Omnicom (OMC) 10-Q 17 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	9 Months Ended
	Sep. 30, 2013	Oct. 15, 2013
Entity Information [Line Items]
Entity Registrant Name	OMNICOM GROUP INC.
Entity Central Index Key	29989
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		257,360,875

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Current Assets:
Cash and cash equivalents	$1,521.50	$2,678.30
Short-term investments, at cost	12.9	20.6
Accounts receivable, net of allowance for doubtful accounts of $32.8 and $35.9	6,577.80	6,958.20
Work in process	1,328.30	1,008.40
Other current assets	1,024.90	995.9
Total Current Assets	10,465.40	11,661.40
Property and Equipment at cost, less accumulated depreciation of $1,226.7 and $1,234.8	701.6	723.8
Equity Method Investments	152.2	155.2
Goodwill	8,869	8,844.20
Intangible Assets, net of accumulated amortization of $552.9 and $498.0	398.1	456.1
Other Assets	284.5	311.2
TOTAL ASSETS	20,870.80	22,151.90
Current Liabilities:
Accounts payable	7,533.10	8,296.70
Customer advances	1,280.40	1,231.50
Current portion of debt	0.3	0.4
Short-term borrowings	18.3	6.4
Taxes payable	234.9	264.4
Other current liabilities	2,168.40	2,076.40
Total Current Liabilities	11,235.40	11,875.80
Long-Term Notes Payable	3,782.70	3,789.10
Convertible Debt	252.7	659.4
Long-Term Liabilities	718	739.9
Long-Term Deferred Tax Liabilities	879.3	933
Commitments and Contingent Liabilities (See Note 12)
Temporary Equity - Redeemable Noncontrolling Interests	194.7	198.4
Shareholders’ Equity:
Preferred stock	0	0
Common stock	59.6	59.6
Additional paid-in capital	810.9	836.6
Retained earnings	8,766.70	8,394.40
Accumulated other comprehensive income (loss)	-220.6	-129.5
Treasury stock, at cost	-6,076.30	-5,700.30
Total Shareholders’ Equity	3,340.30	3,460.80
Noncontrolling interests	467.7	495.5
Total Equity	3,808	3,956.30
TOTAL LIABILITIES AND EQUITY	$20,870.80	$22,151.90

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Allowance for doubtful accounts	$32.80	$35.90
Accumulated depreciation	1,226.70	1,234.80
Intangible assets, accumulated amortization	$552.90	$498

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue	$3,490.50	$3,406.60	$10,526.40	$10,274.80
Operating Expenses	3,111.10	3,019.30	9,252.20	9,018.60
Operating Income	379.4	387.3	1,274.20	1,256.20
Interest Expense	50.5	47.8	148.8	130.3
Interest Income	7.7	7.5	24.2	26
Income Before Income Taxes and Income From Equity Method Investments	336.6	347	1,149.60	1,151.90
Income Tax Expense	116.2	118.7	388.9	389.9
Income From Equity Method Investments	4.3	5.3	10.5	11.9
Net Income	224.7	233.6	771.2	773.9
Less: Net Income Attributed To Noncontrolling Interests	28.7	29.7	80.5	82.7
Net Income - Omnicom Group Inc.	$196	$203.90	$690.70	$691.20
Net Income Per Share - Omnicom Group Inc.:
Basic	$0.74	$0.75	$2.60	$2.51
Diluted	$0.74	$0.74	$2.58	$2.49
Dividends Declared Per Common Share	$0.40	$0.30	$1.20	$0.90

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Income	$224.70	$233.60	$771.20	$773.90
Unrealized gain on available-for-sale securities, net of income taxes of $0.2 for the nine months ended September 30, 2013	0	0	0.3	0
Foreign currency translation adjustment, net of income taxes of $94.4 and $53.2 for the three months and ($63.6) and $36.9 for the nine months ended September 30, 2013 and 2012, respectively	183.4	103.2	-123.3	71.3
Defined benefit pension and postemployment plans adjustment, net of income taxes of $0.7 and $0.9 for the three months and $3.1 and $2.5 for the nine months ended September 30, 2013 and 2012, respectively	1.1	1.3	4.5	3.7
Other Comprehensive Income	184.5	104.5	-118.5	75
Comprehensive Income	409.2	338.1	652.7	848.9
Less: Comprehensive Income attributed to noncontrolling interests	36.4	38.7	53.1	86.7
Comprehensive Income - Omnicom Group Inc.	$372.80	$299.40	$599.60	$762.20

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Unrealized gain on available-for-sale securities, income taxes	$0	$0	$0.20	$0
Foreign currency transaction and translation adjustments, income taxes	94.4	53.2	-63.6	36.9
Defined benefit plans adjustment, income taxes	$0.70	$0.90	$3.10	$2.50

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash Flows from Operating Activities:
Net Income	$771.20	$773.90
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	136.6	135.4
Amortization of intangible assets	76.3	75.2
Amortization of deferred gain from termination of interest rate swaps	-5.5	-5.5
Income from equity method investments, net of dividends received	0.4	-1.6
Provision for doubtful accounts	4.4	5.3
Share-based compensation	64.9	63.1
Excess tax benefit from share-based compensation	-34.2	-79.8
Change in operating capital	-654.2	-665.9
Net Cash Provided By Operating Activities	359.9	300.1
Cash Flows from Investing Activities:
Payments to acquire property and equipment	-123.3	-158.7
Payments to acquire businesses and interests in affiliates, net of cash acquired	-26.5	-117.3
Proceeds from investments	17.3	8.4
Net Cash Used In Investing Activities	-132.5	-267.6
Cash Flows from Financing Activities:
Proceeds from short-term debt	12.5	1.4
Proceeds from borrowings	0	1,273.20
Redemption of convertible debt	-406.7	0
Payments of dividends	-212.6	-235.4
Payments for repurchase of common stock	-571.3	-1,001.60
Proceeds from stock plans	44.8	207.6
Payments for acquisition of additional noncontrolling interests	-11	-19.2
Payments of dividends to noncontrolling interest shareholders	-81.1	-78.9
Payments of contingent purchase price obligations	-68.9	-30.6
Excess tax benefit on share-based compensation	34.2	79.8
Other, net	-24.2	-86.9
Net Cash (Used In) Provided By Financing Activities	-1,284.30	109.4
Effect of exchange rate changes on cash and cash equivalents	-99.9	33.2
Net (Decrease) Increase in Cash and Cash Equivalents	-1,156.80	175.1
Cash and Cash Equivalents at the Beginning of the Period	2,678.30	1,781.20
Cash and Cash Equivalents at the End of the Period	$1,521.50	$1,956.30

Presentation_of_Financial_Stat

Presentation of Financial Statements	9 Months Ended
	Sep. 30, 2013
Presentation of Financial Statements [Abstract]
Presentation of Financial Statements	Presentation of Financial Statements
	The terms “Omnicom,”, the “Company”, “we,” “our” and “us” each refer to Omnicom Group Inc. and our subsidiaries, unless the context indicates otherwise. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP” or “GAAP”) for interim financial information and Article 10 of Regulation S-X of the Securities and Exchange Commission. Accordingly, certain information and footnote disclosure have been condensed or omitted.
	In our opinion, the accompanying unaudited condensed financial statements reflect all adjustments, consisting of normal recurring accruals, considered necessary for a fair presentation, in all material respects, of the information contained herein. These unaudited condensed financial statements should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2012 (“2012 Form 10-K”). Results for the interim periods are not necessarily indicative of results that may be expected for the year.

Business_Combination_Agreement

Business Combination Agreement	9 Months Ended
	Sep. 30, 2013
Business Combination Agreement [Abstract]
Mergers, Acquisitions and Dispositions Disclosures [Text Block]	2. Business Combination Agreement
	On July 27, 2013, the Company and Publicis Groupe S.A. (“Publicis”) entered into a Business Combination Agreement (the “Agreement”) pursuant to which the Company and Publicis agreed, subject to the terms and conditions of the Agreement, to combine their respective businesses (the “Business Combination”). In the Business Combination, Publicis will merge (the “Publicis Merger”) with and into Publicis Omnicom Group N.V., a newly-formed Dutch holding company (“Publicis Omnicom Group” or “HoldCo”), with Publicis Omnicom Group being the surviving entity in the Publicis Merger, and immediately after consummation of the Publicis Merger, a corporation wholly-owned by Publicis Omnicom Group will merge (the “Omnicom Merger” and together with the Publicis Merger, the “Mergers”) with and into the Company, with the Company being the surviving corporation in the Omnicom Merger.
	In the Publicis Merger, each issued and outstanding share of Publicis will be exchanged for 1.000000 ordinary share of Publicis Omnicom Group. In addition, prior to completion of the Publicis Merger, Publicis intends to declare and pay a special dividend, in cash, in an amount equal to €1.00 per Publicis share (the “Publicis Transaction Dividend”). In the Omnicom Merger, each share of common stock of the Company will be converted into the right to receive 0.813008 of a Publicis Omnicom Group ordinary share, together with cash in lieu of fractional shares, subject to adjustment to account for certain changes in outstanding shares and certain excluded asset values as set forth in the Agreement. Similarly, prior to completion of the Omnicom Merger, the Company intends to declare and pay a special cash dividend of $2.00 per share of the Company’s outstanding common stock (the “Omnicom Transaction Dividend” and, together with the Publicis Transaction Dividend, the “Transaction Dividends”), subject to adjustment to account for certain changes in outstanding shares of the parties and certain excluded asset values, in each case as set forth in the Agreement, and, if necessary, to equalize the cumulative amount of regular dividends paid by the Company after July 27, 2013 with the cumulative amount of regular Publicis dividends paid after July 27, 2013. However, dividends of up to $0.80 in the aggregate paid to holders of the Company’s common stock in respect of record dates after July 27, 2013 and before the Mergers are not included in this equalization. The payment of the Transaction Dividends is also subject to applicable law.
	Completion of the transactions contemplated by the Agreement (which include the Mergers, the Publicis Transaction Dividend, and the Omnicom Transaction Dividend, collectively, the “Transactions”) will be subject to the satisfaction or waiver, if legally permitted, of certain conditions including (a) approval and adoption of the Agreement and the Omnicom Merger by the holders of two-thirds of the outstanding shares of common stock of the Company, approval of the Cross-Border Merger Terms (as described in the Agreement), and the Publicis Merger by the holders of two-thirds of the voting rights attached to the Publicis shares present at a meeting of the Publicis shareholders, and the approval of the Publicis Transaction Dividend by the holders of a majority of the voting rights attached to the Publicis shares present at a meeting of the Publicis shareholders; (b) approval by requisite governmental regulators and authorities, including approvals under applicable competition laws; (c) the listing of the Publicis Omnicom Group ordinary shares on applicable stock exchanges; (d) the absence of any law or order prohibiting the completion of the Transactions; and (e) the absence of a material adverse effect on either the Company or Publicis.
	The completion of the Transactions contemplated by the Agreement will have a material effect on our future results of operations and financial position.

New_Accounting_Standards

New Accounting Standards	9 Months Ended
	Sep. 30, 2013
New Accounting Standards [Abstract]
New Accounting Standards	New Accounting Standards
	On January 1, 2013, we adopted FASB Accounting Standards Update (“ASU”) No. 2013-01, Balance Sheet (Topic 210): Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities (“ASU 2013-01”). ASU 2013-01 amended existing guidance by requiring additional disclosure about financial instruments and derivative instruments that are either (1) offset in the statement of financial position or (2) subject to an enforceable master netting arrangement. ASU 2013-01 requires retrospective disclosure for all comparative periods. The adoption of ASU 2013-01 did not have a material impact on our financial position or financial statement disclosure.
	As of March 31, 2013, we adopted FASB ASU 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income (“ASU 2013-02”). ASU 2013-02 amended existing guidance by requiring additional disclosure either on the face of the income statement or in the notes to the financial statements of significant amounts reclassified out of accumulated other comprehensive income. ASU 2013-02 required prospective adoption, and effected financial statement disclosure only. The adoption of ASU 2013-02 had no affect on our results of operations or financial position.

Net_Income_Per_Common_Share

Net Income Per Common Share	9 Months Ended
	Sep. 30, 2013
Net Income per Common Share [Abstract]
Net Income per Common Share	Net Income per Common Share
	Net income per common share is based on the weighted average number of common shares outstanding during each period. Diluted net income per common share is based on the weighted average number of common shares outstanding, plus, if dilutive, common share equivalents, which include outstanding stock options and restricted stock, and shares issuable for the conversion value of our convertible debt.
	Net income per common share is calculated using the two-class method, which is an earnings allocation method for computing net income per common share when a company’s capital structure includes common stock and participating securities. The majority of our unvested restricted stock awards receive non-forfeitable dividends at the same rate as our common stock and therefore are considered participating securities. Under the two-class method, basic and diluted net income per common share is reduced for a presumed hypothetical distribution of earnings to holders of our unvested restricted stock. The computation of basic and diluted net income per common share for the three and nine months ended September 30, 2013 and 2012 is (in millions, except per share amounts):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Net Income Available for Common Shares:
	Net income - Omnicom Group Inc.	$	196		$	203.9		$	690.7		$	691.2
	Net income allocated to participating securities	(4.8		)	(4.5		)	(18.1		)	(15.4		)
		$	191.2		$	199.4		$	672.6		$	675.8
	Weighted Average Shares:
	Basic	258.2			266.6			259			269.6
	Dilutive stock options and restricted shares and shares issuable for the conversion value of convertible debt	1.7			1.9			1.4			1.9
	Diluted	259.9			268.5			260.4			271.5
	Anti-dilutive stock options and restricted shares	—			0.2			0.1			0.2
	Net Income per Common Share - Omnicom Group Inc.:
	Basic	$	0.74		$	0.75		$	2.6		$	2.51
	Diluted	$	0.74		$	0.74		$	2.58		$	2.49

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets
	Goodwill and intangible assets at September 30, 2013 and December 31, 2012 were (in millions):
		2013								2012
		Gross			Accumulated			Net		Gross		Accumulated		Net
		Carrying			Amortization			Carrying		Carrying		Amortization		Carrying
		Value						Value		Value				Value
	Goodwill	$	9,450.60		$	581.6		$	8,869.00	$	9,424.30	$	580.1	$	8,844.20
	Intangible assets:
	Purchased and internally developed software	$	285.3		$	226.7		$	58.6	$	283.3	$	218.8	$	64.5
	Customer related and other	665.7			326.2			339.5		670.8		279.2		391.6
		$	951		$	552.9		$	398.1	$	954.1	$	498	$	456.1
	We evaluate goodwill for impairment at least annually at the end of the second quarter of the year and whenever events or circumstances indicate the carrying value may not be recoverable. At June 30, 2013, we performed Step 1 of the annual impairment test and compared the fair value of each of our reporting units to its respective carrying value, including goodwill. Based on the results of our impairment tests, we concluded that our goodwill was not impaired at June 30, 2013 because the fair value of each of our reporting units was substantially in excess of their respective net book value.
	Change in goodwill for the nine months ended September 30, 2013 and 2012 were (in millions):
		2013			2012
	Balance January 1	$	8,844.20		$	8,456.30
	Acquisitions	55.5			225.6
	Dispositions	(8.5		)	(2.5		)
	Foreign currency translation	(22.2		)	49.2
	Balance September 30	$	8,869.00		$	8,728.60
	There were no goodwill impairment losses recorded in the first nine months of 2013 or 2012 and there are no accumulated goodwill impairment losses. Goodwill resulting from acquisitions completed during 2013 and 2012 includes $9.2 million and $16.2 million, respectively, of goodwill attributed to noncontrolling interests in the acquired businesses.

Debt

Debt	9 Months Ended
	Sep. 30, 2013
Debt [Abstract]
Debt	Debt
	Lines of Credit
	We have committed and uncommitted lines of credit. We have a $2.5 billion committed line of credit (“Credit Agreement”) with a consortium of banks expiring on October 12, 2016. We have the ability to classify borrowings under the Credit Agreement as long-term. The Credit Agreement supports the issuance of up to $1.5 billion of commercial paper. Commercial paper issuances reduce the amount available under the Credit Agreement. At September 30, 2013, there were no outstanding commercial paper issuances or borrowings under the Credit Agreement. At September 30, 2013 and December 31, 2012, we had various uncommitted lines of credit aggregating $1,083.4 million and $878.2 million, respectively.
	Our available and unused lines of credit at September 30, 2013 and December 31, 2012 were (in millions):
		2013		2012
	Credit Agreement	$	2,500.00	$	2,500.00
	Uncommitted lines of credit	1,083.40		878.2
	Available and unused lines of credit	$	3,583.40	$	3,378.20
	The Credit Agreement contains financial covenants that restrict our ability to incur indebtedness as defined in the agreement. These financial covenants limit the Leverage Ratio of total consolidated indebtedness to total consolidated EBITDA to no more than 3 times for the most recently ended 12 month period (under the Credit Agreement, EBITDA is defined as earnings before interest, taxes, depreciation and amortization). We are also required to maintain a minimum Interest Coverage Ratio of consolidated EBITDA to interest expense of at least 5 times for the most recently ended 12 month period. At September 30, 2013 we were in compliance with these covenants, as our Leverage Ratio was 1.9 times and our Interest Coverage Ratio was 10.6 times. The Credit Agreement does not limit our ability to declare or pay dividends.
	Short-Term Borrowings
	Short-term borrowings of $18.3 million and $6.4 million at September 30, 2013 and December 31, 2012, respectively, represent bank overdrafts and credit lines of our international subsidiaries. The bank overdrafts and credit lines are treated as unsecured loans pursuant to the agreements supporting the facilities. Due to the short-term nature of these instruments, carrying value approximates fair value.
	Long-Term Notes Payable
	Long-term notes payable at September 30, 2013 and December 31, 2012 were (in millions):
		2013		2012
	5.90% Senior Notes due April 15, 2016	$	1,000.00	$	1,000.00
	6.25% Senior Notes due July 15, 2019	500		500
	4.45% Senior Notes due August 15, 2020	1,000.00		1,000.00
	3.625% Senior Notes due May 1, 2022	1,250.00		1,250.00
	Other notes and loans	0.3		0.4
		3,750.30		3,750.40
	Unamortized premium (discount) on Senior Notes, net	15		16
	Deferred gain from termination of interest rate swaps on Senior Notes due 2016	17.7		23.1
		3,783.00		3,789.50
	Less current portion	0.3		0.4
	Long-term notes payable	$	3,782.70	$	3,789.10
	Convertible Debt
	Convertible debt at September 30, 2013 and December 31, 2012 was (in millions):
		2013		2012
	Convertible Notes due July 31, 2032	$	252.7	$	252.7
	Convertible Notes due June 15, 2033	—		0.1
	Convertible Notes due July 1, 2038	—		406.6
		252.7		659.4
	Less current portion	—		—
	Convertible debt	$	252.7	$	659.4
	On May 16, 2013, we called our Convertible Notes due June 15, 2033 (“2033 Notes”) and our Convertible Notes due July 1, 2038 (“2038 Notes”) for redemption on June 17, 2013 at a redemption price of 100% of the principal amount. As provided in the indenture governing the 2033 Notes and the 2038 Notes, prior to redemption the noteholders had the right to convert their notes into shares of our common stock at a conversion rate of 19.4174 shares per $1,000 principal amount at any time prior to June 13, 2013. Substantially all the noteholders exercised their conversion right. We paid $406.1 million in cash representing the principal amount of the 2033 Notes and 2038 Notes that were converted and issued 1,499,792 shares of our common stock to satisfy the conversion premium. On June 17, 2013, we paid $0.6 million to redeem the remaining 2033 Notes and 2038 Notes that were not converted.
	Beginning August 1, 2013, our Convertible Notes due July 31, 2032 ("2032 Notes") will accrue contingent interest for the six-month period August 1, 2013 to January 31, 2014. Contingent interest of $2.81 per $1,000 principal amount is payable quarterly on October 31, 2013 and January 31, 2014. In the third quarter of 2013, we recorded a charge to interest expense of $2.8 million, representing the fair value of the contingent interest derivative. In addition, effective September 24, 2013, the conversion rate was adjusted to 18.249 shares of our common stock per $1,000 principal amount. The previous conversion rate was 18.18 shares of our common stock per $1,000 principal amount. On July 31, 2014, the holders of our 2032 Notes can put their notes back to us for cash

Segment_Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting
	Our wholly and partially owned agencies operate within the advertising, marketing and corporate communications services industry. These agencies are organized into agency networks, virtual client networks, regional reporting units and operating groups. Consistent with our fundamental business strategy, our agencies serve similar clients, in similar industries and, in many cases, the same clients across a variety of geographic regions. In addition, our agency networks have similar economic characteristics including similar costs and long-term profit contribution. The main economic components of each agency are employee compensation and related costs and direct service costs and office and general costs, which include rent and occupancy costs, technology costs and other overhead expenses. Therefore, given these similarities, we aggregate our operating segments, which are our five agency networks, into one reporting segment.
	Revenue and long-lived assets and goodwill by geographic area as of and for the periods ended September 30, 2013 and 2012 were (in millions):
		Americas		EMEA		Asia Pacific
	2013
	Revenue - Three months ended	$	2,054.40	$	1,050.80	$	385.3
	Revenue - Nine months ended	6,252.30		3,138.50		1,135.60
	Long-lived assets and goodwill	6,072.40		2,906.10		592.1
	2012
	Revenue - Three months ended	$	2,003.10	$	1,007.20	$	396.3
	Revenue - Nine months ended	6,073.80		3,072.80		1,128.20
	Long-lived assets and goodwill	6,088.50		2,738.10		602
	The Americas is composed of the United States, Canada and Latin American countries. EMEA is composed of various Euro currency countries, the United Kingdom, other European countries that have not adopted the European Union Monetary standard, the Middle-East and Africa. Asia Pacific is composed of Australia, China, India, Japan, Korea, New Zealand, Singapore and other Asian countries.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Taxes [Abstract]
Income Taxes	Income Taxes
	Our effective tax rate for the nine months ended September 30, 2013 and 2012 was 33.8%.
	In connection with the conversion of our 2033 Notes and 2038 Notes, we reclassified $52.7 million, representing the excess of the accreted value of the notes for income tax purposes over the conversion value, from long-term deferred tax liability to current taxes payable. In addition, we reclassified $34.5 million, representing the difference between the issue price of the notes and the conversion value, from long-term deferred tax liability to additional paid-in capital. In third quarter of 2013, we paid approximately $40 million of the tax liability resulting from the conversion of the notes and we expect to pay the remaining liability in the fourth quarter of 2013.
	At September 30, 2013, our unrecognized tax benefits were $141.5 million. Of this amount, approximately $62.8 million would affect our effective tax rate upon resolution of the uncertain tax positions.

Pension_and_Other_Postemployme

Pension and Other Postemployment Benefits	9 Months Ended
	Sep. 30, 2013
Pension and Other Postemployment Benefits [Abstract]
Pension and Other Postemployment Benefits	Pension and Other Postemployment Benefits
	Defined Benefit Pension Plans
	The components of net periodic benefit cost for the nine months ended September 30, 2013 and 2012 were (in millions):
		2013			2012
	Service cost	$	3.3		$	4.6
	Interest cost	4.6			4.6
	Expected return on plan assets	(2.1		)	(1.9		)
	Amortization of prior service cost	2.7			2.4
	Amortization of actuarial (gains) losses	2.4			1.1
		$	10.9		$	10.8
	We contributed $3.1 million and $5.3 million to our defined benefit pension plans in the nine months ended September 30, 2013 and 2012, respectively.
	Postemployment Arrangements
	The components of net periodic benefit cost for the nine months ended September 30, 2013 and 2012 were (in millions):
		2013			2012
	Service cost	$	3		$	3
	Interest cost	3.3			3.5
	Amortization of prior service cost	1.5			1.5
	Amortization of actuarial (gains) losses	1			0.6
		$	8.8		$	8.6
	Net periodic benefit cost for our defined benefit pension plans and postemployment arrangements is included in the salary and service costs component of operating expenses.

Operating_Expenses

Operating Expenses	9 Months Ended
	Sep. 30, 2013
Operating Expenses [Abstract]
Operating Expenses	Operating Expenses
	Operating expenses for the three and nine months ended September 30, 2013 and 2012 were (in millions):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2013		2012		2013		2012
	Salary and service costs	$	2,579.20	$	2,515.80	$	7,711.50	$	7,491.50
	Office and general expenses	503.8		503.5		1,512.60		1,527.10
	Merger expenses	28.1		—		28.1		—
	Operating expenses	$	3,111.10	$	3,019.30	$	9,252.20	$	9,018.60
	In the third quarter of 2013 we incurred $28.1 million of expenses in connection with the pending merger with Publicis, which were primarily comprised of professional fees. The merger expenses are shown as a separate component of operating expenses. We expect to incur significant additional merger expenses.

Supplemental_Cash_Flow

Supplemental Cash Flow	9 Months Ended
	Sep. 30, 2013
Supplemental Cash Flow [Abstract]
Supplemental Cash Flow	Supplemental Cash Flow Data
	Change in operating capital for the nine months ended September 30, 2013 and 2012 were (in millions):
		2013			2012
	(Increase) decrease in accounts receivable	$	294		$	438.1
	(Increase) decrease in work in process and other current assets	(392.8		)	(205.6		)
	Increase (decrease) in accounts payable	(668.9		)	(697.4		)
	Increase (decrease) in customer advances and other current liabilities	97.6			(314.5		)
	Change in other assets and liabilities, net	15.9			113.5
		$	(654.2	)	$	(665.9	)
	Income taxes paid	$	335.2		$	287.5
	Interest paid	$	134.8		$	114.8
	In connection with the conversion of our 2033 Notes and our 2038 Notes in May 2013, we issued 1,499,792 shares of our common stock to satisfy the conversion premium. These issuances resulted in a non-cash pre-tax financing activity of $95.4 million, excluding the cash tax benefit of $34.5 million, based on the closing prices of our common stock on the settlement dates.

Commitments_and_Contingent_Lia

Commitments and Contingent Liabilities	9 Months Ended
	Sep. 30, 2013
Commitments and Contingent Liabilities [Abstract]
Commitments and Contingent Liabilities	Commitments and Contingent Liabilities
	A putative class action challenging the merger was filed on August 5, 2013 on behalf of Omnicom shareholders in the Supreme Court of the State of New York, New York County. The action, entitled Paul Ansfield v. Wren, et al., names as defendants Omnicom and its board of directors, as well as Publicis and HoldCo. It alleges that the members of the Omnicom board breached their fiduciary duties by, inter alia, approving a merger that is purportedly detrimental to Omnicom’s shareholders.  The action also alleges that Publicis aided and abetted the Omnicom board’s breach of their fiduciary duties. The action seeks an injunction barring or rescinding the Business Combination, damages and attorneys’ fees and costs.
	Two additional purported class actions were subsequently filed in the Supreme Court of the State of New York, New York County: Lee and Lee v. Omnicom Group, et al., filed on August 14, 2013, and Fultz v. Crawford et al., filed on August 20, 2013. Both of these actions name as defendants Omnicom and its board of directors, as well as Publicis, and make substantially the same allegations and seek substantially the same relief as the Ansfield case.
	On August 19, 2013, the Plaintiffs in the Ansfield and Lee actions filed a motion to consolidate those actions with each other and with all subsequently filed or transferred actions arising out of the same facts and circumstances, to select plaintiffs as lead plaintiffs and to approve plaintiffs’ selection of counsel as co-lead counsel.  On October 3, 2013, the Plaintiffs in all three cases asked the Court to consolidate the three cases, and to approve lead plaintiffs and plaintiffs’ selection of counsel as co-lead counsel.
	Omnicom believes these lawsuits are without merit and intends to defend vigorously against them. Due to the inherent uncertainties of such matters, and because discovery is not yet completed, we are unable to predict potential outcomes or estimate of the range of potential damages, if any. Management does not presently expect that the outcome of these matters will have a material adverse effect on our results of operations or financial position.
	In the ordinary course of business, we are involved in various other legal proceedings. We do not presently expect that these other proceedings will have a material adverse effect on our results of operations or financial position.

Fair_Value

Fair Value	9 Months Ended
	Sep. 30, 2013
Fair Value [Abstract]
Fair Value	Fair Value
	Financial assets and liabilities measured at fair value on a recurring basis at September 30, 2013 and December 31, 2012 were (in millions):
	September 30, 2013	Level 1		Level 2		Level 3		Total
	Assets:
	Cash and cash equivalents	$	1,521.50					$	1,521.50
	Short-term investments	12.9						12.9
	Available-for-sale securities	4.6						4.6
	Forward foreign exchange contracts			$	1.3			1.3
	Liabilities:
	Forward foreign exchange contracts			$	0.3			$	0.3
	Contingent interest derivative			2.8				2.8
	Contingent purchase price obligations					$	213.3	213.3
	December 31, 2012	Level 1		Level 2		Level 3		Total
	Assets:
	Cash and cash equivalents	$	2,678.30					$	2,678.30
	Short-term investments	20.6						20.6
	Available-for-sale securities	3.9						3.9
	Forward foreign exchange contracts			$	0.5			0.5
	Liabilities:
	Contingent purchase price obligations					$	266.2	$	266.2
	The reduction in Level 3 contingent purchase price obligations from $266.2 million at December 31, 2012 to $213.3 million at September 30, 2013 resulted primarily from payments of $68.9 million.
	The carrying amount and fair value of our financial instruments at September 30, 2013 and December 31, 2012 were (in millions):
		2013				2012
		Carrying		Fair		Carrying		Fair
		Amount		Value		Amount		Value
	Assets:
	Cash and cash equivalents	$	1,521.50	$	1,521.50	$	2,678.30	$	2,678.30
	Short-term investments	12.9		12.9		20.6		20.6
	Forward foreign exchange contracts	1.3		1.3		0.5		0.5
	Available-for-sale securities	4.6		4.6		3.9		3.9
	Cost method investments	21.7		21.7		23.1		23.1
	Liabilities:
	Short-term borrowings	$	18.3	$	18.3	$	6.4	$	6.4
	Forward foreign exchange contracts	0.3		0.3		—		—
	Contingent interest derivative	2.8		2.8		—		—
	Contingent purchase price obligations	213.3		213.3		266.2		266.2
	Debt	4,035.70		4,250.70		4,448.90		4,857.30
	The estimated fair value of derivative positions in forward foreign exchange contracts is determined using model-derived valuations, taking into consideration market rates and counterparty credit risk. The estimated fair value of the contingent purchase price obligation is calculated in accordance with the terms of each acquisition agreement and are appropriately discounted. The fair value of debt is based on quoted market prices.

Changes_in_Accumulated_Other_C

Changes in Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2013
Changes in Accumulated Other Comprehensive Income (Loss) [Abstract]
Changes in Accumulated Other Comprehensive Income (Loss)	Changes in Accumulated Other Comprehensive Income (Loss)
	The changes in accumulated other comprehensive income (loss) for the nine months ended September 30, 2013 were (in millions):
		Unrealized Gain and (Loss) on Available-for-Sale Securities			Defined Benefit Pension and Postemployment Plans			Foreign Currency Translation			Total
	Balance January 1	$	(2.0	)	$	(89.8	)	$	(37.7	)	$	(129.5	)
	Other comprehensive income before reclassifications	0.3			—			(95.9		)	(95.6		)
	Amounts reclassified from accumulated other comprehensive income (loss)	—			4.5			—			4.5
	Other comprehensive income	0.3			4.5			(95.9		)	(91.1		)
	Balance September 30	$	(1.7	)	$	(85.3	)	$	(133.6	)	$	(220.6	)
	Reclassifications from accumulated other comprehensive income (loss) for the nine months ended September 30, 2013 were (in millions):
	Amortization of defined benefit pension and postemployment plans:
	Prior service cost	$	4.2
	Actuarial (gains) losses	3.4
	Net periodic benefit cost (see Note 9)	7.6
	Income tax expense	3.1
	Net of tax	$	4.5

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	We have evaluated events subsequent to the balance sheet date and determined there have not been any other events that have occurred that would require adjustment to or disclosure in our unaudited condensed consolidated financial statements.

Net_Income_Per_Common_Share_Ta

Net Income Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2013
Net Income per Common Share [Abstract]
Computations of Basic and Diluted Net Income per Common Share - Omnicom Group Inc.	The computation of basic and diluted net income per common share for the three and nine months ended September 30, 2013 and 2012 is (in millions, except per share amounts):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Net Income Available for Common Shares:
	Net income - Omnicom Group Inc.	$	196		$	203.9		$	690.7		$	691.2
	Net income allocated to participating securities	(4.8		)	(4.5		)	(18.1		)	(15.4		)
		$	191.2		$	199.4		$	672.6		$	675.8
	Weighted Average Shares:
	Basic	258.2			266.6			259			269.6
	Dilutive stock options and restricted shares and shares issuable for the conversion value of convertible debt	1.7			1.9			1.4			1.9
	Diluted	259.9			268.5			260.4			271.5
	Anti-dilutive stock options and restricted shares	—			0.2			0.1			0.2
	Net Income per Common Share - Omnicom Group Inc.:
	Basic	$	0.74		$	0.75		$	2.6		$	2.51
	Diluted	$	0.74		$	0.74		$	2.58		$	2.49

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and intangible assets at September 30, 2013 and December 31, 2012 were (in millions):
		2013								2012
		Gross			Accumulated			Net		Gross		Accumulated		Net
		Carrying			Amortization			Carrying		Carrying		Amortization		Carrying
		Value						Value		Value				Value
	Goodwill	$	9,450.60		$	581.6		$	8,869.00	$	9,424.30	$	580.1	$	8,844.20
	Intangible assets:
	Purchased and internally developed software	$	285.3		$	226.7		$	58.6	$	283.3	$	218.8	$	64.5
	Customer related and other	665.7			326.2			339.5		670.8		279.2		391.6
		$	951		$	552.9		$	398.1	$	954.1	$	498	$	456.1
Changes in Goodwill	Change in goodwill for the nine months ended September 30, 2013 and 2012 were (in millions):
		2013			2012
	Balance January 1	$	8,844.20		$	8,456.30
	Acquisitions	55.5			225.6
	Dispositions	(8.5		)	(2.5		)
	Foreign currency translation	(22.2		)	49.2
	Balance September 30	$	8,869.00		$	8,728.60

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Available and Unused Lines of Credit	Our available and unused lines of credit at September 30, 2013 and December 31, 2012 were (in millions):
		2013		2012
	Credit Agreement	$	2,500.00	$	2,500.00
	Uncommitted lines of credit	1,083.40		878.2
	Available and unused lines of credit	$	3,583.40	$	3,378.20
Long-Term Notes Payable [Member]
Long-Term Debt	Long-term notes payable at September 30, 2013 and December 31, 2012 were (in millions):
		2013		2012
	5.90% Senior Notes due April 15, 2016	$	1,000.00	$	1,000.00
	6.25% Senior Notes due July 15, 2019	500		500
	4.45% Senior Notes due August 15, 2020	1,000.00		1,000.00
	3.625% Senior Notes due May 1, 2022	1,250.00		1,250.00
	Other notes and loans	0.3		0.4
		3,750.30		3,750.40
	Unamortized premium (discount) on Senior Notes, net	15		16
	Deferred gain from termination of interest rate swaps on Senior Notes due 2016	17.7		23.1
		3,783.00		3,789.50
	Less current portion	0.3		0.4
	Long-term notes payable	$	3,782.70	$	3,789.10
Convertible Debt [Member]
Long-Term Debt	Convertible debt at September 30, 2013 and December 31, 2012 was (in millions):
		2013		2012
	Convertible Notes due July 31, 2032	$	252.7	$	252.7
	Convertible Notes due June 15, 2033	—		0.1
	Convertible Notes due July 1, 2038	—		406.6
		252.7		659.4
	Less current portion	—		—
	Convertible debt	$	252.7	$	659.4

Segment_Reporting_Tables

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]
Revenue and Long-Lived Assets and Goodwill by Geographic Area	Revenue and long-lived assets and goodwill by geographic area as of and for the periods ended September 30, 2013 and 2012 were (in millions):
		Americas		EMEA		Asia Pacific
	2013
	Revenue - Three months ended	$	2,054.40	$	1,050.80	$	385.3
	Revenue - Nine months ended	6,252.30		3,138.50		1,135.60
	Long-lived assets and goodwill	6,072.40		2,906.10		592.1
	2012
	Revenue - Three months ended	$	2,003.10	$	1,007.20	$	396.3
	Revenue - Nine months ended	6,073.80		3,072.80		1,128.20
	Long-lived assets and goodwill	6,088.50		2,738.10		602

Pension_and_Other_Postemployme1

Pension and Other Postemployment Benefits (Tables)	9 Months Ended
	Sep. 30, 2013
Defined Benefit Pension Plans [Member]
Components of Net Periodic Benefit Cost	Defined Benefit Pension Plans
	The components of net periodic benefit cost for the nine months ended September 30, 2013 and 2012 were (in millions):
		2013			2012
	Service cost	$	3.3		$	4.6
	Interest cost	4.6			4.6
	Expected return on plan assets	(2.1		)	(1.9		)
	Amortization of prior service cost	2.7			2.4
	Amortization of actuarial (gains) losses	2.4			1.1
		$	10.9		$	10.8
Postemployment Arrangements [Member]
Components of Net Periodic Benefit Cost	Postemployment Arrangements
	The components of net periodic benefit cost for the nine months ended September 30, 2013 and 2012 were (in millions):
		2013			2012
	Service cost	$	3		$	3
	Interest cost	3.3			3.5
	Amortization of prior service cost	1.5			1.5
	Amortization of actuarial (gains) losses	1			0.6
		$	8.8		$	8.6

Operating_Expenses_Tables

Operating Expenses (Tables)	9 Months Ended
	Sep. 30, 2013
Operating Expenses [Abstract]
Components of Operating Expenses	Operating expenses for the three and nine months ended September 30, 2013 and 2012 were (in millions):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2013		2012		2013		2012
	Salary and service costs	$	2,579.20	$	2,515.80	$	7,711.50	$	7,491.50
	Office and general expenses	503.8		503.5		1,512.60		1,527.10
	Merger expenses	28.1		—		28.1		—
	Operating expenses	$	3,111.10	$	3,019.30	$	9,252.20	$	9,018.60
	In the third quarter of 2013 we incurred $28.1 million of expenses in connection with the pending merger with Publicis, which were primarily comprised of professional fees. The merger expenses are shown as a separate component of operating expenses. We expect to incur significant additional merger expenses.

Supplemental_Cash_Flow_Tables

Supplemental Cash Flow (Tables)	9 Months Ended
	Sep. 30, 2013
Supplemental Cash Flow [Abstract]
Changes in Operating Capital	Change in operating capital for the nine months ended September 30, 2013 and 2012 were (in millions):
		2013			2012
	(Increase) decrease in accounts receivable	$	294		$	438.1
	(Increase) decrease in work in process and other current assets	(392.8		)	(205.6		)
	Increase (decrease) in accounts payable	(668.9		)	(697.4		)
	Increase (decrease) in customer advances and other current liabilities	97.6			(314.5		)
	Change in other assets and liabilities, net	15.9			113.5
		$	(654.2	)	$	(665.9	)
	Income taxes paid	$	335.2		$	287.5
	Interest paid	$	134.8		$	114.8

Fair_Value_Tables

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value [Abstract]
Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	Financial assets and liabilities measured at fair value on a recurring basis at September 30, 2013 and December 31, 2012 were (in millions):
	September 30, 2013	Level 1		Level 2		Level 3		Total
	Assets:
	Cash and cash equivalents	$	1,521.50					$	1,521.50
	Short-term investments	12.9						12.9
	Available-for-sale securities	4.6						4.6
	Forward foreign exchange contracts			$	1.3			1.3
	Liabilities:
	Forward foreign exchange contracts			$	0.3			$	0.3
	Contingent interest derivative			2.8				2.8
	Contingent purchase price obligations					$	213.3	213.3
	December 31, 2012	Level 1		Level 2		Level 3		Total
	Assets:
	Cash and cash equivalents	$	2,678.30					$	2,678.30
	Short-term investments	20.6						20.6
	Available-for-sale securities	3.9						3.9
	Forward foreign exchange contracts			$	0.5			0.5
	Liabilities:
	Contingent purchase price obligations					$	266.2	$	266.2
Carrying Amounts and Fair Value of Financial Instruments	The carrying amount and fair value of our financial instruments at September 30, 2013 and December 31, 2012 were (in millions):
		2013				2012
		Carrying		Fair		Carrying		Fair
		Amount		Value		Amount		Value
	Assets:
	Cash and cash equivalents	$	1,521.50	$	1,521.50	$	2,678.30	$	2,678.30
	Short-term investments	12.9		12.9		20.6		20.6
	Forward foreign exchange contracts	1.3		1.3		0.5		0.5
	Available-for-sale securities	4.6		4.6		3.9		3.9
	Cost method investments	21.7		21.7		23.1		23.1
	Liabilities:
	Short-term borrowings	$	18.3	$	18.3	$	6.4	$	6.4
	Forward foreign exchange contracts	0.3		0.3		—		—
	Contingent interest derivative	2.8		2.8		—		—
	Contingent purchase price obligations	213.3		213.3		266.2		266.2
	Debt	4,035.70		4,250.70		4,448.90		4,857.30

Changes_in_Accumulated_Other_C1

Changes in Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2013
Changes in Accumulated Other Comprehensive Income (Loss) [Abstract]
Changes in accumulated other comprehensive income (loss)	The changes in accumulated other comprehensive income (loss) for the nine months ended September 30, 2013 were (in millions):
		Unrealized Gain and (Loss) on Available-for-Sale Securities			Defined Benefit Pension and Postemployment Plans			Foreign Currency Translation			Total
	Balance January 1	$	(2.0	)	$	(89.8	)	$	(37.7	)	$	(129.5	)
	Other comprehensive income before reclassifications	0.3			—			(95.9		)	(95.6		)
	Amounts reclassified from accumulated other comprehensive income (loss)	—			4.5			—			4.5
	Other comprehensive income	0.3			4.5			(95.9		)	(91.1		)
	Balance September 30	$	(1.7	)	$	(85.3	)	$	(133.6	)	$	(220.6	)
Reclassifications from accumulated other comprehensive income (loss)	Reclassifications from accumulated other comprehensive income (loss) for the nine months ended September 30, 2013 were (in millions):
	Amortization of defined benefit pension and postemployment plans:
	Prior service cost	$	4.2
	Actuarial (gains) losses	3.4
	Net periodic benefit cost (see Note 9)	7.6
	Income tax expense	3.1
	Net of tax	$	4.5

Business_Combination_Agreement1

Business Combination Agreement (Details)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
		Publicis Merger [Member]	Omnicom Merger [Member]
		EUR (€)	USD ($)
Date of Business Combination Agreement	27-Jul-13
Number of Shares of Combined Entity to be Exchanged Per Share of Merging Entity		1	0.813008
Business Combination Agreement, Transaction Dividend to be Declared		€ 1	$2
Business Combination Agreement, Maximum Dividends to be Excluded from Equalization			$0.80

Net_Income_Per_Common_Share_De

Net Income Per Common Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Income Available for Common Shares:
Net income - Omnicom Group Inc.	$196	$203.90	$690.70	$691.20
Net income allocated to participating securities	-4.8	-4.5	-18.1	-15.4
Net income available for common shares	$191.20	$199.40	$672.60	$675.80
Weighted Average Shares:
Basic	258.2	266.6	259	269.6
Dilutive stock options and restricted shares and shares issuable for the conversion value of convertible debt	1.7	1.9	1.4	1.9
Diluted	259.9	268.5	260.4	271.5
Anti-dilutive stock options and restricted shares	0	0.2	0.1	0.2
Net Income per Common Share - Omnicom Group Inc.:
Basic	$0.74	$0.75	$2.60	$2.51
Diluted	$0.74	$0.74	$2.58	$2.49

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Goodwill, Gross Carrying Value	$9,450.60		$9,424.30
Goodwill, Accumulated Amortization	581.6		580.1
Goodwill, Net Carrying Value	8,869	8,728.60
Intangible assets:, Gross Carrying Value	951		954.1
Intangible assets:, Accumulated Amortization	552.9		498
Intangible assets:, Net Carrying Value	398.1		456.1
Goodwill [Roll Forward]
Goodwill, Balance January 1	8,844.20	8,456.30
Goodwill, Acquisitions	55.5	225.6
Goodwill, Dispositions	-8.5	-2.5
Goodwill, Foreign currency translation	-22.2	49.2
Goodwill, Balance September 30	8,869	8,728.60
Goodwill, impairment losses	0
Goodwill, accumulated impairment losses	0
Goodwill, acquisitions of noncontrolling interests	9.2	16.2
Purchased and internally developed software
Intangible assets:, Gross Carrying Value	285.3		283.3
Intangible assets:, Accumulated Amortization	226.7		218.8
Intangible assets:, Net Carrying Value	58.6		64.5
Customer related and other
Intangible assets:, Gross Carrying Value	665.7		670.8
Intangible assets:, Accumulated Amortization	326.2		279.2
Intangible assets:, Net Carrying Value	$339.50		$391.60

Debt_Details

Debt (Details) (USD $)

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

Jun. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 24, 2013

Sep. 23, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Jun. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Credit Agreement expiring October 2016 [Member]

Credit Agreement expiring October 2016 [Member]

Credit Agreement expiring October 2016 [Member]

Uncommitted lines of credit [Member]

Uncommitted lines of credit [Member]

5.90% Senior Notes due April 15, 2016

5.90% Senior Notes due April 15, 2016

6.25% Senior Notes due July 15, 2019

6.25% Senior Notes due July 15, 2019

4.45% Senior Notes due August 15, 2020

4.45% Senior Notes due August 15, 2020

3.625% Senior Notes due May 1, 2022

3.625% Senior Notes due May 1, 2022

Other notes and loans

Other notes and loans

Convertible Notes due July 31, 2032

Convertible Notes due July 31, 2032

Convertible Notes due July 31, 2032

Convertible Notes due July 31, 2032

Convertible Notes due July 31, 2032

2033 Notes and 2038 Notes [Member]

Convertible Notes due June 15, 2033

Convertible Notes due June 15, 2033

Convertible Notes due July 1, 2038

Convertible Notes due July 1, 2038

Commercial Paper [Member]

Rate

Rate

Rate

Lines of Credit [Abstract]

Credit Agreement, maximum borrowing capacity

$2,500,000,000

$1,500,000,000

Credit Agreement, expiration date

12-Oct-16

Available and unused lines of credit

3,583,400,000

3,378,200,000

2,500,000,000

2,500,000,000

1,083,400,000

878,200,000

Credit Agreement, covenant terms

The Credit Agreement contains financial covenants that restrict our ability to incur indebtedness as defined in the agreement. These financial covenants limit the Leverage Ratio of total consolidated indebtedness to total consolidated EBITDA to no more than 3 times for the most recently ended 12 month period (under the Credit Agreement, EBITDA is defined as earnings before interest, taxes, depreciation and amortization). We are also required to maintain a minimum Interest Coverage Ratio of consolidated EBITDA to interest expense of at least 5 times for the most recently ended 12 month period.

Credit Agreement, covenant compliance

At September 30, 2013 we were in compliance with these covenants, as our Leverage Ratio was 1.9 times and our Interest Coverage Ratio was 10.6 times.

Short-Term Borrowings [Abstract]

Short-term borrowings

18,300,000

6,400,000

Long-Term Notes Payable [Abstract]

Long-term notes payable, carrying amount

3,750,300,000

3,750,400,000

1,000,000,000

1,000,000,000

500,000,000

500,000,000

1,000,000,000

1,000,000,000

1,250,000,000

1,250,000,000

300,000

400,000

Unamortized premium (discount) on Senior Notes, net

15,000,000

16,000,000

Deferred gain from termination of interest rate swaps on Senior Notes due 2016

17,700,000

23,100,000

Long-term notes payable, total

3,783,000,000

3,789,500,000

Long-term notes payable, current portion

300,000

400,000

Long-Term Notes Payable

3,782,700,000

3,789,100,000

Convertible Debt [Abstract]

Convertible debt, total

252,700,000

659,400,000

252,700,000

252,700,000

252,700,000

0

100,000

0

406,600,000

Convertible debt, current

0

0

Convertible Debt

252,700,000

659,400,000

Long-Term Notes Payable and Convertible Debt [Abstract]

Interest rate

5.90%

6.25%

4.45%

3.63%

0.00%

0.00%

Maturity date

15-Apr-16

15-Jul-19

15-Aug-20

1-May-22

31-Jul-32

Convertible Debt, Call Date

16-May-13

Convertible Debt, Percentage of Principal Amount Redeemed

100.00%

Convertible Debt, Conversion Rate

18.18

18.249

19.4174

Convertible Debt, Latest Conversion Date

13-Jun-13

Convertible Debt, Principle Amount Settled in Cash

406,100,000

Convertible Debt, Shares Issued for Conversion Premium

1,499,792

1,499,792

Convertible Debt, Repurchase Date

17-Jun-13

Convertible Debt, Repurchase Amount

600,000

Long-term Debt, Contingent Payment of Principal or Interest

Beginning August 1, 2013, our Convertible Notes due July 31, 2032 ("2032 Notes") will accrue contingent interest for the six-month period August 1, 2013 to January 31, 2014. Contingent interest of $2.81 per $1,000 principal amount is payable quarterly on October 31, 2013 and January 31, 2014.

Convertible Debt, Contingent Interest Derivative, Interest Expense

$2,800,000

Segment_Reporting_Details

Segment Reporting (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue	$3,490.50	$3,406.60	$10,526.40	$10,274.80
Americas
Revenue	2,054.40	2,003.10	6,252.30	6,073.80
Long-lived assets and goodwill	6,072.40	6,088.50	6,072.40	6,088.50
EMEA
Revenue	1,050.80	1,007.20	3,138.50	3,072.80
Long-lived assets and goodwill	2,906.10	2,738.10	2,906.10	2,738.10
Asia Pacific
Revenue	385.3	396.3	1,135.60	1,128.20
Long-lived assets and goodwill	$592.10	$602	$592.10	$602

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
Effective income tax rate			33.80%	33.80%
Current Taxes Payable, Conversion of Debt		$52.70
Adjustment to Additional Paid-In Capital, Conversion of Debt		34.5
Taxes Paid, Conversion of Debt	40
Unrecognized tax benefits	141.5		141.5
Unrecognized tax benefits that would impact effective tax rate	$62.80		$62.80

Pension_and_Other_Postemployme2

Pension and Other Postemployment Benefits (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Defined Benefit Pension Plans [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service cost	$3.30	$4.60
Interest cost	4.6	4.6
Expected return on plan assets	-2.1	-1.9
Amortization of prior service cost	2.7	2.4
Amortization of actuarial (gains) losses	2.4	1.1
Net periodic benefit cost	10.9	10.8
Defined benefit pension plans, contributions by employer	3.1	5.3
Postemployment Arrangements [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service cost	3	3
Interest cost	3.3	3.5
Amortization of prior service cost	1.5	1.5
Amortization of actuarial (gains) losses	1	0.6
Net periodic benefit cost	$8.80	$8.60

Operating_Expenses_Details

Operating Expenses (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Salary and service costs	$2,579.20	$2,515.80	$7,711.50	$7,491.50
Office and general expenses	503.8	503.5	1,512.60	1,527.10
Merger expenses	28.1	0	28.1	0
Operating expenses	$3,111.10	$3,019.30	$9,252.20	$9,018.60

Supplemental_Cash_Flow_Details

Supplemental Cash Flow (Details) (USD $)	3 Months Ended	9 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
Changes in Operating Capital [Abstract]
(Increase) decrease in accounts receivable		$294	$438.10
(Increase) decrease in work in process and other current assets		-392.8	-205.6
Increase (decrease) in accounts payable		-668.9	-697.4
Increase (decrease) in customer advances and other current liabilities		97.6	-314.5
Change in other assets and liabilities, net		15.9	113.5
Change in operating capital		654.2	665.9
Income taxes paid		335.2	287.5
Interest paid		134.8	114.8
Convertible Debt, Shares Issued for Conversion Premium	1,499,792
Convertible Debt, Fair Value of Common Stock Issued	95.4
Adjustment to Additional Paid-In Capital, Conversion of Convertible Debt	$34.50

Fair_Value_Details

Fair Value (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013
In Millions, unless otherwise specified			Carrying Amount	Carrying Amount	Fair Value	Fair Value	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Contingent Purchase Price Obligations [Member]
							Level 1	Level 1	Level 2	Level 2	Level 3	Level 3	Total	Total
Assets:
Cash and cash equivalents			$1,521.50	$2,678.30	$1,521.50	$2,678.30	$1,521.50	$2,678.30					$1,521.50	$2,678.30
Short-term investments	12.9	20.6	12.9	20.6	12.9	20.6	12.9	20.6					12.9	20.6
Forward foreign exchange contracts			1.3	0.5	1.3	0.5			1.3	0.5			1.3	0.5
Available-for-sale securities			4.6	3.9	4.6	3.9	4.6	3.9					4.6	3.9
Cost method investments			21.7	23.1	21.7	23.1
Liabilities:
Short-term borrowings			18.3	6.4	18.3	6.4
Forward foreign exchange contracts			0.3	0	0.3	0			0.3				0.3
Contingent interest derivative			2.8	0	2.8	0			2.8				2.8
Contingent purchase price obligations			213.3	266.2	213.3	266.2					213.3	266.2	213.3	266.2
Debt			4,035.70	4,448.90	4,250.70	4,857.30
Changes in contingent purchase price obligations, payments															$68.90

Changes_in_Accumulated_Other_C2

Changes in Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance January 1			($129.50)
Other comprehensive income before reclassifications			-95.6
Amounts reclassified from accumulated other comprehensive income (loss)			4.5
Other comprehensive income			-91.1
Balance September 30	-220.6		-220.6
Reclassification out of Accumulated Other Comprehensive Income [Abstract]
Income Before Income Taxes and Income From Equity Method Investments	336.6	347	1,149.60	1,151.90
Income Tax Expense	116.2	118.7	388.9	389.9
Net Income	224.7	233.6	771.2	773.9
Unrealized Gain and (Loss) on Available-for-Sale Securities
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance January 1			-2
Other comprehensive income before reclassifications			0.3
Amounts reclassified from accumulated other comprehensive income (loss)			0
Other comprehensive income			0.3
Balance September 30	-1.7		-1.7
Defined Benefit Pension and Postemployment Plans
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance January 1			-89.8
Other comprehensive income before reclassifications			0
Amounts reclassified from accumulated other comprehensive income (loss)			4.5
Other comprehensive income			4.5
Balance September 30	-85.3		-85.3
Defined Benefit Pension and Postemployment Plans | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Abstract]
Prior service cost			4.2
Actuarial (gains) losses			3.4
Income Before Income Taxes and Income From Equity Method Investments			7.6
Income Tax Expense			3.1
Net Income			4.5
Foreign Currency Translation
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance January 1			-37.7
Other comprehensive income before reclassifications			-95.9
Amounts reclassified from accumulated other comprehensive income (loss)			0
Other comprehensive income			-95.9
Balance September 30	($133.60)		($133.60)