Business Combinations Business Combinations	3 Months Ended
Business Combinations Business Combinations	Mar. 31, 2021
Business Combinations [Abstract]
Business Combination Disclosure	BUSINESS COMBINATIONS 2021 Business Combinations During the three months ended March 31, 2021, NWN Water completed one acquisition of a water system that qualified as a business combination. The aggregate fair value of the preliminary consideration transferred for this acquisition was not material and is not significant to NW Holdings' results of operations. 2020 Business Combinations During 2020, NWN Water and its subsidiaries completed two significant acquisitions qualifying as business combinations. The aggregate fair value of the total cash consideration transferred for these acquisitions was $38.1 million, most of which was allocated to property, plant and equipment and goodwill. These transactions align with NW Holdings' water sector strategy as it continues to expand its water services territories in the Pacific Northwest and beyond and included: •Suncadia Water Company, LLC and Suncadia Environmental Company, LLC which were acquired by NWN Water of Washington on January 31, 2020, and •T&W Water Service Company which was acquired by NWN Water of Texas on March 2, 2020. As each of these acquisitions met the criteria of a business combination, a preliminary allocation of the consideration to the acquired net assets based on their estimated fair value as of the acquisition date was performed. In accordance with U.S. GAAP, the fair value determination involves management judgment in determining the significant estimates and assumptions used and was made using existing regulatory conditions for net assets associated with Suncadia Water Company, LLC and T&W Water Service Company. Final goodwill of $18.2 million was recognized from the acquisitions described above. No intangible assets aside from goodwill were acquired. The goodwill recognized is attributable to the regulated water utility service territories, experienced workforces, and the strategic benefits from both the water and wastewater utilities expected from growth in their service territories. The total amount of goodwill that is expected to be deductible for income tax purposes is approximately $16.5 million. The acquisition costs associated with each business combination were expensed as incurred. The results of these business combinations were not material to the consolidated financial results of NW Holdings. Other Business Combinations During 2020, NWN Water completed three additional acquisitions, comprised of four water systems and one wastewater system, which qualified as business combinations. The aggregate fair value of the preliminary consideration transferred for these acquisitions was approximately $1.5 million. These business combinations were not significant to NW Holdings' results of operations. Goodwill NW Holdings allocates goodwill to reporting units based on the expected benefit from the business combination. We perform an annual impairment assessment of goodwill at the reporting unit level, or more frequently if events and circumstances indicate that goodwill might be impaired. An impairment loss is recognized if the carrying value of a reporting unit’s goodwill exceeds its fair value. As a result of all acquisitions completed, total goodwill was $69.3 million as of March 31, 2021 and $69.2 million as of March 31, 2020 and December 31, 2020. The goodwill balance remained flat due to insignificant additions associated with our acquisitions in the water sector. All of our goodwill is related to water and wastewater acquisitions and is included in the other category for segment reporting purposes. The annual impairment assessment of goodwill occurs in the fourth quarter of each year. There have been no impairments recognized to date.