Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 1,231	$ 1,222	$ 3,690	$ 3,642
Lease Revenue	65	65	188	179
Total	1,296	1,287	3,878	3,821
Water Infrastructure
Disaggregation of Revenue [Line Items]
Total	531	541	1,574	1,567
Water Infrastructure | United States
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	141	139	434	387
Water Infrastructure | Europe
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	170	174	509	542
Water Infrastructure | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	92	91	260	252
Water Infrastructure | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	62	72	182	207
Water Infrastructure | Transport
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	369	380	1,111	1,114
Water Infrastructure | Treatment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	96	96	274	274
Applied Water
Disaggregation of Revenue [Line Items]
Total	376	378	1,149	1,132
Applied Water | United States
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	196	197	609	583
Applied Water | Europe
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	89	93	275	291
Applied Water | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	41	40	121	115
Applied Water | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	50	48	144	143
Applied Water | Building Services
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	207	208	636	608
Applied Water | Industrial Water
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	169	170	513	524
Measurement & Control Solutions
Disaggregation of Revenue [Line Items]
Total	389	368	1,155	1,122
Measurement & Control Solutions | United States
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	251	238	739	674
Measurement & Control Solutions | Europe
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	63	59	199	214
Measurement & Control Solutions | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	27	31	85	106
Measurement & Control Solutions | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	49	40	133	128
Measurement & Control Solutions | Water
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	193	168	587	514
Measurement & Control Solutions | Energy
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	90	90	248	254
Measurement & Control Solutions | Software as a Service/Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	26	26	75	96
Measurement & Control Solutions | Test
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 81	$ 84	$ 246	$ 258