Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 5,002	$ 4,963
Other									247	244
Total	$ 1,371	$ 1,296	$ 1,345	$ 1,237	$ 1,386	$ 1,287	$ 1,317	$ 1,217	5,249	5,207	$ 4,707
United States
Disaggregation of Revenue [Line Items]
Total									2,554	2,424	2,161
Europe
Disaggregation of Revenue [Line Items]
Total									1,380	1,449	1,335
Water Infrastructure
Disaggregation of Revenue [Line Items]
Total									2,177	2,176	2,004
Water Infrastructure | United States
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									593	539
Water Infrastructure | Europe
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									729	758
Water Infrastructure | Emerging Markets & Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									358	344
Water Infrastructure | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									250	291
Water Infrastructure | Transport
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									1,533	1,535
Water Infrastructure | Treatment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									397	397
Applied Water
Disaggregation of Revenue [Line Items]
Total									1,541	1,534	$ 1,421
Applied Water | United States
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									816	797
Applied Water | Europe
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									362	386
Applied Water | Emerging Markets & Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									164	153
Applied Water | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									199	198
Applied Water | Commercial Building Services
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									848	828
Applied Water | Industrial Water
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									693	706
Measurement & Control Solutions | United States
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									972	913
Measurement & Control Solutions | Europe
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									257	273
Measurement & Control Solutions | Emerging Markets & Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									118	144
Measurement & Control Solutions | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									184	167
Measurement & Control Solutions | Water
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									768	692
Measurement & Control Solutions | Electric
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									337	338
Measurement & Control Solutions | Software and Services/Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									99	123
Measurement & Control Solutions | Test
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 327	$ 344