Regulatory Matters: (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Regulatory matters:
Regulatory asset not accruing carrying costs	$ 54,000
Pension and other post-retirement obligations
Regulatory matters:
Regulatory asset not accruing carrying costs	23,700
Derivative unrealized loss
Regulatory matters:
Regulatory asset not accruing carrying costs	7,200
Flow-through taxes, net
Regulatory matters:
Regulatory asset not accruing carrying costs	16,600
GOLDEN STATE WATER COMPANY
Regulatory matters:
Regulatory assets	144,198	$ 132,696
GOLDEN STATE WATER COMPANY | Water Revenue Adjustment Mechanism, net of Modified Cost Balancing Account
Regulatory matters:
Regulatory assets	53,948	45,171
GOLDEN STATE WATER COMPANY | Costs deferred for future recovery on Aerojet case
Regulatory matters:
Regulatory assets	12,567	12,699
GOLDEN STATE WATER COMPANY | Pension and other post-retirement obligations
Regulatory matters:
Regulatory assets	25,538	21,996
GOLDEN STATE WATER COMPANY | Derivative unrealized loss
Regulatory matters:
Regulatory assets	7,245	7,053
GOLDEN STATE WATER COMPANY | Flow-through taxes, net
Regulatory matters:
Regulatory assets	16,551	16,176
GOLDEN STATE WATER COMPANY | Low income rate assistance balancing accounts
Regulatory matters:
Regulatory assets	8,810	8,699
GOLDEN STATE WATER COMPANY | Other regulatory assets
Regulatory matters:
Regulatory assets	25,298	25,668
Various refunds to customers | GOLDEN STATE WATER COMPANY
Regulatory matters:
Regulatory assets	$ (5,759)	$ (4,766)