CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Cash Flows from Operating Activities
Net income	$ 567	$ 553	$ 32	$ 1,542
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and decommissioning			2,257	2,134
Allowance for equity funds used during construction			(97)	(63)
Deferred income taxes and tax credits, net			10	848
Disallowed capital expenditures			(38)	47
Other			231	204
Effect of changes in operating assets and liabilities:
Accounts receivable			(201)	(58)
Wildfire-related insurance receivable			64	(166)
Inventories			(24)	(35)
Accounts payable			245	76
Wildfire-related claims			2,233	12
Income taxes receivable/payable			0	135
Other current assets and liabilities			(154)	23
Regulatory assets, liabilities, and balancing accounts, net			(128)	(30)
Other noncurrent assets and liabilities			(194)	68
Net cash provided by operating activities			4,236	4,737
Cash Flows from Investing Activities
Capital expenditures			(4,592)	(3,938)
Proceeds from sales and maturities of nuclear decommissioning trust investments	319	249	1,121	1,043
Purchases of nuclear decommissioning trust investments			(1,165)	(1,071)
Other			19	16
Net cash used in investing activities			(4,617)	(3,950)
Cash Flows from Financing Activities
Borrowings under revolving credit facilities			775	0
Repayments under revolving credit facilities			(775)	0
Net issuances (repayments) of commercial paper, net of discount			(182)	(652)
Short-term debt financing			250	250
Short-term debt matured			(250)	(250)
Proceeds from issuance of long-term debt, net of discount and issuance costs of $7 and $11 at respective dates			1,143	734
Long-term debt matured or repurchased			(750)	(345)
Common stock issued			137	345
Common stock dividends paid			0	(754)
Other			14	(101)
Net cash provided by (used in) financing activities			362	(773)
Net change in cash and cash equivalents			(19)	14
Cash and cash equivalents at January 1			449	177	$ 177
Cash and cash equivalents at September 30	430	191	430	191	449
Supplemental disclosures of cash flow information
Interest, net of amounts capitalized			(650)	(644)
Income taxes, net			(49)	158
Supplemental disclosures of noncash investing and financing activities
Common stock dividends declared but not yet paid	0	272	0	272
Capital expenditures financed through accounts payable			348	301
Noncash common stock issuances			0	16
Terminated capital leases			161	0
Pacific Gas & Electric Co
Cash Flows from Operating Activities
Net income	571	513	47	1,491
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and decommissioning			2,257	2,134
Allowance for equity funds used during construction			(97)	(63)
Deferred income taxes and tax credits, net			5	848
Disallowed capital expenditures			(38)	47
Other			170	196
Effect of changes in operating assets and liabilities:
Accounts receivable			(200)	(58)
Wildfire-related insurance receivable			64	(166)
Inventories			(24)	(35)
Accounts payable			245	76
Wildfire-related claims			2,233	12
Income taxes receivable/payable			0	135
Other current assets and liabilities			(156)	36
Regulatory assets, liabilities, and balancing accounts, net			(128)	(30)
Other noncurrent assets and liabilities			(194)	69
Net cash provided by operating activities			4,184	4,692
Cash Flows from Investing Activities
Capital expenditures			(4,592)	(3,938)
Proceeds from sales and maturities of nuclear decommissioning trust investments			1,121	1,043
Purchases of nuclear decommissioning trust investments			(1,165)	(1,071)
Other			19	16
Net cash used in investing activities			(4,617)	(3,950)
Cash Flows from Financing Activities
Borrowings under revolving credit facilities			650	0
Repayments under revolving credit facilities			(650)	0
Net issuances (repayments) of commercial paper, net of discount			(50)	(652)
Short-term debt financing			250	250
Short-term debt matured			(250)	(250)
Proceeds from issuance of long-term debt, net of discount and issuance costs of $7 and $11 at respective dates			793	734
Long-term debt matured or repurchased			(400)	(345)
Preferred stock dividends paid			0	(10)
Common stock dividends paid			0	(784)
Equity contribution from PG&E Corporation			0	405
Other			14	(91)
Net cash provided by (used in) financing activities			357	(743)
Net change in cash and cash equivalents			(76)	(1)
Cash and cash equivalents at January 1			447	71	71
Cash and cash equivalents at September 30	$ 371	$ 70	371	70	$ 447
Supplemental disclosures of cash flow information
Interest, net of amounts capitalized			(640)	(636)
Income taxes, net			(59)	158
Supplemental disclosures of noncash investing and financing activities
Capital expenditures financed through accounts payable			348	301
Terminated capital leases			$ 161	$ 0