Commitments And Contingencies (Legal And Regulatory Contingencies) (Details) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)		Jun. 30, 2017 USD ($)	Dec. 31, 2015 USD ($)
Loss Contingencies [Line Items]
Unrecognized Tax Benefits	$ 70,000	$ 70,000
Disputed Claims Liability Balance				$ 236,000
Release of Escrow to California Power Exchange		0	$ (66,000)
Charge for disallowed capital		$ 47,000	517,000
Butte Fire [Member]
Loss Contingencies [Line Items]
Number of plaintiffs	3,770	3,770
Utility liability insurance for damages		$ 922,000
Number of Damaged Structures	44	44
Loss Contingency Range Of Possible Loss Minimum	$ 1,100,000	$ 1,100,000				$ 750,000
Number of complaints filed against utility	77	77
Fire Fighting Costs Recovery Requested By Cal Fire		$ 87,000
Number Of Acres Burned	70,868	70,868
Number Of Fatalities Caused By Fire	2	2
Number Of Homes Burned By Fire	549	549
Number Of Outbuildings Burned By Fire	368	368
Number Of Commerical Properties Burned By Fire	4	4
Number Of Households Represented In Court	2,080	2,080
Number Of Master Complaints	2	2
Cumulative Legal Expenses	$ 18,000	$ 45,000
Vegetation Management Contractors	2	2
Number Of Preference Households	1	1
Citation For Failing To Maintain Electric Line		$ 8,300
Office Of Emergency Services Claim		$ 190,000
Number of Citations		2
Probable Insurance Recoveries		$ 922,000
Settlement Agreements Entered By Utility		515,000
Settlement Agreement Paid By The Utility	$ 398,000
Claim Against The Utility		$ 85,000
NumberOf Preference Households Settled	6	6
Number Of Preference Plaintiffs	1	1
Insurance Recoveries	$ 21,000	$ 53,000
Number Of Households With Inestimable Losses	1,000	1,000
Potential Safety Citations [Member]
Loss Contingencies [Line Items]
SED Maximum Statutory Penalty Per Violaiton		$ 50
SED Administrative Limit Per Citation		8,000
Valero Refinery Outage [Member]
Loss Contingencies [Line Items]
Loss Contingency Range Of Possible Loss Minimum	$ 114,000	114,000
Initial Claim		$ 75,000
Ghost Ship Fire [Member]
Loss Contingencies [Line Items]
Number Of Fatalities Caused By Fire	36	36
Lawsuits Filed Against Property Owner	34	34
Yuba City [Member]
Loss Contingencies [Line Items]
Number of People Injured	2	2
Number Of Violations	2	2
Minimum [Member] | Potential Safety Citations [Member]
Loss Contingencies [Line Items]
SED fines for self-reported violations		$ 50
Maximum [Member] | Potential Safety Citations [Member]
Loss Contingencies [Line Items]
SED fines for self-reported violations		16,800
Maximum [Member] | Yuba City [Member]
Loss Contingencies [Line Items]
SED recommended penalty		8,000
Ex Parte Communications [Member]
Loss Contingencies [Line Items]
Payment To State General Fund		12,000
Payment To City Of San Bruno		6,000
Payment To City Of San Carlos		6,000
Revenue Requirement Reduction In Next GRC Cycle		10,000
2018 GT&S Revenue Requirement Reduction		31,750
2019 GT&S Revenue Requirement Reduction		31,750
Initial Payment To California General Fund		$ 1,000
Shareholder Derivative Lawsuits [Member]
Loss Contingencies [Line Items]
Number Of Unconsolidated Cases In Derivative Lawsuits	3	3
Estimated Cost Of Corporate Governance Therapeutics		$ 32,000
Payment Of Individual Defendant Costs		18,300
Number Of Years Of Corporate Governance Therapeutics	5 years
Number Of Years Of Gas Operations Therapeutics	3 years
Insurance Recoveries		65,000
Loss Accrual [Member] | Butte Fire [Member]
Loss Contingencies [Line Items]
Accrued Losses		350,000		750,000
Loss Contingency Accrual At Carrying Value	$ 702,000	702,000		690,000			$ 0
Payments For Claims		338,000		60,000	[1]
Insurance Receivable [Member] | Butte Fire [Member]
Loss Contingencies [Line Items]
Insurance Reimbursement From Contractors		131,000		50,000
Insurance Settlements Receivable	741,000	741,000		575,000			$ 0
Accrued Insurance Recoveries	$ 297,000	297,000		625,000
Cumulative Legal Expenses [Member] | Butte Fire [Member]
Loss Contingencies [Line Items]
Cumulative Legal Expenses		$ 72,000
Disallowance Of Plant Costs [Member]
Loss Contingencies [Line Items]
Percentage of Recoverable Costs Prior To Specific Date	100.00%	100.00%
Percentage of Recoverable Costs After Specific Date	25.00%	25.00%
Settlement Agreement Length	8 years
License Renewal Project Cost		$ 53,000
Recoverable Costs From Customers		18,600
Cancelled Capital Project Costs		24,000
Disallowed License Renewal Costs		23,000
Pacific Gas And Electric Company [Member]
Loss Contingencies [Line Items]
Release of Escrow to California Power Exchange		0	(66,000)
Charge for disallowed capital		47,000	$ 517,000
Utility [Member]
Loss Contingencies [Line Items]
Accrued legal liabilities	$ 39,000	$ 39,000		$ 45,000

[1] As of September 30, 2017 the Utility entered into settlement agreements in connection with the Butte fire corresponding to approximately $515 of which $398 million has been paid by the Utility.