XML 67 R35.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Summary of Significant Accounting Policies (Utility Plant) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Capitalized interest costs | $ 2,188 | $ 1,188 | $ 1,112
Construction in progress | 70,453 | 45,573 |
Major components of depreciable plant and equipment [Abstract] |  |  |
Equipment | 269,734 | 254,940 |
Transmission and distribution | 1,204,520 | 1,108,659 |
Office buildings and other structures | 79,762 | 74,722 |
Total depreciable plant and equipment | $ 1,554,016 | $ 1,438,321 |
Estimated Useful Lives of Plant and Equipment [Abstract] |  |  |
Depreciation expense as percentage of beginning of year balance of depreciable plant | 3.50% | 3.40% | 3.40%
Minimum [Member] |  |  |
Estimated Useful Lives of Plant and Equipment [Abstract] |  |  |
Estimated useful life of equipment | 5 years |  |
Estimated useful life of transmission and distribution plant | 35 years |  |
Estimated useful lives of office buildings and other structures | 7 years |  |
Estimated service lives of assets | 5 years |  |
Maximum [Member] |  |  |
Estimated Useful Lives of Plant and Equipment [Abstract] |  |  |
Estimated useful life of equipment | 35 years |  |
Estimated useful life of transmission and distribution plant | 75 years |  |
Estimated useful lives of office buildings and other structures | 50 years |  |
Estimated service lives of assets | 75 years |  |
General and Administrative Expense [Member] |  |  |
Estimated Useful Lives of Plant and Equipment [Abstract] |  |  |
Depreciation | $ 1,670 | $ 1,590 | $ 1,586
Water Plant [Member] |  |  |
Estimated Useful Lives of Plant and Equipment [Abstract] |  |  |
Depreciation | $ 42,659 | $ 38,722 | $ 35,918

X
- Definition Estimated Useful Lives of Plant and Equipment [Abstract] + References No definition available. + Details
Name: | sjw_EstimatedUsefulLivesOfPlantAndEquipmentAbstract
Namespace Prefix: | sjw_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 + Details
Name: | us-gaap_Depreciation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest capitalized during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Allowance for Funds Used during Construction -URI http://asc.fasb.org/extlink&oid=6504829 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 + Details
Name: | us-gaap_InterestCostsCapitalized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of assets common to business units owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommonUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period end amount of construction work in progress in public utility. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Composite depreciation rate for public utility plants in service. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period end book value of equipment owned (but not classified elsewhere) by the public utility. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Useful life of other equipment owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period end book value of other property, plant and equipment (PPE) owned (but not classified elsewhere) by the public utility. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Useful life of other property, plant and equipment (PPE) owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period end amount of total gross PPE. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Period end amount of property, plant and equipment (PPE) related to transmission and distribution owned by public utility. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Useful life of utility transmission and distribution equipment owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistributionUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
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_PublicUtilityPropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_GeneralAndAdministrativeExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=us-gaap_WaterPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |