 2018 to 1.84% as of December 31, 2019 offset by changes in demographic experience. Domestic Pension Plan Foreign Pension Plans December 31, 2019 2018 2019 2018 Pension plans with an accumulated benefit obligation and projected benefit obligation in excess of plan assets Aggregate projected benefit obligation $ 116.9 $ 115.4 $ 534.6 $ 491.2 Aggregate accumulated benefit obligation 116.9 115.4 533.5 489.9 Aggregate fair value of plan assets 99.1 89.8 392.7 350.5

Employee Benefits Schedule of N

Employee Benefits Schedule of Net Benefit Costs (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs [Table Text Block]	Net Periodic Cost The components of net periodic benefit cost and key assumptions are listed below. Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan Years ended December 31, 2019 2018 2017 2019 2018 2017 2019 2018 2017 Service cost $ 0.0 $ 0.0 $ 0.0 $ 4.8 $ 5.4 $ 4.9 $ 0.0 $ 0.0 $ 0.0 Interest cost 4.8 4.5 5.1 12.4 13.1 13.5 1.2 1.1 1.3 Expected return on plan assets (5.9 ) (6.6 ) (6.2 ) (17.4 ) (18.8 ) (17.7 ) 0.0 0.0 0.0 Settlement and curtailment (gains) losses 0.0 0.0 0.0 0.0 (1.0 ) 6.8 0.0 0.0 0.0 Amortization of: Prior service cost (credit) 0.0 0.0 0.0 0.1 0.1 0.1 (0.2 ) (0.2 ) (0.2 ) Net actuarial losses 1.9 1.6 1.5 4.8 5.9 5.5 0.1 0.1 0.0 Net periodic cost $ 0.8 $ (0.5 ) $ 0.4 $ 4.7 $ 4.7 $ 13.1 $ 1.1 $ 1.0 $ 1.1 Assumptions Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan Years ended December 31, 2019 2018 2017 2019 2018 2017 2019 2018 2017 Net periodic cost Discount rate 4.35 % 3.70 % 4.20 % 2.61 % 2.36 % 2.52 % 4.30 % 3.65 % 4.05 % Rate of compensation increase N/A N/A N/A 2.58 % 2.37 % 2.36 % N/A N/A N/A Expected return on plan assets 7.00 % 7.00 % 7.00 % 4.76 % 4.70 % 4.66 % N/A N/A N/A Interest crediting rates 5.10 % 5.10 % 5.10 % 1.44 % 1.31 % 1.29 % N/A N/A N/A Benefit obligation Discount rate 3.35 % 4.35 % 3.70 % 1.84 % 2.61 % 2.36 % 3.25 % 4.30 % 3.65 % Rate of compensation increase N/A N/A N/A 2.51 % 2.58 % 2.37 % N/A N/A N/A Interest crediting rates 5.10 % 5.10 % 5.10 % 1.37 % 1.44 % 1.31 % N/A N/A N/A Health care cost trend rate assumed for next year Initial rate (weighted-average) 7.00 % 6.25 % 6.50 % Year ultimate rate is reached 2028 2024 2024 Ultimate rate 5.00 % 5.00 % 5.00 %

Employee Benefits Fair Value of

Employee Benefits Fair Value of Pension Plan Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Fair Value of Pension Plan Assets [Table Text Block]	The following table presents the fair value of our domestic and foreign pension plan assets as of December 31, 2019 and 2018 , and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. See Note 13 for a description of the fair value hierarchy. December 31, 2019 December 31, 2018 Plan assets subject to fair value hierarchy Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Registered investment companies $ 18.0 $ 0.0 $ 0.0 $ 18.0 $ 13.0 $ 0.0 $ 0.0 $ 13.0 Limited partnerships 0.0 0.0 25.6 25.6 0.0 0.0 25.6 25.6 Fixed income securities 19.6 0.0 0.0 19.6 23.1 0.0 0.0 23.1 Insurance contracts 0.0 5.5 0.0 5.5 0.0 5.8 0.0 5.8 Other 27.8 0.0 0.0 27.8 20.0 0.0 0.0 20.0 Total plan assets, subject to leveling $ 65.4 $ 5.5 $ 25.6 $ 96.5 $ 56.1 $ 5.8 $ 25.6 $ 87.5 Plan assets measured at net asset value Other investments measured at net asset value 1 412.1 366.2 Total plan assets $ 508.6 $ 453.7 1 Certain investments that are measured at fair value using the net asset value per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy but are included to reconcile to the amounts presented in the fair value of plan assets table above.

Employee Benefits Schedule of E

Employee Benefits Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets [Table Text Block]	The following table presents additional information about our significant foreign pension plan assets for which we utilize Level 3 inputs to determine fair value. Years ended December 31, Plan assets subject to fair value hierarchy, Level 3 2019 2018 Balance at beginning of period $ 25.6 $ 29.5 Actual return on plan assets 0.0 (3.9 ) Balance at end of period $ 25.6 $ 25.6

Employee Benefits Schedule of A

Employee Benefits Schedule of Allocation of Plan Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Schedule of Allocation of Plan Assets [Table Text Block]	As of December 31, 2019 , the weighted-average target and actual asset allocations relating to our domestic and foreign pension plans' assets are listed below. December 31, Asset Class 2020 Target Allocation 2019 2018 Alternative investments 1 25 % 25 % 26 % Equity securities 25 % 25 % 22 % Fixed income securities 20 % 19 % 21 % Liability driven investments 2 14 % 14 % 16 % Real estate 9 % 9 % 6 % Other 7 % 8 % 9 % Total 100 % 100 % 100 % 1 Alternative investments have the flexibility to dynamically invest across a broad range of asset classes including bonds, equity, cash, property and commodities. 2 Liability driven investment strategies use government bonds as well as derivative instruments to hedge a portion of the impact of interest rates and inflation movements on the long-term liabilities.

Employee Benefits Schedule of_2

Employee Benefits Schedule of Estimated Future Benefit Payments (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Schedule of Expected Benefit Payments [Table Text Block]	The estimated future benefit payments expected to be paid are presented below. Years Domestic Pension Plan Foreign Pension Plans Domestic Postretirement Benefit Plan 2020 $ 14.6 $ 21.7 $ 2.7 2021 8.0 19.8 2.6 2022 8.1 21.0 2.4 2023 7.6 21.9 2.2 2024 7.5 22.7 2.1 2025 - 2029 34.6 116.7 8.8

Segment Information Schedule of

Segment Information Schedule of Segment Reporting Information, by Segment (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Summarized financial information concerning our reportable segments is shown in the following tables. Years ended December 31, 2019 2018 2017 Total Revenue: IAN $ 8,026.4 $ 7,556.1 $ 7,009.6 CMG 2,194.9 2,158.3 2,038.0 Total $ 10,221.3 $ 9,714.4 $ 9,047.6 Net revenue: IAN $ 7,348.2 $ 6,767.5 $ 6,266.7 CMG 1,276.9 1,264.1 1,206.8 Total $ 8,625.1 $ 8,031.6 $ 7,473.5 Segment EBITA: IAN $ 1,110.4 $ 1,042.1 $ 891.7 CMG 163.4 180.3 194.4 Corporate and other (101.8 ) (176.0 ) (126.6 ) Total $ 1,172.0 $ 1,046.4 $ 959.5 Amortization of acquired intangibles: IAN $ 81.6 $ 32.3 $ 16.6 CMG 4.4 5.3 4.5 Corporate and other 0.0 0.0 0.0 Total $ 86.0 $ 37.6 $ 21.1 Depreciation and amortization 1 : IAN $ 166.0 $ 136.8 $ 108.9 CMG 19.2 19.0 19.0 Corporate and other 7.3 9.5 8.1 Total $ 192.5 $ 165.3 $ 136.0 Capital expenditures: IAN $ 161.8 $ 143.9 $ 112.0 CMG 13.3 13.0 17.7 Corporate and other 23.4 20.2 26.2 Total $ 198.5 $ 177.1 $ 155.9 1 Excludes amortization of acquired intangibles. December 31, 2019 2018 Total assets: IAN $ 15,170.3 $ 13,867.9 CMG 1,710.4 1,516.7 Corporate and other 871.2 235.7 Total $ 17,751.9 $ 15,620.3 The following table presents the reconciliation of segment EBITA to Income before income taxes. Years ended December 31, 2019 2018 2017 IAN EBITA $ 1,110.4 $ 1,042.1 $ 891.7 CMG EBITA 163.4 180.3 194.4 Corporate and other EBITA (101.8 ) (176.0 ) (126.6 ) Less: consolidated amortization of acquired intangibles 86.0 37.6 21.1 Operating income 1,086.0 1,008.8 938.4 Total (expenses) and other income (207.7 ) (170.8 ) (97.6 ) Income before income taxes $ 878.3 $ 838.0 $ 840.8

Segment Information Schedule _2

Segment Information Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]	Long-lived assets, including operating lease right-of-use assets and excluding intangible assets, are presented by major geographic area in the following table. Long-Lived Assets December 31, 2019 2018 Domestic $ 2,080.4 $ 892.9 International: United Kingdom 167.6 57.9 Continental Europe 149.7 57.9 Asia Pacific 240.9 121.7 Latin America 74.8 43.6 Other 130.4 45.7 Total International 763.4 326.8 Total Consolidated $ 2,843.8 $ 1,219.7 Property and equipment are allocated based upon physical location. Other assets and investments are allocated based on the location of the related operations.

Commitments and Contingencies S

Commitments and Contingencies Schedule of Contingent Acquisition Obligations (Tables)	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table Text Block]	Contingent Acquisition Obligations The following table details the estimated future contingent acquisition obligations payable in cash as of December 31, 2019 . 2020 2021 2022 2023 2024 Thereafter Total Deferred acquisition payments $ 45.7 $ 30.4 $ 7.4 $ 4.4 $ 2.4 $ 0.0 $ 90.3 Redeemable noncontrolling interests and call options with affiliates 1 26.2 37.9 32.4 6.2 2.5 0.2 105.4 Total contingent acquisition payments $ 71.9 $ 68.3 $ 39.8 $ 10.6 $ 4.9 $ 0.2 $ 195.7 1 We have entered into certain acquisitions that contain both redeemable noncontrolling interests and call options with similar terms and conditions. The estimated amounts listed would be paid in the event of exercise at the earliest exercise date. We have certain redeemable noncontrolling interests that are exercisable at the discretion of the noncontrolling equity owners as of December 31, 2019 . These estimated payments of $21.5 are included within the total payments expected to be made in 2020 , and will continue to be carried forward into 2021 or beyond until exercised or expired. Redeemable noncontrolling interests are included in the table at current exercise price payable in cash, not at applicable redemption value, in accordance with the authoritative guidance for classification and measurement of redeemable securities. The majority of these payments are contingent upon achieving projected operating performance targets and satisfying other conditions specified in the related agreements and are subject to revision in accordance with the terms of the respective agreements. See Note 6 for further information relating to the payment structure of our acquisitions.

Results by Quarter (Unaudited_2

Results by Quarter (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Results by Quarter (Unaudited) Three Months Ended March 31, Three Months Ended June 30, Three Months Ended September 30, Three Months Ended December 31, 2019 2018 2019 2018 2019 2018 2019 2018 Revenue: Net revenue $ 2,004.8 $ 1,774.0 $ 2,125.9 $ 1,948.2 $ 2,061.4 $ 1,895.7 $ 2,433.0 $ 2,413.7 Billable expenses 356.4 395.1 394.3 443.6 376.7 401.8 468.8 442.3 Total Revenue 2,361.2 2,169.1 2,520.2 2,391.8 2,438.1 2,297.5 2,901.8 2,856.0 Operating Expenses: Salaries and related expenses 1,421.1 1,330.3 1,381.2 1,292.9 1,334.4 1,251.4 1,432.1 1,423.7 Office and other direct expenses 389.2 323.8 387.3 333.3 367.9 317.0 419.7 381.0 Billable expenses 356.4 395.1 394.3 443.6 376.7 401.8 468.8 442.3 Cost of services 2,166.7 2,049.2 2,162.8 2,069.8 2,079.0 1,970.2 2,320.6 2,247.0 Selling, general and administrative expenses 1 41.4 35.1 18.1 28.8 9.8 21.6 24.5 81.0 Depreciation and amortization 71.1 46.0 73.0 44.0 69.0 44.0 65.4 68.9 Restructuring Charges 2 31.8 0.0 2.1 0.0 0.0 0.0 0.0 0.0 Total operating expenses 2,311.0 2,130.3 2,256.0 2,142.6 2,157.8 2,035.8 2,410.5 2,396.9 Operating income 50.2 38.8 264.2 249.2 280.3 261.7 491.3 459.1 Other (expense) income, net 3 (6.9 ) (24.4 ) (3.8 ) (16.3 ) (7.4 ) (15.3 ) (24.8 ) (13.6 ) Total (expenses) and other income (48.9 ) (40.3 ) (47.7 ) (37.7 ) (47.6 ) (37.6 ) (63.5 ) (55.2 ) Provision for income taxes 4 10.5 12.7 43.6 63.6 64.6 60.7 86.1 62.2 Net (loss) income (9.5 ) (16.1 ) 172.8 147.8 168.4 163.5 342.2 342.5 Net (loss) income available to IPG common stockholders $ (8.0 ) $ (14.1 ) $ 169.5 $ 145.8 $ 165.6 $ 161.0 $ 328.9 $ 326.2 (Loss) earnings per share available to IPG common stockholders: Basic $ (0.02 ) $ (0.04 ) $ 0.44 $ 0.38 $ 0.43 $ 0.42 $ 0.85 $ 0.85 Diluted $ (0.02 ) $ (0.04 ) $ 0.43 $ 0.37 $ 0.42 $ 0.41 $ 0.84 $ 0.84 Dividends declared per common share $ 0.235 $ 0.210 $ 0.235 $ 0.210 $ 0.235 $ 0.210 $ 0.235 $ 0.210 1 The three months ended June 30, September 30 and December 31, 2018 included transaction costs of $1.4 , $11.0 , and $22.6 , respectively, related to the acquisition of Acxiom. See "Acquisitions" Note 6 for further information. 2 The three months ended March 31, 2019 and June 30, 2019 included restructuring charges of $31.8 and $2.1 , respectively. See "Restructuring Charges" Note 11 for further information. 3 The three months ended March 31, June 30, September 30 and December 31, 2019 included pre-tax net losses of $8.6 , $3.2 , $7.7 , and $23.9 , respectively, on sales of businesses. The three months ended March 31, June 30, September 30 and December 31, 2018 included pre-tax net losses of $24.4 , $19.8 , $5.8 , and $11.9 , respectively, on sales of businesses. 4 The three months ended June 30 and December 31, 2019 included a tax benefit of $13.9 related to the settlement of certain tax positions and $25.3 related to valuation allowance reversals, respectively. The three months ended December 31, 2018 included a tax benefit of $23.4

Restructuring Charges (Tables)

Restructuring Charges (Tables)	12 Months Ended
	Dec. 31, 2019
Restructuring Charges [Abstract]
Restructuring and Related Costs [Table Text Block]	In the first quarter of 2019, the Company implemented a cost initiative (the "2019 Plan") to better align our cost structure with our revenue primarily related to specific client losses occurring in 2018, the components of which are listed below. Years ended December 31, 2019 2018 2017 Severance and termination costs $ 22.0 $ 0.0 $ 0.0 Lease restructuring costs 11.9 0.0 (0.4 ) Total restructuring charges $ 33.9 $ 0.0 $ (0.4 )

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Lease, Cost [Table Text Block]	The following table presents information on our operating leases for the full year of 2019 . Twelve months ended Operating lease cost $ 325.2 Short-term lease cost 13.8 Sublease income (12.9 ) Total lease cost $ 326.1 Twelve months ended Cash paid for amounts included in the measurement of lease liabilities $ 334.1 Right-of-use assets obtained in exchange for lease liabilities $ 422.8 As of December 31, 2019 Weighted-average remaining lease term Eight years Weighted-average discount rate 4.26 %
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Our future payments of our operating leases as of December 31, 2019 are listed in the table below. Period Net Rent 2020 $ 333.5 2021 300.7 2022 267.5 2023 209.7 2024 183.5 Thereafter 716.1 Total future lease payments 2,011.0 Less: imputed interest 314.2 Present value of future lease payments 1,696.8 Less: current portion of operating leases 267.2 Non-current operating leases $ 1,429.6	Our future payments of our operating leases as of December 31, 2018 are listed in the table below. Period Rent Obligations Sublease Rental Income Net Rent 2019 $ 352.0 $ (7.7 ) $ 344.3 2020 324.3 (5.2 ) 319.1 2021 282.3 (2.2 ) 280.1 2022 242.5 (1.3 ) 241.2 2023 184.0 (0.6 ) 183.4 Thereafter 714.6 (0.5 ) 714.1 Total future lease payments $ 2,099.7 $ (17.5 ) $ 2,082.2

Summary of Significant Accounti

Summary of Significant Accounting Policies (Details) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)shares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)	Jan. 01, 2019USD ($)
Operating Lease, Right-of-Use Asset	$ 1,574.4	$ 0			$ 1,421.1
Operating Lease, Liability	1,696.8				$ 1,544.4
Revenue, remaining performance obligation, amount	$ 704
Retirement of treasury stock, amount		0	$ 0
ERP Systems, Useful Life	P10Y
Minimum Remaining Lease Term	1 year
Maximum Remaining Lease Term	20 years
Leasehold Improvements, Useful Life	the shorter of the useful life or the remaining lease term
Number of Reporting Units for Purposes of Annual Goodwill Impairment Test	12
Foreign Currency Transaction pre-tax Gain (Loss)	$ 5.3	$ (5.6)	$ (1.9)
Minimum
Furniture and Equipment, Useful Life	3 years
Buildings, Useful Life	10 years
Other Internal Use Software, Useful Life	P3Y
Identifiable Intangible Assets, Useful Life	7 years
Maximum
Furniture and Equipment, Useful Life	7 years
Buildings, Useful Life	35 years
Other Internal Use Software, Useful Life	P7Y
Identifiable Intangible Assets, Useful Life	15 years
Common Stock [Member]
Retirement of treasury stock, shares | shares		8.1	13.4
Retirement of treasury stock, amount		$ (0.8)	$ (1.3)
Treasury Stock [Member]
Retirement of treasury stock, amount		(176.1)	(304.4)
Additional Paid-in Capital [Member]
Retirement of treasury stock, amount		$ (175.3)	$ (303.1)

Revenue Income Statement (Detai

Revenue Income Statement (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenue	$ 2,433	$ 2,061.4	$ 2,125.9	$ 2,004.8	$ 2,413.7	$ 1,895.7	$ 1,948.2	$ 1,774	$ 8,625.1	$ 8,031.6	$ 7,473.5
Billable expenses	468.8	376.7	394.3	356.4	442.3	401.8	443.6	395.1	1,596.2	1,682.8	1,574.1
Total revenue	2,901.8	2,438.1	2,520.2	2,361.2	2,856	2,297.5	2,391.8	2,169.1	10,221.3	9,714.4	9,047.6
OPERATING EXPENSES:
Salaries and related expenses	1,432.1	1,334.4	1,381.2	1,421.1	1,423.7	1,251.4	1,292.9	1,330.3	5,568.8	5,298.3	4,990.7
Office and other direct expenses	419.7	367.9	387.3	389.2	381	317	333.3	323.8	1,564.1	1,355.1	1,269.2
Billable expense	468.8	376.7	394.3	356.4	442.3	401.8	443.6	395.1	1,596.2	1,682.8	1,574.1
Cost of services	2,320.6	2,079	2,162.8	2,166.7	2,247	1,970.2	2,069.8	2,049.2	8,729.1	8,336.2	7,834
Selling, General and Administrative Expense	24.5	9.8	18.1	41.4	81	21.6	28.8	35.1	93.8	166.5	118.5
Depreciation and amortization	65.4	69	73	71.1	68.9	44	44	46	278.5	202.9	157.1
Total operating expenses	2,410.5	2,157.8	2,256	2,311	2,396.9	2,035.8	2,142.6	2,130.3	9,135.3	8,705.6	8,109.2
Operating Income (Loss)	491.3	280.3	264.2	50.2	459.1	261.7	249.2	38.8	1,086	1,008.8	938.4
EXPENSES AND OTHER INCOME:
Interest Expense									(199.3)	(123)	(90.8)
Interest income									34.5	21.8	19.4
Other expense, net	(24.8)	(7.4)	(3.8)	(6.9)	(13.6)	(15.3)	(16.3)	(24.4)	(42.9)	(69.6)	(26.2)
Total (expenses) and other income	(63.5)	(47.6)	(47.7)	(48.9)	(55.2)	(37.6)	(37.7)	(40.3)	(207.7)	(170.8)	(97.6)
Income before income taxes									878.3	838	840.8
Provision for income taxes	86.1	64.6	43.6	10.5	62.2	60.7	63.6	12.7	204.8	199.2	271.3
Income of consolidated companies									673.5	638.8	569.5
Equity in net (loss) income of unconsolidated affiliates									0.4	(1.1)	0.9
NET INCOME	$ 342.2	$ 168.4	$ 172.8	$ (9.5)	$ 342.5	$ 163.5	$ 147.8	$ (16.1)	673.9	637.7	570.4
Net Income (Loss) Attributable to Parent									$ 656	$ 618.9	$ 554.4
Earnings per share, Basic	$ 0.85	$ 0.43	$ 0.44	$ (0.02)	$ 0.85	$ 0.42	$ 0.38	$ (0.04)	$ 1.70	$ 1.61	$ 1.42
Earnings per share, Diluted	$ 0.84	$ 0.42	$ 0.43	$ (0.02)	$ 0.84	$ 0.41	$ 0.37	$ (0.04)	$ 1.68	$ 1.59	$ 1.40
Weighted-average number of common shares outstanding, Basic									386.1	383.3	389.6
Weighted-average number of common shares outstanding, Diluted									391.2	389	397.3

Revenue Balance Sheet (Details)

Revenue Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents	$ 1,192.2	$ 673.4
Accounts receivable, net of allowance of $40.2 and $42.5, respectively	5,209.2	5,126.6
Accounts receivable, billable to clients	1,934.1	1,900.6
Assets held for sale	22.8	5.7
Other current assets	412.4	476.6
Assets, Current	8,770.7	8,182.9
Deferred income taxes	252.1	247
Property, Plant and Equipment, Net	778.1	790.9
Goodwill	4,894.4	4,875.9	$ 3,820.4
Other intangible assets	1,014.3	1,094.7
Other non-current assets	467.9	428.9
Assets	17,751.9	15,620.3
Accounts Payable, Current	7,205.4	6,698.1
Accrued Liabilities, Current	742.8	806.9
Contract liabilities	585.6	533.9
Short-term borrowings	52.4	73.7
Current portion of long-term debt	502	0.1
Liabilities held for sale	65	11.2
Liabilities, Current	9,420.4	8,123.9
Long-term debt	2,771.9	3,660.2
Deferred compensation	425	422.7
Other non-current liabilities	714.7	812.8
Liabilities	14,761.6	13,019.6
Redeemable noncontrolling interests	164.7	167.9	252.1	$ 252.8
STOCKHOLDERS' EQUITY:
Common stock, $0.10 par value, shares authorized: 800.0 shares issued: 2019 - 387.0; 2018 - 383.6 shares outstanding: 2019 - 387.0; 2018 - 383.6	38.7	38.3
Additional Paid in Capital	977.3	895.9
Retained Earnings (Accumulated Deficit)	2,689.9	2,400.1
Accumulated other comprehensive loss, net of tax	(930)	(941.1)	(827.8)
Stockholders' Equity Attributable to Parent	2,775.9	2,393.2
Stockholders' Equity Attributable to Noncontrolling Interest	49.7	39.6
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,825.6	2,432.8	$ 2,246.3	$ 2,090.4
Liabilities and Equity	$ 17,751.9	$ 15,620.3

Revenue Statement of Cash Flows

Revenue Statement of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
NET INCOME	$ 342.2	$ 168.4	$ 172.8	$ (9.5)	$ 342.5	$ 163.5	$ 147.8	$ (16.1)	$ 673.9	$ 637.7	$ 570.4
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization									278.5	202.9	157.1
Provision for uncollectible receivables									10.1	6.5	9.5
Amortization of restricted stock and other non-cash compensation									80.2	82.2	82
Net amortization of bond discounts and deferred financing costs									9.3	6.5	5.8
Deferred income tax provision									9.7	14.1	(9.5)
Net losses on sales of businesses	(23.9)	$ (7.7)	$ (3.2)	$ (8.6)	(11.9)	$ (5.8)	$ (19.8)	$ (24.4)	43.4	61.9	24.1
Other									9.9	1.2	12.7
Net Cash Provided by (Used in) Investing Activities [Abstract]
Accounts receivable									(111.2)	(603.8)	37.6
Accounts receivable, billable to clients									(38.7)	(209.5)	(165.5)
Other current assets									(27.2)	(67.2)	50.1
Accounts payable									546	428.7	336.4
Accrued liabilities									27.4	(24.2)	(241.3)
Contract liabilities									46.5	44.9	(12)
Other non-current assets and liabilities									(29.3)	(16.8)	24.4
Net cash provided by operating activities									1,529.2	565.1	881.8
Net cash used in investing activities									(161.7)	(2,491.5)	(196.2)
Net cash (used in) provided by financing activities									(843)	1,853.2	(1,004.9)
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash									(6)	(47.3)	16.8
Net increase (decrease) in cash, cash equivalents and restricted cash									518.5	(120.5)	(302.5)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 1,195.7				$ 677.2				$ 1,195.7	$ 677.2	$ 797.7	$ 1,100.2

Revenue Major Geographical Area

Revenue Major Geographical Area (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total revenue	$ 2,901.8	$ 2,438.1	$ 2,520.2	$ 2,361.2	$ 2,856	$ 2,297.5	$ 2,391.8	$ 2,169.1	$ 10,221.3	$ 9,714.4	$ 9,047.6
Net revenue	$ 2,433	$ 2,061.4	$ 2,125.9	$ 2,004.8	$ 2,413.7	$ 1,895.7	$ 1,948.2	$ 1,774	8,625.1	8,031.6	7,473.5
United States
Total revenue									6,368.7	5,851	5,417.3
Net revenue									5,386.1	4,825	4,458.8
Total International
Total revenue									3,852.6	3,863.4	3,630.3
Net revenue									3,239	3,206.6	3,014.7
United Kingdom
Total revenue									871.8	881.4	775.7
Net revenue									727	711.7	613.1
Continental Europe
Total revenue									842.9	840.2	780.6
Net revenue									742.4	737.5	687.8
Asia Pacific
Total revenue									1,102.3	1,170.8	1,106.4
Net revenue									858.3	896.8	866.9
Latin America
Total revenue									431.6	389	386.6
Net revenue									389.9	350.1	350.8
Other
Total revenue									604	582	581
Net revenue									521.4	510.5	496.1
CMG
Total revenue									2,194.9	2,158.3	2,038
Net revenue									1,276.9	1,264.1	1,206.8
CMG | United States
Total revenue									1,456.2	1,404	1,355
Net revenue									828.6	824.6	798.2
CMG | Total International
Total revenue									738.7	754.3	683
Net revenue									448.3	439.5	408.6
IAN
Total revenue									8,026.4	7,556.1	7,009.6
Net revenue									7,348.2	6,767.5	6,266.7
IAN | United States
Total revenue									4,912.5	4,447	4,062.3
Net revenue									4,557.5	4,000.4	3,660.6
IAN | Total International
Total revenue									3,113.9	3,109.1	2,947.3
Net revenue									$ 2,790.7	$ 2,767.1	$ 2,606.1

Revenue Contract Balances (Deta

Revenue Contract Balances (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts receivable, net of allowance of $40.2 and $42.5, respectively	$ 5,209.2	$ 5,126.6
Accounts receivable, billable to clients	1,934.1	1,900.6
Contract with Customer, Asset, after Allowance for Credit Loss	63	67.9
Contract liabilities	585.6	$ 533.9
Revenue, remaining performance obligation, amount	$ 704

Debt and Credit Agreements Long

Debt and Credit Agreements Long-Term Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term debt, gross	$ 3,273.9	$ 3,660.3
Long-term debt, current maturities	502	0.1
Long-term debt, excluding current maturities	2,771.9	3,660.2
Deb instrument, unamortized debt issuance costs	21.6	26
Long-term debt, fair value	3,565.5
3.50% Notes Due 2020 (less unamortized discount and issuance costs of $0.4 and $1.1, respectively)
Debt Instrument [Line Items]
Senior Notes	500
Long-term debt, gross	498.5	496.6
Debt instrument, unamortized discount	0.4
Deb instrument, unamortized debt issuance costs	1.1
Long-term debt, fair value	$ 505.4	499.9
Debt instrument, maturity date	Oct. 1, 2020
Interest rate, stated percentage	3.50%
Debt instrument, interest rate, effective percentage	3.89%
3.75% Notes Due 2021 (less unamortized discount and issuance costs of $0.2 and $1.9, respectively)
Debt Instrument [Line Items]
Senior Notes	$ 500
Long-term debt, gross	497.9	496.8
Debt instrument, unamortized discount	0.2
Deb instrument, unamortized debt issuance costs	1.9
Long-term debt, fair value	$ 513.5	503.2
Debt instrument, maturity date	Oct. 1, 2021
Interest rate, stated percentage	3.75%
Debt instrument, interest rate, effective percentage	3.98%
4.00% Notes Due 2022 (less unamortized discount and issuance costs of $0.7 and $0.6, respectively)
Debt Instrument [Line Items]
Senior Notes	$ 250
Long-term debt, gross	248.7	248.2
Debt instrument, unamortized discount	0.7
Deb instrument, unamortized debt issuance costs	0.6
Long-term debt, fair value	$ 258.8	250.3
Debt instrument, maturity date	Mar. 15, 2022
Interest rate, stated percentage	4.00%
Debt instrument, interest rate, effective percentage	4.13%
3.75% Notes Due 2023 (less unamortized discount and issuance costs of $0.5 and $1.3, respectively)
Debt Instrument [Line Items]
Senior Notes	$ 500
Long-term debt, gross	498.2	497.7
Debt instrument, unamortized discount	0.5
Deb instrument, unamortized debt issuance costs	1.3
Long-term debt, fair value	$ 522.8	491.4
Debt instrument, maturity date	Feb. 15, 2023
Interest rate, stated percentage	3.75%
Debt instrument, interest rate, effective percentage	4.32%
4.20% Notes Due 2024 (less unamortized discount and issuance costs of $0.4 and $1.8, respectively)
Debt Instrument [Line Items]
Senior Notes	$ 500
Long-term debt, gross	497.8	497.3
Debt instrument, unamortized discount	0.4
Deb instrument, unamortized debt issuance costs	1.8
Long-term debt, fair value	$ 538.1	492.6
Debt instrument, maturity date	Apr. 15, 2024
Interest rate, stated percentage	4.20%
Debt instrument, interest rate, effective percentage	4.24%
4.65% Notes Due 2028 (less unamortized discount and issuance costs of $1.5 and $3.9, respectively)
Debt Instrument [Line Items]
Senior Notes	$ 500
Long-term debt, gross	494.6	494
Debt instrument, unamortized discount	1.5
Deb instrument, unamortized debt issuance costs	3.9
Long-term debt, fair value	$ 564.3	494.1
Debt instrument, maturity date	Oct. 1, 2028
Interest rate, stated percentage	4.65%
Debt instrument, interest rate, effective percentage	4.78%
5.40% Notes Due 2048 (less unamortized discount and issuance costs of $2.7 and $5.4, respectively)
Debt Instrument [Line Items]
Senior Notes	$ 500
Long-term debt, gross	491.9	491.7
Debt instrument, unamortized discount	2.7
Deb instrument, unamortized debt issuance costs	5.4
Long-term debt, fair value	$ 617.1	474.1
Debt instrument, maturity date	Oct. 1, 2048
Interest rate, stated percentage	5.40%
Debt instrument, interest rate, effective percentage	5.48%
Term Loan Due 2021 (LIBOR plus 1.25%)
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	400
Loans Payable, Fair Value Disclosure	0	400
Other notes payable and capitalized leases
Debt Instrument [Line Items]
Long-term debt, gross	46.3	38
Long-term debt, fair value	$ 45.5	$ 38

Debt and Credit Agreements Debt

Debt and Credit Agreements Debt Transactions (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019
Schedule of New Debt Issuance [Line Items]
Repayments of Debt	$ 100	$ 200	$ 100
3.50% Notes Due 2020
Schedule of New Debt Issuance [Line Items]
Debt Instrument, Face Amount	500
3.75% Notes Due 2021
Schedule of New Debt Issuance [Line Items]
Debt Instrument, Face Amount	500
4.65% Notes Due 2028
Schedule of New Debt Issuance [Line Items]
Debt Instrument, Face Amount	500
5.40% Notes Due 2048
Schedule of New Debt Issuance [Line Items]
Debt Instrument, Face Amount	$ 500

Debt and Credit Agreements Annu

Debt and Credit Agreements Annual Maturities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Long-term debt, maturities, repayments of principal in next twelve months	$ 502
Long-term debt, maturities, repayments of principal in year two	501.4
Long-term debt, maturities,repayments of principal in year three	248.9
Long-term debt, maturities, repayments of principal in year four	498.3
Long-term debt, maturities, repayments of principal in year five	497.8
Long-term debt, maturities, repayments of principal after year five	1,025.5
Total long-term debt	$ 3,273.9	$ 3,660.3

Debt and Credit Agreements Cred

Debt and Credit Agreements Credit Agreements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Cash debt pooling arrangements, amount netted	$ 2,274.9	$ 2,065.8
Margin for base rate advances	0.125%
Margin for Eurocurrency rate advances	1.125%
Annual rate for fronting fees accrued on letters of credit	0.25%
Annual facility fee	0.125%
Leverage ratio maximum	3.75x
Leverage Ratio Acquisition Price Threshold	$ 200
Committed credit facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	1,500
Line of credit facility, available capacity increase amount	250
Limits on letters of credit	50
Line of credit facility, amount outstanding	0
Letters of credit, amount outstanding	8.4	8.5
Line of credit facility, remaining borrowing capacity	1,491.6	1,491.5
Uncommitted credit facility
Line of Credit Facility [Line Items]
Line of credit facility, amount outstanding	52.4	73.7
Line of Credit Facility, Average Outstanding Amount	88	96.4
Line of credit facility, current borrowing capacity	$ 1,056	$ 1,173.1
Line of credit facility, weighted average interest rate, over time	5.20%	4.50%

Debt and Credit Agreements Comm

Debt and Credit Agreements Commercial Paper (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Commercial paper, current borrowing capacity	$ 1,500
Debt Instrument, Term	397 days
Commercial paper, amount outstanding	$ 0
Commercial paper, average outstanding amount	$ 312.9	$ 648.7
Commercial paper, weighted average interest rate, over time	2.50%	2.40%
Commercial paper, weighted-average maturity days outstanding, over time		22 days

Debt and Credit Agreements Cash

Debt and Credit Agreements Cash Pooling (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Cash debt pooling arrangements, amount netted	$ 2,274.9	$ 2,065.8

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net Income (Loss) Attributable to Parent									$ 656	$ 618.9	$ 554.4
Weighted-average number of common shares outstanding, Basic									386.1	383.3	389.6
Restricted stock, stock options and other equity awards									5.1	5.7	7.7
Weighted-average number of common shares outstanding, Diluted									391.2	389	397.3
Basic	$ 0.85	$ 0.43	$ 0.44	$ (0.02)	$ 0.85	$ 0.42	$ 0.38	$ (0.04)	$ 1.70	$ 1.61	$ 1.42
Diluted	$ 0.84	$ 0.42	$ 0.43	$ (0.02)	$ 0.84	$ 0.41	$ 0.37	$ (0.04)	$ 1.68	$ 1.59	$ 1.40

Acquisitions Narrative (Details

Acquisitions Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Goodwill and intangible assets related to acquisitions	$ 7.6	$ 2,131	$ 62
Number of businesses acquired	1	5	10
IAN
Number of businesses acquired		2	8
CMG
Number of businesses acquired		3	2

Acquisitions Cash Paid for Acqu

Acquisitions Cash Paid for Acquisitions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Paid for Acquisitions [Abstract]
Cost of investment: current-year acquisitions 1	$ 0.6	$ 2,323.4	$ 36.8
Cost of investment: prior-year acquisitions	15.8	33.9	54.6
Less: net cash acquired	0	(13.8)	(7.1)
Total cost of investment	16.4	2,343.5	84.3
Operating payments	9.3	19.4	47.1
Total cash paid for acquisitions	25.7	2,362.9	131.4
Acquisitions, net of cash acquired	0.6	2,309.8	30.6
Payments for previous acquisition, financing cash flows	$ 15.8	$ 33.7	$ 53.7

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interests (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Redeemable Noncontrolling Interests
Balance at beginning of period	$ 167.9	$ 252.1	$ 252.8
Change in related noncontrolling interest balance	(2.8)	(10.7)	(2.8)
Changes in redemption value of redeemable noncontrolling interests:
Additions	24.3	0	7.7
Redemptions and other	(24.9)	(33.7)	(18.5)
Redemption value adjustments	0.2	(39.8)	12.9
Balance at end of period	$ 164.7	$ 167.9	$ 252.1

Acquisitions Acxiom Acquisition

Acquisitions Acxiom Acquisition (Details) - Business Acquisition, Acquiree [Domain] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Oct. 01, 2018
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue	$ 10,230.4	$ 9,736.1
Finite-Lived Intangible Assets, Gross			$ 995
Cash and Cash Equivalents, at Carrying Value			13.3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets			2,327.9
Loans Payable	500
Debt Issuance Face Amount	2,000
Accounts receivable, net of allowance			112.9
Accounts receivable, billable to clients			8.3
Other current assets			28.2
Property, Plant and Equipment, Net			159.7
Deferred Income Taxes and Other Tax Liabilities, Noncurrent			(0.6)
Goodwill			1,110.8
Intangible Assets, Net (Excluding Goodwill)			995
Other non-current assets			8.3
Accounts Payable			(37.1)
Accrued Liabilities			(46.9)
Contract liabilities			(23.2)
Other non-current liabilities			(0.8)
Net revenue	181.7
Net Income (Loss) Attributable to Parent	20.4
Selling, General and Administrative Expense	35
Interest Expense	3.7
Interest Income	0.4
Other expense, net	10.3
Business Acquisition, Pro Forma Information, Description		27.6
Business Acquisition, Pro Forma Net Income (Loss)	$ 642.2	$ 519.2
Customer Lists [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross			600
Finite-Lived Intangible Asset, Useful Life	15 years
know-how technology [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross			235
Finite-Lived Intangible Asset, Useful Life	9 years
Trade Names [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross			$ 160

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts - Allowance for Uncollectible Accounts Receivable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 42.5	$ 42.7	$ 55.7
Charges to costs and expenses	10.1	6.5	9.5
Acquisitions/(dispositions)	(0.3)	2.2	(1)
Uncollectible accounts written off	(11.9)	(7.1)	(25.5)
Foreign currency translation adjustment	(0.2)	(1.8)	4
Balance at end of period	$ 40.2	$ 42.5	$ 42.7

Supplementary Data Property a_2

Supplementary Data Property and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property and Equipment [Abstract]
Depreciation	$ 192.5	$ 165.3	$ 136
Property, Plant and Equipment [Line Items]
Furniture and equipment	694.3	681.7
Leasehold improvements	634.9	629
Internal-use computer software	422	368.5
Land and buildings	143.3	146.6
Total property and equipment, gross	1,894.5	1,825.8
Less: accumulated depreciation and amortization	(1,116.4)	(1,034.9)
Total property and equipment, net	$ 778.1	$ 790.9

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accrued Liabilities [Abstract]
Salaries, benefits and related expenses	$ 494.1	$ 494.9
Office and related expenses	26.9	52.2
Acquisition obligations	45.7	65.7
Interest	38.8	43.6
Restructuring Reserve	1.6	0
Other	135.7	150.5
Total accrued liabilities	$ 742.8	$ 806.9

Other Expense, Net (Details)

Other Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Nonoperating Income (Expense) [Abstract]
Net losses on sales of businesses	$ 23.9	$ 7.7	$ 3.2	$ 8.6	$ 11.9	$ 5.8	$ 19.8	$ 24.4	$ (43.4)	$ (61.9)	$ (24.1)
Other									0.5	(7.7)	(2.1)
Total other expense, net	$ (24.8)	$ (7.4)	$ (3.8)	$ (6.9)	$ (13.6)	$ (15.3)	$ (16.3)	$ (24.4)	$ (42.9)	$ (69.6)	$ (26.2)

Share Repurchase Program (Detai

Share Repurchase Program (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Aggregate cost, including fees	$ 117.1	$ 300.1
2017 Share Repurchase Program
Stock repurchase program, remaining authorized repurchase amount			$ 338.4

Supplemental Cash Flow Informat

Supplemental Cash Flow Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
Interest Paid, Excluding Capitalized Interest, Operating Activities		$ 192.7	$ 88.7	$ 82.3
Cash paid for income taxes, net of refunds	[1]	150.2	207.9	228.4
Tax refunds		$ 92.6	$ 24.3	$ 31.9
[1]	Refunds of $92.6 , $24.3 and $31.9 were received for the years ended December 31, 2019 , 2018 and 2017 , respectively.

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill
Goodwill	$ 4,894.4	$ 4,875.9	$ 3,820.4
Current year acquisitions	2.8	1,132
Foreign currency and other	15.7	(76.5)
IAN
Goodwill
Goodwill	4,225.8	4,209.3	3,161.8
Current year acquisitions	2.1	1,112
Foreign currency and other	14.4	(64.5)
CMG
Goodwill
Goodwill	668.6	666.6	$ 658.6
Current year acquisitions	0.7	20
Foreign currency and other	$ 1.3	$ (12)

Other Intangible Assets (Detail

Other Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Future amortization expense 2018	$ 88.4
Future amortization expense 2019	86.9
Future amortization expense 2020	82.9
Future amortization expense 2021	78.6
Future amortization expense 2022	76.8
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	86	$ 37.6	$ 21.1
Acquired finite-lived intangible assets related to acquisitions	5	999
Gross Amount	1,336.9	1,332.7
Accumulated Amortization	(322.6)	(238)
Net Amount	1,014.3	1,094.7
Customer lists
Finite-Lived Intangible Assets [Line Items]
Gross Amount	861.4	857.2
Accumulated Amortization	(244.6)	(190.9)
Net Amount	616.8	666.3
know-how technology
Finite-Lived Intangible Assets [Line Items]
Gross Amount	235	235
Accumulated Amortization	(32.9)	(6.5)
Net Amount	202.1	228.5
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Amount	226.2	226.2
Accumulated Amortization	(41.3)	(36.8)
Net Amount	184.9	189.4
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Amount	14.3	14.3
Accumulated Amortization	(3.8)	(3.8)
Net Amount	$ 10.5	$ 10.5
Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years

Components of Income Before Inc

Components of Income Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income before income taxes, Domestic	$ 557.4	$ 474	$ 514.8
Income before income taxes, Foreign	320.9	364	326
Income before income taxes	$ 878.3	$ 838	$ 840.8

Provision for Income Taxes (Det

Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
U.S. federal income taxes (including foreign withholding taxes):
Current federal income taxes									$ 92.2	$ 38.1	$ 154.1
Deferred federal income taxes									9.5	29.9	(37.6)
Total federal income taxes									101.7	68	116.5
State and local income taxes:
Current state and local income taxes									10.7	25.1	18.8
Deferred state and local income taxes									8.7	3.4	19.7
Total state and local income taxes									19.4	28.5	38.5
Foreign income taxes:
Current foreign income taxes									92.2	121.9	107.9
Deferred foreign income taxes									(8.5)	(19.2)	8.4
Total foreign income taxes									83.7	102.7	116.3
Provision for income taxes	$ 86.1	$ 64.6	$ 43.6	$ 10.5	$ 62.2	$ 60.7	$ 63.6	$ 12.7	$ 204.8	$ 199.2	$ 271.3

Reconciliation of Effective Inc

Reconciliation of Effective Income Tax Rate (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. federal statutory income tax rate										21.00%	21.00%	35.00%
Income tax provision at U.S. federal statutory rate										$ 184.5	$ 176	$ 294.3
State and local income taxes, net of federal income tax benefit										14	23.8	23.5
Impact of foreign operations, including withholding taxes										34.2	50.7	(6.7)
U.S. tax incentives										(21.4)	(17.5)	(1.3)
Change in net valuation allowance	[1]									(26.3)	(16.9)	1.4
Divestitures										9.6	11.7	1.1
U.S. federal tax credits										0.4	(48.1)	(0.4)
Stock compensation										(3.3)	(6.8)	(15.3)
Change in unrecognized tax benefits										14.1	8.4	7
Net impact of the Tax Act										0	13.4	(36)
Other										(1)	4.5	3.7
Provision for income taxes		$ 86.1	$ 64.6	$ 43.6	$ 10.5	$ 62.2	$ 60.7	$ 63.6	$ 12.7	$ 204.8	$ 199.2	$ 271.3
Effective income tax rate on operations										23.30%	23.80%	32.30%
[1]	Reflects changes in valuation allowances that impacted the effective income tax rate for each year presented.

Income Taxes Primary Impact on

Income Taxes Primary Impact on Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, Percent			23.30%	23.80%	32.30%
Previously unrecognized tax benefits		$ 13.9
Reversal of valuation allowance	$ 25.3

Components of Deferred Tax Asse

Components of Deferred Tax Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets, Net [Abstract]
Postretirement/post-employment benefits	$ 16.7	$ 17.9
Deferred compensation	99.5	99.8
Pension costs	23.7	22.2
Basis differences in fixed assets	(75.3)	(71.7)
Rent	0	27.3
Interest	45.5	48.8
Accruals and reserves	19.4	21
Allowance for doubtful accounts	6.5	7.4
Basis differences in intangible assets	(321)	(302.7)
Deferred Tax Assets, Investments	0.3	1.2
Deferred Tax Liabilities, ROU	335.2	0
Deferred Tax Liabilities, Leasing Arrangements	361.4	0
Tax loss/tax credit carry forwards	297.1	345.6
Prepaid expenses	(6.7)	(6.3)
Deferred revenue	(21.7)	(26.8)
Unremitted foreign earnings	(1.3)	(9.5)
Other	44.5	38.2
Net deferred tax assets	153.4	212.4
Valuation allowance	(164.2)	(211)	$ (243)	$ (255.6)
Total deferred tax assets, net	$ (10.8)	$ 1.4

Income Taxes Change in Valuatio

Income Taxes Change in Valuation Allowances (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 01, 2018
Summary of Valuation Allowances
Net impact of the Tax Act		$ 0	$ 13.4	$ (36)
Beginning balance		211	243	255.6
Reversed to costs and expenses		(24.9)	(28)	(4.6)
(Reversed) charged to gross tax assets and other accounts 1	[1]	(19.8)	5.1	(27.3)
Foreign currency translation		(2.1)	(9.1)	19.3
Ending balance		164.2	211	$ 243
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Operating Loss Carryforwards			1,044.1
Undistributed Earnings of Foreign Subsidiaries		$ 1,199.7	1,079.1		$ 435
Other Tax Expense (Benefit)			10.8
Foreign Tax Authority
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration			939
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration			105.1
State and Local Jurisdiction
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration			$ 25.6
[1]	Primarily represents changes to the valuation allowance related to the change of a corresponding deferred tax asset.

Unrecognized Tax Benefits (Deta

Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued [Abstract]
Balance at beginning of period	$ 335.4	$ 271.9	$ 246.7
Increases as a result of tax positions taken during a prior year	22.7	65.9	6.3
Decreases as a result of tax positions taken during a prior year	(25.8)	(10.8)	(8.1)
Settlements with taxing authorities	(8.1)	(6.5)	(0.8)
Lapse of statutes of limitation	(0.6)	(1.7)	(3.3)
Increases as a result of tax positions taken during the current year	21.7	16.6	31.1
Balance at end of period	345.3	335.4	$ 271.9
Income Tax Contingency [Line Items]
Unrecognized tax benefits that would impact effective tax rate	296.4
Income tax penalties and interest accrued	39.6	42.4
Income tax penalties and interest expense	(2.8)	$ 14.5
Minimum [Member]
Income Tax Contingency [Line Items]
Anticipated decrease in unrecognized tax benefits	10
Maximum [Member]
Income Tax Contingency [Line Items]
Anticipated decrease in unrecognized tax benefits	$ 20

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Loss, Net of Tax Changes in AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Available-for-sale securities, before reclassifications	$ 0	$ 0	$ 0
Total other comprehensive income, before reclassifications	(2.7)	(135.4)
Total reclassification from AOCI	13.8	22.1	14.1
Accumulated other comprehensive loss, net of tax	(930)	(941.1)	(827.8)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation adjustment, before reclassifications	12	(146.8)
Foreign currency translation adjustment, amount reclassified from AOCI, net of tax	6.7	15.7
Foreign currency translation adjustment, net of tax	(697.7)	(716.4)	(585.3)
Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative instruments, before reclassifications	0	0
Derivative instruments, amount reclassified from AOCI, net of tax	1.8	1.5
Derivative Instruments, net of tax	(3.5)	(5.3)	(6.8)
Defined Benefit and Postretirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Defined Benefit and Postretirement Plans, before reclassifications	(14.7)	11.4
Defined benefit and Postretirement Plans, amount reclassified from AOCI, net of tax	5.3	4.9
Pension and Other Postretirement Benefit Plans, net of tax	$ (228.8)	$ (219.4)	$ (235.7)

Accumulated Other Comprehensi_5

Accumulated Other Comprehensive Loss, Net of Tax Reclassifications from AOCI, net of tax (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total income tax effect	$ (1.9)	$ (2.3)	$ (2.1)
Total reclassified from AOCI, net of tax	13.8	22.1	14.1
Foreign Currency Translation Adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, before tax	6.7	15.7	1.1
Available-for-sale Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, before tax	0	0	(0.7)
Derivative Instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, before tax	2.3	2.2	2.1
Defined Benefit and Postretirement Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, before tax	$ 6.7	$ 6.5	$ 13.7

Plan Information (Details)

Plan Information (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deferred Compensation Liability, Current and Noncurrent	$ 197.5	$ 196.2
Incentive compensation plan initiation year	2019
2019 PIP target performance cash award percentage range	range from 0% to 300% of the target amount
2019 PIP target award percentage range - Executives	0% to 200%
Number of shares initially available for grant	27
Maximum shares participants are eligible to receive	2
Maximum cash award per employee	$ 10
Vesting period in which the fair value of shares on grant date is amortized over, years	3 years

Stock Based Compensation Expens

Stock Based Compensation Expense (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-based Payment Award
Stock-based compensation expense		$ 82.7	$ 84.6	$ 84.5
Tax benefit		20	20.4	30.4
Stock-settled awards
Stock-based Payment Award
Stock-based compensation expense		33.5	24.7	20.5
Cash-settled awards
Stock-based Payment Award
Stock-based compensation expense		0.8	0.6	1
Performance-based awards
Stock-based Payment Award
Stock-based compensation expense		46.7	57.5	61.5
Employee stock purchase plan
Stock-based Payment Award
Stock-based compensation expense		1.1	0.9	1
Other
Stock-based Payment Award
Stock-based compensation expense	[1]	$ 0.6	$ 0.9	$ 0.5
[1]	Represents charges recorded for severance expense related to stock-based compensation awards.

Incentive Compensation Plans _4

Incentive Compensation Plans Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-based Payment Award
Intrinsic value of stock options exercised	$ 9.1	$ 27.9	$ 15.1
Proceeds from stock options exercised including taxes withheld	8.3	29	20
Tax withheld on stock options received	$ 4	$ 13.3	$ 6.8
Employee Stock Option
Stock-based Payment Award
Stock options outstanding as of January 1, 2018	1.8
Stock options outstanding as of Jan 1, 2018, Weighted-average exercise price	$ 10.66
Exercised	(0.6)	(1.9)	(1.1)
Exercised, weighted-average exercise price	$ 7.38
Stock options outstanding as of December 31, 2018	1.2	1.8
Stock options outstanding as of Dec 31, 2018, Weighted-average exercise price	$ 12.26	$ 10.66
Options outstanding, weighted average remaining contractual term	2 years 8 months 12 days
Stock options outstanding, aggregate intrinsic value	$ 12.9

Share-based Compensation Awards

Share-based Compensation Awards (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-settled awards
Stock-based Payment Award
Awards granted	2.5	2.1	0.8
Weighted-average grant-date fair value (per award)	$ 22.78	$ 23.60	$ 24.18
Total fair value of vested awards distributed	$ 15.2	$ 24.2	$ 22.6
Accrued dividends on non-vested stock-settled awards	4.2	2.4
Dividends paid for stock-settled awards	$ 1.2	$ 1.5
Cash-settled awards
Stock-based Payment Award
Awards granted	0	0.1	0
Weighted-average grant-date fair value (per award)	$ 22.83	$ 23.62	$ 23.33
Total fair value of vested awards distributed	$ 0.9	$ 0.8	$ 0.9
Performance-based awards
Stock-based Payment Award
Awards granted	2.1	2.9	4.8
Weighted-average grant-date fair value (per award)	$ 20.16	$ 21.13	$ 20.06
Total fair value of vested awards distributed	$ 64.9	$ 87.2	$ 112.4

Non-vested Award Activity (Deta

Non-vested Award Activity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-settled awards
Stock-based Payment Award
Non-vested as of January 1, 2018	3.1
Nonvested as of January 1, 2018, weighted-average grant date fair value	$ 23.51
Granted	2.5
Granted, Weighted-average grant-date fair value	$ 22.78	$ 23.60	$ 24.18
Vested	(0.7)
Vested, Weighted-average grant date fair value	$ 22.78
Forfeited	(0.2)
Forfeited, Weighted-average grant date fair value	$ 23.42
Non-vested as of December 31, 2018	4.7	3.1
Nonvested as of December 31, 2018, weighted-average grant date fair value	$ 23.21	$ 23.51
Total unrecognized compensation expense remaining	$ 56
Weighted-average years expected to be recognized over	1 year 7 months 6 days
Cash-settled awards
Stock-based Payment Award
Non-vested as of January 1, 2018	0.1
Nonvested as of January 1, 2018, weighted-average grant date fair value	$ 23.47
Granted	0
Granted, Weighted-average grant-date fair value	$ 22.83	$ 23.62	$ 23.33
Vested	0
Vested, Weighted-average grant date fair value	$ 23.53
Forfeited	0
Forfeited, Weighted-average grant date fair value	$ 22.84
Non-vested as of December 31, 2018	0.1	0.1
Nonvested as of December 31, 2018, weighted-average grant date fair value	$ 23.20	$ 23.47
Total unrecognized compensation expense remaining	$ 1.2
Weighted-average years expected to be recognized over	1 year 6 months
Cash awards granted during the period target value	$ 22.3	$ 20.9	$ 2.8
Incentive compensation expense, non share-based	$ 15.6	$ 7	$ 2.5
Performance-based awards
Stock-based Payment Award
Non-vested as of January 1, 2018	7
Nonvested as of January 1, 2018, weighted-average grant date fair value	$ 21.10
Granted	2.1
Granted, Weighted-average grant-date fair value	$ 20.16	$ 21.13	$ 20.06
Vested	(2.9)
Vested, Weighted-average grant date fair value	$ 19.93
Forfeited	(0.6)
Forfeited, Weighted-average grant date fair value	$ 21.01
Non-vested as of December 31, 2018	5.6	7
Nonvested as of December 31, 2018, weighted-average grant date fair value	$ 21.36	$ 21.10
Total unrecognized compensation expense remaining	$ 45.7
Weighted-average years expected to be recognized over	1 year 8 months 12 days
Cash awards granted during the period target value	$ 40.7	$ 39.9	$ 38.4
Incentive compensation expense, non share-based	$ 39.9	$ 37.6	$ 35.3

Incentive Compensation Plans Em

Incentive Compensation Plans Employee Stock Purchase Plans (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2016
Employee Stock Ownership Plan (ESOP), Shares in ESOP [Abstract]
Maximum employee subscription rate	10.00%
Maximum number of shares per employee	900
Employee stock purchase plan description	90% of the lesser of the average market price of a share on the first business day of the offering period or the average market price of a share on the last business day of the offering period of three months
Employee Stock Purchase Plan, stock issued, shares	1,100,000	3,000,000
Employee Stock Purchase Plan, stock reserved for issuance, shares	10,000,000

Fair Value on a Recurring Basis

Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Fair value assets and liabilities measured on recurring basis
Cash equivalents		$ 786	$ 132.1
Contingent acquisition obligations	[1]	114.1	148.4
Contingent acquisition obligation, total change		(34.3)
Level 1
Fair value assets and liabilities measured on recurring basis
Cash equivalents		786	132.1
Contingent acquisition obligations	[1]	0	0
Level 2
Fair value assets and liabilities measured on recurring basis
Cash equivalents		0	0
Contingent acquisition obligations	[1]	0	0
Level 3
Fair value assets and liabilities measured on recurring basis
Cash equivalents		0	0
Contingent acquisition obligations	[1]	$ 114.1	$ 148.4
[1]	Contingent acquisition obligations includes deferred acquisition payments and unconditional obligations to purchase additional noncontrolling equity shares of consolidated subsidiaries. Fair value measurement of the obligations is based upon actual and projected operating performance targets as specified in the related agreements. The decrease in this balance of $34.3 from December 31, 2018 to December 31, 2019 is primarily due to payments and a reclassification from an arrangement during the second quarter of 2019. The amounts payable within the next twelve months are classified in accrued liabilities; any amounts payable thereafter are classified in other non-current liabilities.

Fair Value on a Nonrecurring Ba

Fair Value on a Nonrecurring Basis (Details) $ in Millions	Dec. 31, 2019USD ($)
Fair value assets and liabilities measured on nonrecurring basis
Long-term debt, fair value	$ 3,565.5
Level 1
Fair value assets and liabilities measured on nonrecurring basis
Long-term debt, fair value	0
Level 2
Fair value assets and liabilities measured on nonrecurring basis
Long-term debt, fair value	3,520
Level 3
Fair value assets and liabilities measured on nonrecurring basis
Long-term debt, fair value	$ 45.5

Employee Benefits (Details)

Employee Benefits (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Retirement Benefits, Description [Abstract]
Number of participants domestic pension plan	3,200
Number of participants postretirement benefit plan	1,500
Deferred Compensation Arrangements [Abstract]
Deferred compensation and benefit liability balance	$ 197.5	$ 196.2
Deferred compensation and benefit arrangement expense	19.4	10	$ 18.5
Cash Surrender Value of Life Insurance	178.2	177.3
Long-Term Disability Plan [Abstract]
Long-term disability plan obligation	5.5	$ 5.9
Long term disability plan, income replacement benefit obligation	$ 0

Pension and Postretirement Bene

Pension and Postretirement Benefit Obligation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Benefit Obligation [Roll Forward]
Domestic Pension Plan Discount Rate	3.35%	4.35%
Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets (Period Start)	$ 453.7
Fair Value of Plan Assets (Period End)	$ 508.6	$ 453.7
Pension plans with underfunded or unfunded accumulated benefit obligation
Foreign Pension Plan Discount Rate	1.84%	2.61%
Domestic Plan [Member]
Benefit Obligation [Roll Forward]
Benefit obligation (period start)	$ 115.4	$ 125.4
Service cost	0	0	$ 0
Interest cost	4.8	4.5	5.1
Benefits Paid	(9.2)	(9.5)
Plan participant contributions	0	0
Actuarial losses (gains)	5.9	(5)
Settlements and curtailments	0	0
Foreign currency effect	0	0
Other	0	0
Benefit Obligation (Period End)	116.9	115.4	125.4
Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets (Period Start)	89.8	98.8
Actual return on plan assets	16.1	(8.1)
Plan participant contributions	0	0
Employer contributions	2.4	8.6
Benefits paid	(9.2)	(9.5)
Settlements	0	0
Foreign currency effect	0	0
Other	0	0
Fair Value of Plan Assets (Period End)	99.1	89.8	$ 98.8
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(17.8)	(25.6)
Amounts Recognized in Consolidated Balance Sheets
Non-current asset	0	0
Current liability	0	0
Non-current liability	(17.8)	(25.6)
Net liability recognized	(17.8)	(25.6)
Accumulated benefit obligation	116.9	115.4
Amounts recognized in Accumulated Other Comprehensive Loss, net
Net actuarial loss	54.2	60.4
Prior service cost (credit)	0	0
Total amount recognized	54.2	60.4
Pension plans with underfunded or unfunded accumulated benefit obligation
Aggregate projected benefit obligation	116.9	115.4
Aggregate accumulated benefit obligation	116.9	115.4
Aggregate fair value of plan assets	$ 99.1	$ 89.8
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.35%	4.35%	3.70%
Foreign Plan [Member]
Benefit Obligation [Roll Forward]
Benefit obligation (period start)	$ 496	$ 582.3
Service cost	4.8	5.4	$ 4.9
Interest cost	12.4	13.1	13.5
Benefits Paid	(27.8)	(27.4)
Plan participant contributions	0	0.1
Actuarial losses (gains)	42.7	(47.6)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	(0.7)	(5.8)
Foreign currency effect	13.8	(26.4)
Other	0	2.3
Benefit Obligation (Period End)	541.2	496	582.3
Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets (Period Start)	363.9	404.2
Actual return on plan assets	42	(8)
Plan participant contributions	0	0.1
Employer contributions	18	19.1
Benefits paid	(27.8)	(27.4)
Settlements	0	(4.6)
Foreign currency effect	13.4	(21.1)
Other	0	1.6
Fair Value of Plan Assets (Period End)	409.5	363.9	$ 404.2
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(131.7)	(132.1)
Amounts Recognized in Consolidated Balance Sheets
Non-current asset	10.1	8.6
Current liability	(5.8)	(6.2)
Non-current liability	(136)	(134.5)
Net liability recognized	(131.7)	(132.1)
Accumulated benefit obligation	538.6	493.2
Amounts recognized in Accumulated Other Comprehensive Loss, net
Net actuarial loss	183.2	165.6
Prior service cost (credit)	1.1	1.2
Total amount recognized	184.3	166.8
Pension plans with underfunded or unfunded accumulated benefit obligation
Aggregate projected benefit obligation	534.6	491.2
Aggregate accumulated benefit obligation	533.5	489.9
Aggregate fair value of plan assets	$ 392.7	$ 350.5
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	1.84%	2.61%	2.36%
Other Postretirement Benefits Plan [Member]
Benefit Obligation [Roll Forward]
Benefit obligation (period start)	$ 27.7	$ 31.8
Service cost	0	0	$ 0
Interest cost	1.2	1.1	1.3
Benefits Paid	(5.4)	(5.9)
Plan participant contributions	2	1.8
Actuarial losses (gains)	1.7	(1.1)
Settlements and curtailments	0	0
Foreign currency effect	0	0
Other	0	0
Benefit Obligation (Period End)	27.2	27.7	31.8
Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets (Period Start)	0	0
Actual return on plan assets	0	0
Plan participant contributions	2	1.8
Employer contributions	3.4	4.1
Benefits paid	(5.4)	(5.9)
Settlements	0	0
Foreign currency effect	0	0
Other	0	0
Fair Value of Plan Assets (Period End)	0	0	$ 0
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(27.2)	(27.7)
Amounts Recognized in Consolidated Balance Sheets
Non-current asset	0	0
Current liability	(2.7)	(2.9)
Non-current liability	(24.5)	(24.8)
Net liability recognized	(27.2)	(27.7)
Amounts recognized in Accumulated Other Comprehensive Loss, net
Net actuarial loss	4.7	3.1
Prior service cost (credit)	(0.1)	(0.3)
Total amount recognized	$ 4.6	$ 2.8
Pension plans with underfunded or unfunded accumulated benefit obligation
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.25%	4.30%	3.65%

Net Periodic Cost (Details)

Net Periodic Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Net Periodic Benefit Cost
Settlement and curtailment (gains) losses	$ 0	$ 1	$ (6.8)
Domestic Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	0	0	0
Interest cost	4.8	4.5	5.1
Expected return on plan assets	(5.9)	(6.6)	(6.2)
Settlement and curtailment (gains) losses	0	0	0
Amortization of:
Prior service cost (credit)	0	0	0
Net actuarial losses	1.9	1.6	1.5
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 0.8	$ (0.5)	$ 0.4
Discount rate	4.35%	3.70%	4.20%
Expected return on plan assets	7.00%	7.00%	7.00%
Interest crediting rate	5.10%	5.10%	5.10%
Discount rate	3.35%	4.35%	3.70%
Interest crediting rate	5.10%	5.10%	5.10%
Foreign Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	$ 4.8	$ 5.4	$ 4.9
Interest cost	12.4	13.1	13.5
Expected return on plan assets	(17.4)	(18.8)	(17.7)
Settlement and curtailment (gains) losses	0	(1)	6.8
Amortization of:
Prior service cost (credit)	0.1	0.1	0.1
Net actuarial losses	4.8	5.9	5.5
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 4.7	$ 4.7	$ 13.1
Discount rate	2.61%	2.36%	2.52%
Rate of compensation increase	2.58%	2.37%	2.36%
Expected return on plan assets	4.76%	4.70%	4.66%
Interest crediting rate	1.44%	1.31%	1.29%
Discount rate	1.84%	2.61%	2.36%
Rate of compensation increase	2.51%	2.58%	2.37%
Interest crediting rate	1.37%	1.44%	1.31%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	$ 0	$ 0	$ 0
Interest cost	1.2	1.1	1.3
Expected return on plan assets	0	0	0
Settlement and curtailment (gains) losses	0	0	0
Amortization of:
Prior service cost (credit)	(0.2)	(0.2)	(0.2)
Net actuarial losses	0.1	0.1	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 1.1	$ 1	$ 1.1
Discount rate	4.30%	3.65%	4.05%
Discount rate	3.25%	4.30%	3.65%
Health care cost trend rate assumed for next year	7.00%	6.25%	6.50%
Year ultimate rate is reached	2028	2024	2024
Ultimate rate	5.00%	5.00%	5.00%

Fair Value of Pension Plan Asse

Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	$ 508.6	$ 453.7
Investment funds
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	18	13
Limited partnerships
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	25.6	25.6
Fixed income securities
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	19.6	23.1
Insurance contracts
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	5.5	5.8
Other plan assets
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	27.8	20
Total plan assets subject to leveling
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	96.5	87.5
Investments measured at net asset value
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	412.1	366.2
Level 1 | Investment funds
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	18	13
Level 1 | Limited partnerships
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 1 | Fixed income securities
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	19.6	23.1
Level 1 | Insurance contracts
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 1 | Other plan assets
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	27.8	20
Level 1 | Total plan assets subject to leveling
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	65.4	56.1
Level 2 | Investment funds
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 2 | Limited partnerships
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 2 | Fixed income securities
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 2 | Insurance contracts
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	5.5	5.8
Level 2 | Other plan assets
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 2 | Total plan assets subject to leveling
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	5.5	5.8
Level 3 | Investment funds
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 3 | Limited partnerships
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	25.6	25.6
Balance at beginning of period	25.6	29.5
Actual return on plan assets	0	(3.9)
Balance at end of period	25.6	25.6
Level 3 | Fixed income securities
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 3 | Insurance contracts
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 3 | Other plan assets
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	0	0
Level 3 | Total plan assets subject to leveling
Fair value assets and liabilities measured on recurring basis
Defined Benefit Plan, Plan Assets, Amount	$ 25.6	$ 25.6

Employee Benefits Allocation of

Employee Benefits Allocation of Plan Assets (Details)	Dec. 31, 2019	Dec. 31, 2018
Allocation of Plan Assets
Defined benefit plan, plan assets, target allocation, percentage	100.00%
Defined benefit plan, actual plan asset allocations	100.00%	100.00%
Alternative Investments
Allocation of Plan Assets
Defined benefit plan, plan assets, target allocation, percentage	25.00%
Defined benefit plan, actual plan asset allocations	25.00%	26.00%
Equity securities
Allocation of Plan Assets
Defined benefit plan, plan assets, target allocation, percentage	25.00%
Defined benefit plan, actual plan asset allocations	25.00%	22.00%
Fixed income securities
Allocation of Plan Assets
Defined benefit plan, plan assets, target allocation, percentage	20.00%
Defined benefit plan, actual plan asset allocations	19.00%	21.00%
Liability driven investments
Allocation of Plan Assets
Defined benefit plan, plan assets, target allocation, percentage	14.00%
Defined benefit plan, actual plan asset allocations	14.00%	16.00%
Real estate
Allocation of Plan Assets
Defined benefit plan, plan assets, target allocation, percentage	9.00%
Defined benefit plan, actual plan asset allocations	9.00%	6.00%
Other plan assets
Allocation of Plan Assets
Defined benefit plan, plan assets, target allocation, percentage	7.00%
Defined benefit plan, actual plan asset allocations	8.00%	9.00%

Pension Cash Flows (Details)

Pension Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans
Estimated U.S. federal subsidies expected to be received under the Medicare Prescription Drug, Improvement and Modernization Act of 2003, no more than	$ 0.3
Domestic Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer contributions	2.4	$ 8.6
Defined benefit plan, estimated future employer contributions in next fiscal year	3
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
Expected future benefit payments in 2019	14.6
Expected future benefit payments in 2020	8
Expected future benefit payments in 2021	8.1
Expected future benefit payments in 2022	7.6
Expected future benefit payments in 2023	7.5
Expected future benefit payments in 2024-2025	34.6
Foreign Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer contributions	18	19.1
Defined benefit plan, estimated future employer contributions in next fiscal year	18
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
Expected future benefit payments in 2019	21.7
Expected future benefit payments in 2020	19.8
Expected future benefit payments in 2021	21
Expected future benefit payments in 2022	21.9
Expected future benefit payments in 2023	22.7
Expected future benefit payments in 2024-2025	116.7
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer contributions	3.4	$ 4.1
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
Expected future benefit payments in 2019	2.7
Expected future benefit payments in 2020	2.6
Expected future benefit payments in 2021	2.4
Expected future benefit payments in 2022	2.2
Expected future benefit payments in 2023	2.1
Expected future benefit payments in 2024-2025	$ 8.8

Savings Plans (Details)

Savings Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Domestic Tax Authority
Defined Benefit Plans and Other Postretirement Benefit Plans
Cost Recognized	$ 61.2	$ 52.6	$ 47.2
Discretionary Company Contribution
Defined Benefit Plans and Other Postretirement Benefit Plans
Cost Recognized	8.1	6.7	3.6
Defined Contribution Plans Participant Forfeitures
Defined Benefit Plans and Other Postretirement Benefit Plans
Cost Recognized	5.6	5.8	4.6
Foreign Tax Authority
Defined Benefit Plans and Other Postretirement Benefit Plans
Cost Recognized	$ 54.5	$ 51.3	$ 47.4

Segment Operations (Details)

Segment Operations (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)business	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Segments:
Number of Reportable Segments | business									2
EBITA									$ 1,172	$ 1,046.4	$ 959.5
Total (expenses) and other income	$ (63.5)	$ (47.6)	$ (47.7)	$ (48.9)	$ (55.2)	$ (37.6)	$ (37.7)	$ (40.3)	(207.7)	(170.8)	(97.6)
Total revenue	2,901.8	2,438.1	2,520.2	2,361.2	2,856	2,297.5	2,391.8	2,169.1	10,221.3	9,714.4	9,047.6
Net revenue	2,433	2,061.4	2,125.9	2,004.8	2,413.7	1,895.7	1,948.2	1,774	8,625.1	8,031.6	7,473.5
Operating Income (Loss)	491.3	280.3	264.2	50.2	459.1	261.7	249.2	38.8	1,086	1,008.8	938.4
Amortization of Intangible Assets									86	37.6	21.1
Interest expense									(199.3)	(123)	(90.8)
Interest income									34.5	21.8	19.4
Other expense, net	(24.8)	$ (7.4)	$ (3.8)	$ (6.9)	(13.6)	$ (15.3)	$ (16.3)	$ (24.4)	(42.9)	(69.6)	(26.2)
Income before income taxes									878.3	838	840.8
Depreciation and amortization									192.5	165.3	136
Capital expenditures									198.5	177.1	155.9
Assets	17,751.9				15,620.3				17,751.9	15,620.3
IAN
Segments:
EBITA									1,110.4	1,042.1	891.7
Total revenue									8,026.4	7,556.1	7,009.6
Net revenue									7,348.2	6,767.5	6,266.7
Amortization of Intangible Assets									81.6	32.3	16.6
Depreciation and amortization									166	136.8	108.9
Capital expenditures									161.8	143.9	112
Assets	15,170.3				13,867.9				15,170.3	13,867.9
CMG
Segments:
EBITA									163.4	180.3	194.4
Total revenue									2,194.9	2,158.3	2,038
Net revenue									1,276.9	1,264.1	1,206.8
Amortization of Intangible Assets									4.4	5.3	4.5
Depreciation and amortization									19.2	19	19
Capital expenditures									13.3	13	17.7
Assets	1,710.4				1,516.7				1,710.4	1,516.7
Corporate and Other
Segments:
EBITA									(101.8)	(176)	(126.6)
Amortization of Intangible Assets									0	0	0
Depreciation and amortization									7.3	9.5	8.1
Capital expenditures									23.4	20.2	$ 26.2
Assets	$ 871.2				$ 235.7				$ 871.2	$ 235.7

Segment Information Major Geogr

Segment Information Major Geographic Area (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues and Long-Lived Assets
Long-Lived Assets	$ 2,843.8				$ 1,219.7				$ 2,843.8	$ 1,219.7
Net revenue	2,433	$ 2,061.4	$ 2,125.9	$ 2,004.8	2,413.7	$ 1,895.7	$ 1,948.2	$ 1,774	8,625.1	8,031.6	$ 7,473.5
Domestic
Revenues and Long-Lived Assets
Long-Lived Assets	2,080.4				892.9				2,080.4	892.9
Total International
Revenues and Long-Lived Assets
Long-Lived Assets	763.4				326.8				763.4	326.8
Net revenue									3,239	3,206.6	3,014.7
United Kingdom
Revenues and Long-Lived Assets
Long-Lived Assets	167.6				57.9				167.6	57.9
Net revenue									727	711.7	613.1
Continental Europe
Revenues and Long-Lived Assets
Long-Lived Assets	149.7				57.9				149.7	57.9
Net revenue									742.4	737.5	687.8
Asia Pacific
Revenues and Long-Lived Assets
Long-Lived Assets	240.9				121.7				240.9	121.7
Net revenue									858.3	896.8	866.9
Latin America
Revenues and Long-Lived Assets
Long-Lived Assets	74.8				43.6				74.8	43.6
Net revenue									389.9	350.1	350.8
Other
Revenues and Long-Lived Assets
Long-Lived Assets	$ 130.4				$ 45.7				130.4	45.7
Net revenue									$ 521.4	$ 510.5	$ 496.1

Guarantees (Details)

Guarantees (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Parent company guarantees on lease obligations	$ 739.1	$ 824.5
Parent company guarantees relating to credit facilities	293.8	349.1
Cash pooling guarantees	207.7	$ 207.8
Assets pledged as security for parent company guarantees	$ 0

Contingent Acquisition Obligati

Contingent Acquisition Obligations (Details) $ in Millions	Dec. 31, 2019USD ($)
Deferred acquisition payments
Business Acquisition, Contingent Consideration [Line Items]
Future contingent acquisition obligation due in 2018	$ 45.7
Future contingent acquisition obligation due in 2019	30.4
Future contingent acquisition obligation due in 2020	7.4
Future contingent acquisition obligation due in 2021	4.4
Future contingent acquisition obligation due in 2022	2.4
Future contingent acquisition obligation due thereafter	0
Future contingent acquisition obligation due, total	90.3
Redeemable noncontrolling interests and call options with affiliates
Business Acquisition, Contingent Consideration [Line Items]
Future contingent acquisition obligation due in 2018	26.2
Future contingent acquisition obligation due in 2019	37.9
Future contingent acquisition obligation due in 2020	32.4
Future contingent acquisition obligation due in 2021	6.2
Future contingent acquisition obligation due in 2022	2.5
Future contingent acquisition obligation due thereafter	0.2
Future contingent acquisition obligation due, total	105.4
Redeemable at noncontrolling equity owners discretion
Business Acquisition, Contingent Consideration [Line Items]
Future contingent acquisition obligation due in 2018	21.5
Total contingent acquisition payments
Business Acquisition, Contingent Consideration [Line Items]
Future contingent acquisition obligation due in 2018	71.9
Future contingent acquisition obligation due in 2019	68.3
Future contingent acquisition obligation due in 2020	39.8
Future contingent acquisition obligation due in 2021	10.6
Future contingent acquisition obligation due in 2022	4.9
Future contingent acquisition obligation due thereafter	0.2
Future contingent acquisition obligation due, total	$ 195.7

Results by Quarter (Unaudited_3

Results by Quarter (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net revenue	$ 2,433	$ 2,061.4	$ 2,125.9	$ 2,004.8	$ 2,413.7	$ 1,895.7	$ 1,948.2	$ 1,774	$ 8,625.1	$ 8,031.6	$ 7,473.5
Billable expenses	468.8	376.7	394.3	356.4	442.3	401.8	443.6	395.1	1,596.2	1,682.8	1,574.1
Total revenue	2,901.8	2,438.1	2,520.2	2,361.2	2,856	2,297.5	2,391.8	2,169.1	10,221.3	9,714.4	9,047.6
Salaries and related expenses	1,432.1	1,334.4	1,381.2	1,421.1	1,423.7	1,251.4	1,292.9	1,330.3	5,568.8	5,298.3	4,990.7
Office and other direct expenses	419.7	367.9	387.3	389.2	381	317	333.3	323.8	1,564.1	1,355.1	1,269.2
Billable expense	468.8	376.7	394.3	356.4	442.3	401.8	443.6	395.1	1,596.2	1,682.8	1,574.1
Cost of services	2,320.6	2,079	2,162.8	2,166.7	2,247	1,970.2	2,069.8	2,049.2	8,729.1	8,336.2	7,834
Acxiom Acquisition Costs					22.6	11	1.4
Depreciation and amortization	65.4	69	73	71.1	68.9	44	44	46	278.5	202.9	157.1
Restructuring Charges	0	0	2.1	31.8	0	0	0	0	33.9	0	(0.4)
Total operating expenses	2,410.5	2,157.8	2,256	2,311	2,396.9	2,035.8	2,142.6	2,130.3	9,135.3	8,705.6	8,109.2
Operating Income (Loss)	491.3	280.3	264.2	50.2	459.1	261.7	249.2	38.8	1,086	1,008.8	938.4
Net losses on sales of businesses	23.9	7.7	3.2	8.6	11.9	5.8	19.8	24.4	(43.4)	(61.9)	(24.1)
Tax Adjustments, Settlements, and Unusual Provisions			13.9
reversal of valuation allowance	25.3
Total (expenses) and other income	(63.5)	(47.6)	(47.7)	(48.9)	(55.2)	(37.6)	(37.7)	(40.3)	(207.7)	(170.8)	(97.6)
Various Discrete Tax Items					23.4
NET INCOME	342.2	168.4	172.8	(9.5)	342.5	163.5	147.8	(16.1)	$ 673.9	$ 637.7	$ 570.4
Net income available to IPG common stockholders	$ 328.9	$ 165.6	$ 169.5	$ (8)	$ 326.2	$ 161	$ 145.8	$ (14.1)
Earnings per share, Basic	$ 0.85	$ 0.43	$ 0.44	$ (0.02)	$ 0.85	$ 0.42	$ 0.38	$ (0.04)	$ 1.70	$ 1.61	$ 1.42
Earnings per share, Diluted	0.84	0.42	0.43	(0.02)	0.84	0.41	0.37	(0.04)	$ 1.68	$ 1.59	$ 1.40
Dividends declared per common share	$ 0.235	$ 0.235	$ 0.235	$ 0.235	$ 0.210	$ 0.210	$ 0.210	$ 0.210

Subsequent Events (Details)

Subsequent Events (Details)	Feb. 12, 2020$ / shares
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends payable, amount per share	$ 0.255

Restructuring Charges (Details)

Restructuring Charges (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Segment Reporting Information [Line Items]
Severance and termination costs									$ 22	$ 0	$ 0
Lease restructuring costs									11.9	0	(0.4)
Total Restructuring Charges	$ 0	$ 0	$ 2.1	$ 31.8	$ 0	$ 0	$ 0	$ 0	$ 33.9	0	$ (0.4)
Restructuring and Related Cost, Number of Positions Eliminated									627
Payments for Restructuring									$ 20.4
Restructuring Reserve	$ 1.6				$ 0				1.6	$ 0
CMG [Member]
Segment Reporting Information [Line Items]
Total Restructuring Charges									5.6
IAN [Member]
Segment Reporting Information [Line Items]
Total Restructuring Charges									$ 27.6

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease, Liability, Leases Not Commenced	$ 238
Operating Leases, Future Minimum Payments Due, Gross Rent, Current			$ 352
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Current			(7.7)
Operating Leases, Future Minimum Payments Due, Next Twelve Months			344.3
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	333.5
Operating Lease, Expense	$ 325.2
Minimum Remaining Lease Term	1 year
Maximum Remaining Lease Term	20 years
Short-term Lease, Cost	$ 13.8
Sublease Income	(12.9)
Lease, Cost	326.1
Operating Lease, Payments	334.1
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 422.8
Operating Lease, Weighted Average Remaining Lease Term	8 years
Operating Lease, Weighted Average Discount Rate, Percent	4.26%
Lessee, Operating Lease, Liability, Payments, Due Year Two	$ 300.7
Lessee, Operating Lease, Liability, Payments, Due Year Three	267.5
Lessee, Operating Lease, Liability, Payments, Due Year Four	209.7
Lessee, Operating Lease, Liability, Payments, Due Year Five	183.5
Lessee, Operating Lease, Liability, Payments, Due after Year Five	716.1
Lessee, Operating Lease, Liability, Payments, Due	2,011
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	314.2
Operating Lease, Liability	1,696.8	$ 1,544.4
Operating Lease, Liability, Current	267.2		0
Operating Lease, Liability, Noncurrent	$ 1,429.6		0
Operating Leases, Future Minimum Payments, Gross Rent, Due in Two Years			324.3
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Two Years			(5.2)
Operating Leases, Future Minimum Payments, Due in Two Years			319.1
Operating Leases, Future Minimum Payments, Gross Rent, Due in Three Years			282.3
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Three Years			(2.2)
Operating Leases, Future Minimum Payments, Due in Three Years			280.1
Operating Leases, Future Minimum Payments, Gross Rent, Due in Four Years			242.5
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Four Years			(1.3)
Operating Leases, Future Minimum Payments, Due in Four Years			241.2
Operating Leases, Future Minimum Payments, Gross Rent, Due in Five Years			184
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Five Years			(0.6)
Operating Leases, Future Minimum Payments, Due in Five Years			183.4
Operating Leases, Future Minimum Payments, Gross Rent, Due Thereafter			714.6
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due Thereafter			(0.5)
Operating Leases, Future Minimum Payments, Due Thereafter			714.1
Operating Leases, Future Minimum Payments Due, Gross Rent			2,099.7
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals			(17.5)
Operating Leases, Future Minimum Payments Due			$ 2,082.2
Minimum Lease Term for Leases That Have Not Yet Commenced	4 years
Maximum Lease Term for Leases That Have Not Yet Commenced	15 years