Business Acquisitions (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	$ 579	$ 13
Other acquisitions [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	$ 579

The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration