COMMITMENTS AND CONTINGENCIES - NUCLEAR INSURANCE (Details) - San Diego Gas and Electric Company [Member] $ in Thousands	Sep. 30, 2016 USD ($)
Schedule Of Nuclear Insurance [Line Items]
Maximum nuclear liability insurance coverage	$ 375,000
Maximum secondary financial protection	13,200,000
Maximum company contribution to secondary financial protection	50,930
Annual maximum secondary financial protection contribution by company	7,600
Maximum nuclear property insurance coverage	2,750,000
Deductible per loss	2,500
Maximum premium assessment under nuclear property damage insurance	9,700
Maximum nuclear property insurance terrorism coverage	$ 3,240,000