Restructuring and Asset Impairment Charges - Estimated Restructuring Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	$ 73
Incurred restructuring costs	53
Expected costs remaining	20
2016 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	51
Incurred restructuring costs	1	$ 50
Expected costs remaining	0
Corporate | 2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	2
Incurred restructuring costs	0
Expected costs remaining	2
Corporate | 2016 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	0
Incurred restructuring costs	0	0
Expected costs remaining	0
Operating Segments | Water Infrastructure | 2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	26
Incurred restructuring costs	19
Expected costs remaining	7
Operating Segments | Water Infrastructure | 2016 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	19
Incurred restructuring costs	1	18
Expected costs remaining	0
Operating Segments | Applied Water | 2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	11
Incurred restructuring costs	4
Expected costs remaining	7
Operating Segments | Applied Water | 2016 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	5
Incurred restructuring costs	0	5
Expected costs remaining	0
Operating Segments | Measurement & Control Solutions | 2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	34
Incurred restructuring costs	30
Expected costs remaining	4
Operating Segments | Measurement & Control Solutions | 2016 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	27
Incurred restructuring costs	0	$ 27
Expected costs remaining	$ 0