Segment Information (Summary of Operations by Segment) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Financial information for each reportable segment
Revenues		$ 1,123	$ 1,237
Operating income		61	109
Interest Expense		16	18
Other Nonoperating Income (Expense)		(3)	2
Gain from sale of business		0	1
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest		42	94
Depreciation and amortization		64	64
Capital expenditures		51	69
Water Infrastructure
Financial information for each reportable segment
Revenues		438	482
Operating income		39	51
Depreciation and amortization		15	15
Capital expenditures		10	30
Applied Water
Financial information for each reportable segment
Revenues		338	379
Operating income		47	56
Depreciation and amortization		6	6
Capital expenditures		9	6
Measurement & Control Solutions
Financial information for each reportable segment
Revenues		347	376
Operating income		(12)	16
Depreciation and amortization		36	36
Capital expenditures		27	24
Regional Selling Locations
Financial information for each reportable segment
Depreciation and amortization	[1]	4	4
Capital expenditures	[2]	4	4
Corporate and other
Financial information for each reportable segment
Operating income		(13)	(14)
Depreciation and amortization		3	3
Capital expenditures		$ 1	$ 5

[1] Depreciation and amortization expense incurred by the Regional selling locations was included in an overall allocation of Regional selling location costs to the segments; however, a certain portion of that expense was not specifically identified to a segment. That expense is captured in this Regional selling location line.

[2] Represents capital expenditures incurred by the Regional selling locations not allocated to the segments.