XML 82 R60.htm IDEA: XBRL DOCUMENT v3.25.4

Regulatory Matters - Schedule of Infrastructure Surcharge (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Feb. 18, 2026	Dec. 31, 2025
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations		$ 69
Subsequent Event
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations	$ 16
New Jersey | November 29, 2025
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations		26
New Jersey | May 30, 2025
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations		15
Pennsylvania
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations		5
Pennsylvania | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations	11
Missouri
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations		17
Kentucky
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations		2
West Virginia
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations		$ 4
Illinois | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Total infrastructure surcharge authorizations	$ 5

X

- Definition

Public Utilities, Infrastructure Surcharge Authorizations

+ References

No definition available.

+ Details

Name:	awk_PublicUtilitiesInfrastructureSurchargeAuthorizations
Namespace Prefix:	awk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=stpr_NJ
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	awk_AuthorizationDateAxis=awk_November292025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	awk_AuthorizationDateAxis=awk_May302025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=stpr_PA
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=stpr_MO
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=stpr_KY
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=stpr_WV
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=stpr_IL
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: