Restructuring and Asset Impairment Charges (Components of Restructuring Charges and Segment Allocation) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Severance and other charges		$ 51	$ 19	$ 20
Lease related charges		1	1	0
Other restructuring charges		2	1	2
Reversal of restructuring accruals		(1)	(1)	(2)
Total restructuring charges		53	20	20
Asset impairment charges		10	2	5
Total restructuring and asset impairment charges		63	22	25
Restructuring and asset impairment charges		63	22	25
Water Infrastructure
Restructuring Cost and Reserve [Line Items]
Asset impairment charges	$ 2
Restructuring and asset impairment charges		20	11	7
Applied Water
Restructuring Cost and Reserve [Line Items]
Restructuring and asset impairment charges		5	2	13
Measurement & Control Solutions
Restructuring Cost and Reserve [Line Items]
Asset impairment charges		10
Restructuring and asset impairment charges		38	9	5
Corporate and other
Restructuring Cost and Reserve [Line Items]
Restructuring and asset impairment charges		$ 0	$ 0	$ 0

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Includes, but is not limited to, one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, and relocating employees, and termination benefits associated with an ongoing benefit arrangement. Excludes expenses associated with special or contractual termination benefits, a discontinued operation or an asset retirement obligation.

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Amount of expense (reversal of expense) which increases (decreases) the restructuring reserve from an adjustment to a previously accrued restructuring liability.

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Amount of restructuring charges, remediation cost, and asset impairment loss.

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Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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