Weighted-average period of amortization for finite-lived intangible asset acquired in business combination, asset acquisition, and from joint venture formation, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Excludes goodwill and capitalized cost for software to be sold, leased, or marketed.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 985
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481283/985-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-1

Acquisitions and Divestitures (Details) $ in Millions									3 Months Ended			9 Months Ended
Acquisitions and Divestitures (Details) $ in Millions	Sep. 02, 2026 USD ($)	Aug. 10, 2026 USD ($)	May 26, 2026 USD ($)	Dec. 02, 2025 USD ($)	Jul. 23, 2025 USD ($)	Apr. 01, 2025 USD ($)	Feb. 07, 2025 USD ($)	Jan. 31, 2025 USD ($) employee	Sep. 30, 2026 USD ($)	Mar. 31, 2026 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Dec. 31, 2025 USD ($)
Business Combination [Line Items]
Goodwill									$ 8,524			$ 8,524		$ 8,332
Acquisition of business, net of cash acquired												425	$ 113
Payments to acquire productive assets												268	248
Proceeds from sale of businesses, net of cash disposed												95	48
Loss from sale of businesses									5		$ 37	17	$ 47
Disposed of by Sale \| International Metering Business
Business Combination [Line Items]
Disposal Group, Including Discontinued Operation, Consideration			$ 73
Disposal Group, Including Discontinued Operation, Consideration Received, Net			68
Proceeds from sale of businesses, net of cash disposed			63
Proceeds from sale of businesses, net of cash disposed			58
Disposal Group, Including Discontinued Operation, Consideration, Note Receivable			10
Loss from sale of businesses			$ 44						7	$ (23)		21
Disposed of by Sale \| Other Divestitures
Business Combination [Line Items]
Proceeds from sale of businesses, net of cash disposed									30			37
Loss from sale of businesses									(2)			(4)
Disposed of by Sale \| Evoqua Magneto
Business Combination [Line Items]
Proceeds from sale of businesses, net of cash disposed							$ 61
Proceeds from sale of businesses, net of cash disposed							$ 48
Loss from sale of businesses											$ 10	8
Disposal Group, Including Discontinued Operation, Working Capital Adjustment										$ 2
Vacom Systems LLC
Business Combination [Line Items]
Payments to acquire productive assets						$ 42
Payments for asset acquisition at closing						$ 37
Royalty on revenue, percentage						5.00%
Royalty on revenue, period after acquisition						5 years
Royalty on revenue, maximum						$ 25
Vacom Systems LLC \| Developed Technology Rights
Business Combination [Line Items]
Intangible Asset, Finite-Lived, Acquired						$ 49
Acquired finite-lived intangible asset, useful life						15 years
Cornell Pump and Roper Pump
Business Combination [Line Items]
Percentage of voting interests acquired		100.00%
Consideration transferred		$ 1,460
WaterFleet Intermediate Holdings, Inc.
Business Combination [Line Items]
Percentage of voting interests acquired	100.00%
Goodwill									$ 111			111
Intangible Asset, Finite-Lived, Acquired												$ 65
March 2026 Acquisition
Business Combination [Line Items]
Consideration transferred	$ 217
TriOS Mess-und Datentechnik GmbH
Business Combination [Line Items]
Percentage of voting interests acquired					100.00%
Goodwill				$ 155
Payments to Acquire Businesses, Gross				219
Acquisition of business, net of cash acquired				210
Payments to acquire business, gross, at closing				216
Payments to acquire business, net of cash acquired, at closing				207
Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill				55
Pac Machine
Business Combination [Line Items]
Percentage of voting interests acquired					100.00%
Goodwill				30
Payments to Acquire Businesses, Gross				66
Acquisition of business, net of cash acquired				62
Payments to acquire business, gross, at closing				54
Payments to acquire business, net of cash acquired, at closing				50
Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill				27
Business Combination, Consideration Transferred, Settlement Of Liability				3
Remaining consideration to be paid				$ 9
Business combination, remaining consideration to be paid, period				4 years
EMX Holdings, Inc.
Business Combination [Line Items]
Percentage of voting interests acquired					100.00%
Consideration transferred					$ 106
Goodwill					74
Payments to Acquire Businesses, Gross								$ 7
Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill					$ 34
Simply Clean Air and Water, Inc
Business Combination [Line Items]
Number of employees \| employee								20