Acquisitions and Dispositions of Businesses - Acquisitions Narrative (Details) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($) acquisition	Dec. 31, 2017 acquisition
Business Acquisition
Number of business acquired under business combination \| acquisition	8	17
Weighted average useful life	7 years
2018 Acquisitions
Business Acquisition
Revenues from acquisitions included in the Company's Consolidated Statement of Income	$ 17
Other general expenses \| 2018 Acquisitions
Business Acquisition
Acquisition related costs	$ 2

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
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- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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- Definition

The number of businesses acquired by the entity during the period.

+ References

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