XML 58 R42.htm IDEA: XBRL DOCUMENT
v3.20.1

Condensed Consolidating Financial Statements - Additional Information (Details) - USD ($) | Mar. 31, 2020 | Nov. 17, 2010
--- | --- | ---
Cal Water |  |
Debt Instrument [Line Items] |  |
Ownership interest (as a percent) | 100.00% |
All Other Subsidiaries |  |
Debt Instrument [Line Items] |  |
Ownership interest (as a percent) | 100.00% |
First Mortgage Bonds, 5.500% due 2040 | Cal Water |  |
Debt Instrument [Line Items] |  |
Debt issued |  | $ 100,000,000.0
Interest rate |  | 5.50%

X
- Definition Represents the ownership interest percentage of the parent in consolidated subsidiaries. + References No definition available. + Details
Name: | cwt_OwnershipInterestPercentageOfParentInConsolidatedSubsidiaries
Namespace Prefix: | cwt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=cwt_CalWaterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=cwt_AllOtherSubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=cwt_FirstMortgageBondsPPPSeriesDue2040Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |