Goodwill and Other Intangible Assets (Goodwill Rollforward) (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
Changes in the carrying value of goodwill by operating segment
Balance as of January 1, 2019	$ 2,976
Divested/Acquired	8
Foreign currency and other	4
Balance as of March 31, 2019	2,988
Water Infrastructure
Changes in the carrying value of goodwill by operating segment
Balance as of January 1, 2019	653
Divested/Acquired	0
Foreign currency and other	1
Balance as of March 31, 2019	654
Applied Water
Changes in the carrying value of goodwill by operating segment
Balance as of January 1, 2019	516
Divested/Acquired	0
Foreign currency and other	(1)
Balance as of March 31, 2019	515
Measurement & Control Solutions
Changes in the carrying value of goodwill by operating segment
Balance as of January 1, 2019	1,807
Divested/Acquired	8
Foreign currency and other	4
Balance as of March 31, 2019	$ 1,819

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Goodwill, Acquired (Divested) During Period

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