Restructuring Charges (Accrual Rollfoward) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring Reserve [Roll Forward]
Restructuring accruals - January 1				$ 3	$ 12
Restructuring charges		$ 6	$ 1	18	5
Cash payments				(11)	(11)
Foreign currency and other				(1)	(1)
Restructuring accruals - September 30		9	5	9	5
Water Infrastructure
Restructuring Reserve [Roll Forward]
Restructuring charges		5	1	12	5
Restructuring accruals - September 30		4	2	4	2
Applied Water
Restructuring Reserve [Roll Forward]
Restructuring charges		1	0	4	0
Restructuring accruals - September 30		0	0	0	0
Regional Selling Locations
Restructuring Reserve [Roll Forward]
Restructuring accruals - September 30	[1]	3	3	3	3
Corporate Segment
Restructuring Reserve [Roll Forward]
Restructuring charges		0	0	2	0
Restructuring accruals - September 30		$ 2	$ 0	$ 2	$ 0

[1] (a)Regional selling locations consist primarily of selling and marketing organizations that incurred restructuring expense which was allocated to the segments. The liabilities associated with restructuring expense were not allocated to the segments.