Balancing and Memorandum Account Recovery Procedures (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Memorandum Accounts [Roll Forward]
Beginning Balance	$ 4,357	$ 8,910
Revenue Increase(Reduction)	4,179	3,511
Refunds (Collections)	(991)	(518)
Surcharge Offset	(3,467)	(3,014)
Ending Balance	4,078	8,889
Balancing Accounts [Roll Forward]
Beginning Balance	21,552	36,296
Revenue Increase(Reduction)	156	(163)
Refunds (Collections)	(5,262)	(5,853)
Surcharge Offset	3,543	3,014
Ending Balance	19,989	33,294
Balancing and Memorandum Account [Roll Forward]
Beginning Balance	25,909	45,206
Revenue Increase (Reduction)	4,335	3,348
Refunds (Collections)	(6,253)	(6,371)
Surcharge Offset	76	0
Ending Balance	24,067	42,183
Net under-collected balancing and memorandum accounts	3,361
2014 WCMA
Memorandum Accounts [Roll Forward]
Beginning Balance	0	2,944
Revenue Increase(Reduction)	112	0
Refunds (Collections)	(112)	(517)
Surcharge Offset	0	0
Ending Balance	0	2,427
Balancing and Memorandum Account [Roll Forward]
WCMA Reserve	978	1,278
2015 WCMA
Memorandum Accounts [Roll Forward]
Beginning Balance	1,589	5,372
Revenue Increase(Reduction)	(71)	(20)
Refunds (Collections)	(1,120)	0
Surcharge Offset	0	0
Ending Balance	398	5,352
Balancing and Memorandum Account [Roll Forward]
WCMA Reserve	2,183	2,343
2016 WCMA
Memorandum Accounts [Roll Forward]
Beginning Balance	0	0
Revenue Increase(Reduction)	1,407	3,014
Refunds (Collections)	0	0
Surcharge Offset	(1,407)	(3,014)
Ending Balance	0	0
Balancing and Memorandum Account [Roll Forward]
Interest	36
2016 WCMA Asset
Memorandum Accounts [Roll Forward]
Revenue Increase(Reduction)	1,371
2017 WCMA
Memorandum Accounts [Roll Forward]
Beginning Balance	0	0
Revenue Increase(Reduction)	2,060	0
Refunds (Collections)	0	0
Surcharge Offset	(2,060)	0
Ending Balance	0	0
Water supply costs
Balancing Accounts [Roll Forward]
Beginning Balance	5,190	2,771
Revenue Increase(Reduction)	197	(313)
Refunds (Collections)	297	(22)
Surcharge Offset	0	0
Ending Balance	5,684	2,436
Drought surcharges
Balancing Accounts [Roll Forward]
Beginning Balance	(7,688)	(359)
Revenue Increase(Reduction)	0	0
Refunds (Collections)	(833)	(3,167)
Surcharge Offset	3,467	3,014
Ending Balance	(5,054)	(512)
Pension
Balancing Accounts [Roll Forward]
Beginning Balance	(2,009)	(552)
Revenue Increase(Reduction)	173	280
Refunds (Collections)	(703)	(155)
Surcharge Offset	0	0
Ending Balance	(2,539)	(427)
2012 General Rate Case true-up
Balancing Accounts [Roll Forward]
Beginning Balance	20,682	33,070
Revenue Increase(Reduction)	0	0
Refunds (Collections)	(2,258)	(2,498)
Surcharge Offset	0	0
Ending Balance	18,424	30,572
2015 General Rate Case true-up
Balancing Accounts [Roll Forward]
Beginning Balance	5,528	0
Revenue Increase(Reduction)	0	0
Refunds (Collections)	(1,431)	0
Surcharge Offset	0	0
Ending Balance	4,097	0
All others
Memorandum Accounts [Roll Forward]
Beginning Balance	2,768	594
Revenue Increase(Reduction)	671	517
Refunds (Collections)	241	(1)
Surcharge Offset	0	0
Ending Balance	3,680	1,110
Balancing Accounts [Roll Forward]
Beginning Balance	(151)	1,366
Revenue Increase(Reduction)	(214)	(130)
Refunds (Collections)	(334)	(11)
Surcharge Offset	76	0
Ending Balance	$ (623)	$ 1,225

This represents the under-collection or over-collection associated with expense changes and the revenue authorized by the CPUC to offset those expense changes. Pursuant to Section 792.5 of the California Public Utilities Code, a balancing account must be maintained for expense items for which revenue offsets have been authorized. Since the amounts in the balancing accounts must be approved by the CPUC before they can be incorporated into rates, the Company does not recognize balancing accounts in its revenue until CPUC approval occurs. It is typical for the CPUC to incorporate any over-collected and/or under-collected balances in balancing accounts into customer rates at the time rate decisions are made as part of the Company’s general rate case proceedings by assessing temporary surcredits and/or surcharges.

No definition available.