Segment and Geographic Data (Summary of Operating Results by Segment) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) Segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | Segment	3
Financial information for each reportable segment
Revenue	$ 5,195	$ 4,876	$ 5,249
Operating income	585	367	486
Other non-operating expense, net	0	(5)	(4)
Gain on sale of businesses	2	0	1
Interest Expense	76	77	67
Income before taxes	511	285	416
Depreciation and amortization	245	251	257
Capital expenditures	208	183	226
Water Infrastructure
Financial information for each reportable segment
Revenue	2,247	2,079	2,177
Operating income	387	318	365
Depreciation and amortization	51	57	61
Capital expenditures	74	48	79
Applied Water
Financial information for each reportable segment
Revenue	1,613	1,434	1,541
Operating income	240	205	241
Depreciation and amortization	22	24	24
Capital expenditures	22	18	19
Measurement & Control Solutions
Financial information for each reportable segment
Revenue	1,335	1,363	1,531
Operating income	12	(106)	(67)
Depreciation and amortization	145	142	144
Capital expenditures	79	90	100
Regional Selling Locations
Financial information for each reportable segment
Depreciation and amortization	20	20	18
Capital expenditures	25	22	19
Corporate and other
Financial information for each reportable segment
Operating income	(54)	(50)	(53)
Depreciation and amortization	7	8	10
Capital expenditures	$ 8	$ 5	$ 9