Segment and Geographic Data (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financial information for each reportable segment
Revenue	$ 994	$ 902	$ 920	$ 837	$ 1,042	$ 963	$ 1,005	$ 906	$ 3,653	$ 3,916	$ 3,837
Operating income	$ 142	$ 120	$ 104	$ 83	$ 141	$ 130	$ 116	$ 76	449	463	363
Other non-operating income (expense), net									0	1	(10)
Gain from sale of business									9	11	0
Interest Expense									55	54	55
Income before taxes									403	421	298
Depreciation and amortization									133	142	150
Capital expenditures									117	119	126
Water Infrastructure
Financial information for each reportable segment
Revenue									2,231	2,442	2,384
Operating income									303	321	263
Depreciation and amortization									88	100	104
Capital expenditures									67	73	67
Applied Water
Financial information for each reportable segment
Revenue									1,422	1,474	1,453
Operating income									190	193	175
Depreciation and amortization									26	25	26
Capital expenditures									22	28	31
Regional Selling Locations
Financial information for each reportable segment
Depreciation and amortization									12	12	13
Capital expenditures									23	10	12
Corporate and other
Financial information for each reportable segment
Operating income									(44)	(51)	(75)
Depreciation and amortization									7	5	7
Capital expenditures									$ 5	$ 8	$ 16