Regulatory Rate Filings (Details) - USD ($)	Aug. 30, 2019	Sep. 14, 2018	Oct. 18, 2019	Aug. 01, 2019	Jul. 26, 2019	Mar. 29, 2019	Feb. 08, 2019
Public Utilities, General Disclosures [Line Items]
CPED Calculated Double-Billing Refund		$ 4,935,000
Minimum
Public Utilities, General Disclosures [Line Items]
CPED Proposed Penalty, Per Offense, Per Day		500
Maximum
Public Utilities, General Disclosures [Line Items]
CPED Proposed Penalty, Per Offense, Per Day		50,000
Advice Letter No. 534
Public Utilities, General Disclosures [Line Items]
Memorandum Account, Requested Recovery				$ 1,243,000
Advice Letter No. 530
Public Utilities, General Disclosures [Line Items]
Approved Service Charge Refund							$ 2,020,000
CPED Calculated Refund 2014-2016
Public Utilities, General Disclosures [Line Items]
CPED Calculated Service Charge Refund		2,061,000
CPED Calculated Refund 1987-2013
Public Utilities, General Disclosures [Line Items]
CPED Calculated Service Charge Refund		$ 1,990,000
OII No. 18-09-003 Settlement Agreement
Public Utilities, General Disclosures [Line Items]
Customer Credit Refund					$ 350,000
Utility Plant Investment Commitment					5,000,000
OII No. 18-09-003 Settlement Agreement | Minimum
Public Utilities, General Disclosures [Line Items]
Customer Credit Refund					1,757,000
OII No. 18-09-003 Settlement Agreement | Maximum
Public Utilities, General Disclosures [Line Items]
Customer Credit Refund					$ 2,100,000
Advice Letter No. 535
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 655,000
Public Utilities, Requested Rate Increase (Decrease), Percentage	0.17%
2018 WCMA | Advice Letter No. 532
Public Utilities, General Disclosures [Line Items]
Memorandum Account, Requested Recovery						$ 9,020,000
Subsequent Event | Advice Letter No. 537
Public Utilities, General Disclosures [Line Items]
Memorandum Account, Requested Refund, Monthly Amount			$ 1.74