XML 39 R27.htm IDEA: XBRL DOCUMENT v3.25.2

Nature of Operations and Basis of Consolidation (Details)	Dec. 31, 2024 customers
Number of customers	842,100

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- Definition

Number Of Customers

+ References

No definition available.

+ Details

Name:	nwe_NumberOfCustomers
Namespace Prefix:	nwe_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant