Restructuring Charges - Estimated Restructuring Costs (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Restructuring Cost and Reserve [Line Items]
Total expected costs	$ 11	$ 144
Total expected costs remaining	5	16
Costs Incurred In 2025
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period		93
Costs Incurred In Q1 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	0	31
Costs Incurred In Q2 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	6	4
Operating Segments \| Water Infrastructure
Restructuring Cost and Reserve [Line Items]
Total expected costs	0	87
Total expected costs remaining	0	4
Operating Segments \| Water Infrastructure \| Costs Incurred In 2025
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period		55
Operating Segments \| Water Infrastructure \| Costs Incurred In Q1 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	0	26
Operating Segments \| Water Infrastructure \| Costs Incurred In Q2 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	0	2
Operating Segments \| Applied Water
Restructuring Cost and Reserve [Line Items]
Total expected costs	7	26
Total expected costs remaining	5	1
Operating Segments \| Applied Water \| Costs Incurred In 2025
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period		23
Operating Segments \| Applied Water \| Costs Incurred In Q1 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	0	1
Operating Segments \| Applied Water \| Costs Incurred In Q2 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	2	1
Operating Segments \| Measurement and Control Solutions
Restructuring Cost and Reserve [Line Items]
Total expected costs	1	20
Total expected costs remaining	0	7
Operating Segments \| Measurement and Control Solutions \| Costs Incurred In 2025
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period		9
Operating Segments \| Measurement and Control Solutions \| Costs Incurred In Q1 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	0	3
Operating Segments \| Measurement and Control Solutions \| Costs Incurred In Q2 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	1	1
Operating Segments \| Water Solutions and Services
Restructuring Cost and Reserve [Line Items]
Total expected costs	3	11
Total expected costs remaining	0	4
Operating Segments \| Water Solutions and Services \| Costs Incurred In 2025
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period		6
Operating Segments \| Water Solutions and Services \| Costs Incurred In Q1 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	0	1
Operating Segments \| Water Solutions and Services \| Costs Incurred In Q2 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	3	0
Corporate and other
Restructuring Cost and Reserve [Line Items]
Total expected costs	0	0
Total expected costs remaining	0	0
Corporate and other \| Costs Incurred In 2025
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period		0
Corporate and other \| Costs Incurred In Q1 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	0	0
Corporate and other \| Costs Incurred In Q2 2026
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred during period	$ 0	$ 0