Acquisitions (Allocation Of Acquisition Costs) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Cash	$ 640	$ 90
Estimated fair value of deferred/contingent consideration	94	29
Total Consideration	734	119
Allocation of purchase price:
Goodwill	9,100	$ 7,975	$ 8,369	$ 7,889
Current Fiscal Period Acquisitions
Business Acquisition [Line Items]
Cash	640
Estimated fair value of deferred/contingent consideration	94
Total Consideration	734
Allocation of purchase price:
Cash and cash equivalents	11
Accounts receivable, net	17
Property, plant, and equipment	7
Other intangible assets	293
Goodwill	533
Other assets	2
Total assets acquired	863
Current liabilities	21
Other liabilities	108
Total liabilities assumed	129
Net assets acquired	$ 734