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Regulatory Rate Filings (Details) residence in Thousands |  |  |  |  |  |  |  |  |  | 3 Months Ended |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jul. 28, 2021 USD ($) | Mar. 01, 2021 USD ($) | Feb. 25, 2021 USD ($) | Jan. 29, 2021 USD ($) | Jan. 15, 2021 USD ($) | Dec. 01, 2020 USD ($) | Nov. 23, 2020 USD ($) | Oct. 28, 2020 USD ($) | Jun. 17, 2020 USD ($) | Jun. 30, 2022 USD ($) | Jun. 30, 2021 | Jun. 28, 2021 serviceConnection residence | Jun. 23, 2021 | May 27, 2021 USD ($) | May 03, 2021 USD ($) | Mar. 16, 2021 USD ($) | Mar. 10, 2021 USD ($) | Mar. 03, 2021 | Feb. 01, 2021 | Jan. 04, 2021 USD ($) | Nov. 16, 2020 USD ($)
San Jose Water Company | General Rate Case No. 21-01-003 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, requested rate increase, year one |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 51,585,000 | $ 11,750,000
Regulatory rate filings, requested rate increase as percentage of total revenue at time of request, year one |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 13.35% | 3.04%
Regulatory rate filings, requested rate increase, year two |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 16,932,000 |
Regulatory rate filings, proposed rate increase, percent of authorized revenue, year two |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.88% |
Regulatory rate filings, requested rate increase, year three |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 19,195,000 |
Regulatory rate filings, requested rate increase, percent of authorized revenue, year three |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.24% |
Regulatory rate filings, balancing and memorandum account, requested recovery (refund) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 18,499,000 |
Regulatory rate filings, requested authorization for capital budget, amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 435,000,000 |
San Jose Water Company | General Rate Case No. 21-05-004 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, requested rate increase, year one |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 6,418,000 |  |  |  |  |  |
Regulatory rate filings, requested rate increase as percentage of total revenue at time of request, year one |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.61% |  |  |  |  |  |
Regulatory rate filings, rate of return, requested |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8.11% |  |  |  |  |  |
Regulatory rate filings, rate of return, current |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7.64% |  |  |  |  |  |
Regulatory rate filings, average cost of debt rate, requested |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.20% |  |  |  |  |  |
Regulatory rate filings, average cost of debt rate, current |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.48% |  |  |  |  |  |
Regulatory rate filings, return of equity rate, requested |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10.30% |  |  |  |  |  |
Regulatory rate filings, return of equity rate, current |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8.90% |  |  |  |  |  |
Regulatory rate filings, capital structure, debt percentage, current |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 47.00% |  |  |  |  |  |
Regulatory rate filings, capital structure, equity percentage, current |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 53.00% |  |  |  |  |  |
Regulatory rate filings, capital structure, debt percentage, requested |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 45.00% |  |  |  |  |  |
Regulatory rate filings, capital structure, equity percentage, requested |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 55.00% |  |  |  |  |  |
San Jose Water Company | Advice Letter No. 561/561A |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, requested rate increase, year one |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 17,262,000 |  |  |  |  |  |  |
Regulatory rate filings, requested rate increase as percentage of total revenue at time of request, year one |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.34% |  |  |  |  |  |  |
Connecticut Water Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public utilities, requested rate increase (decrease), amount |  |  |  |  |  |  |  | $ 956,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Requested WICA surcharge, percentage |  |  |  |  |  |  |  | 6.94% |  |  |  |  |  |  |  |  |  | 7.03% |  |  |
Authorized WICA surcharge, percentage |  |  |  |  |  |  |  |  |  |  | 7.03% |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, requested increase in revenues |  |  |  |  | $ 20,206,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested increase in revenues, completed infrastructure investments not currently in approved rates and surcharges |  |  |  |  | $ 265,514,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, requested reduction in water bills for income-eligible customers |  |  |  |  | 15.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Connecticut Water Company | Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, approved revenue increase | $ 5,208,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, return of equity rate, approved | 9.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, statutory cap reset value | $ 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Connecticut Water Company | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, requested authorization for debt issuance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 100,000,000 |  |  |  |  |
Connecticut Water Company | WICA |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested WICA surcharge increase (decrease), percentage |  |  |  |  |  |  |  | 1.11% |  |  |  |  |  |  |  |  |  |  | 0.09% |  |
Avon Water Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Authorized WICA surcharge, percentage |  |  |  |  |  |  |  |  |  |  | 8.51% |  |  |  |  |  |  |  |  |  |
CLWSC |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Authorized regulatory surcharge, per thousand gallons |  | $ 0.7 | $ 1.84 | $ 0.95 |  | $ 2.02 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Authorized regulatory base charge, per residential account |  |  | $ 0.51 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Potential increase in number of service connections | serviceConnection |  |  |  |  |  |  |  |  |  |  |  | 1,400 |  |  |  |  |  |  |  |  |
Number of county residences served | residence |  |  |  |  |  |  |  |  |  |  |  | 4 |  |  |  |  |  |  |  |  |
Maine Water Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, requested rate increase, year one |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 6,659,000 |  |  |  |
Regulatory rate filings, requested rate increase as percentage of total revenue at time of request, year one |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 77.50% |  |  |  |
Public utilities, requested rate increase (decrease), amount |  |  |  |  |  |  | $ 304,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Approved rate increase (decrease) |  |  |  |  |  |  |  |  | $ 198,000 |  |  |  |  |  |  |  |  |  |  |  |
Approved rate increase (decrease), step increase 1 |  |  |  |  |  |  |  |  | 9.80% |  |  |  |  |  |  |  |  |  |  |  |
Approved rate increase (decrease), step increase 2 |  |  |  |  |  |  |  |  | 3.51% |  |  |  |  |  |  |  |  |  |  |  |
Approved rate increase (decrease) |  |  |  |  |  |  |  |  | 13.31% |  |  |  |  |  |  |  |  |  |  |  |
Authorized temporary surcharge, percentage |  |  |  |  |  |  |  |  |  |  |  |  | 22.65% |  |  |  |  |  |  |  |
Maine Water Company | Forecast |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory rate filings, requested project replacement value |  |  |  |  |  |  |  |  |  | $ 60,000,000 |  |  |  |  |  |  |  |  |  |  |
Maine Water Company | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested WISC surcharge increase (decrease), percentage |  |  |  |  |  |  | 5.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maine Water Company | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested WISC surcharge increase (decrease), percentage |  |  |  |  |  |  | 1.10% |  |  |  |  |  |  |  |  |  |  |  |  |  |

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