Average stock price used to calculate common stock equivalents

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- Definition

Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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-Publisher FASB

-Name Accounting Standards Codification

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-Section 45

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-Subparagraph (SX 210.5-03.13)

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- Definition

Amount of income (loss) from continuing operations attributable to the noncontrolling interest. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items, and noncontrolling interest.

+ References

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- Definition

Number of options outstanding, including both vested and non-vested options.

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-Topic 718

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-Topic 718

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-Section 50

-Paragraph 2

-Subparagraph (c)(1)(i)-(ii)

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- Definition

The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

+ References

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- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

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- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Glossary Weighted-Average Number of Common Shares Outstanding

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Summary of Significant Accounting Policies (Basic and Diluted EPS Calculation for Continuing Operations) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Income from continuing operations	$ 269	$ 305	$ 440	$ 457	$ 307	$ 260	$ 400	$ 412	$ 1,471	$ 1,379	$ 1,204
Less: Net income attributable to non-controlling interests									32	28	25
Net income attributable to the Company									$ 1,439	$ 1,351	$ 1,179
Basic weighted average common shares outstanding (in shares)									545,000,000	549,000,000	544,000,000
Dilutive effect of potentially issuable common shares (in shares)									8,000,000	9,000,000	8,000,000
Dilutive weighted average common shares outstanding (in shares)									553,000,000	558,000,000	552,000,000
Average stock price used to calculate common stock equivalents (in dollars per share)									$ 51.15mmc_AverageSharePriceCommonStock	$ 40.97mmc_AverageSharePriceCommonStock	$ 33.10mmc_AverageSharePriceCommonStock
Stock options outstanding (in shares)	17,995,082				22,567,866				17,995,082	22,567,866	32,045,793