The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Goodwill and Other Intangible Assets (Details Textual) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Other Intangible Assets (Textual) [Abstract]
Goodwill arising from acquisition		$ 2,976	$ 2,768	$ 2,632
Impairment of the indefinite-lived intangibles		0	0
Amortization expense related to finite-lived intangible assets		$ 144	125	64
Impairment charge	$ 4
Customer and Distributor Relationships
Goodwill and Other Intangible Assets (Textual) [Abstract]
Finite-Lived Intangible Asset, Useful Life		14 years
Internally Developed Network Software
Goodwill and Other Intangible Assets (Textual) [Abstract]
Finite-Lived Intangible Asset, Useful Life		5 years
Proprietary Technology
Goodwill and Other Intangible Assets (Textual) [Abstract]
Finite-Lived Intangible Asset, Useful Life		14 years
Trademarks
Goodwill and Other Intangible Assets (Textual) [Abstract]
Finite-Lived Intangible Asset, Useful Life		13 years
Other
Goodwill and Other Intangible Assets (Textual) [Abstract]
Finite-Lived Intangible Asset, Useful Life		5 years
Water Infrastructure
Goodwill and Other Intangible Assets (Textual) [Abstract]
Goodwill arising from acquisition		$ 653	$ 667	$ 640