CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Cash Flows from Operating Activities
Net income (loss)	$ (980)	$ 410	$ (535)	$ 989
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and decommissioning			1,498	1,424
Allowance for equity funds used during construction			(63)	(34)
Deferred income taxes and tax credits, net			(145)	516
Disallowed capital expenditures			0	47
Other			104	121
Effect of changes in operating assets and liabilities:
Accounts receivable			(11)	111
Wildfire-related insurance receivable			(144)	54
Inventories			(6)	(38)
Accounts payable			39	19
Wildfire-related claims			2,299	(116)
Income taxes receivable/payable			0	67
Other current assets and liabilities			(103)	(92)
Regulatory assets, liabilities, and balancing accounts, net			(12)	(353)
Other noncurrent assets and liabilities			(168)	41
Net cash provided by operating activities			2,753	2,756
Cash Flows from Investing Activities
Capital expenditures			(2,897)	(2,474)
Proceeds from sales and maturities of nuclear decommissioning trust investments	308	324	802	794
Purchases of nuclear decommissioning trust investments			(815)	(817)
Other			15	8
Net cash used in investing activities			(2,895)	(2,489)
Cash Flows from Financing Activities
Borrowings under revolving credit facilities			700	0
Net issuances (repayments) of commercial paper, net of discount			(182)	(339)
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			350	734
Long-term debt matured or repurchased			(750)	(345)
Common stock issued			82	247
Common stock dividends paid			0	(488)
Other			10	(75)
Net cash provided by (used in) financing activities			210	(266)
Net change in cash and cash equivalents			68	1
Cash and cash equivalents at January 1			449	177	$ 177
Cash and cash equivalents at June 30	517	178	517	178	449
Supplemental disclosures of cash flow information
Interest, net of amounts capitalized			(394)	(395)
Income taxes, net			0	68
Supplemental disclosures of noncash investing and financing activities
Common stock dividends declared but not yet paid	0	271	0	271
Capital expenditures financed through accounts payable			317	268
Noncash common stock issuances			0	10
Terminated capital leases			137	0
Pacific Gas & Electric Co
Cash Flows from Operating Activities
Net income (loss)	(976)	409	(524)	978
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and decommissioning			1,498	1,424
Allowance for equity funds used during construction			(63)	(34)
Deferred income taxes and tax credits, net			(149)	534
Disallowed capital expenditures			0	47
Other			57	127
Effect of changes in operating assets and liabilities:
Accounts receivable			(11)	113
Wildfire-related insurance receivable			(144)	54
Inventories			(6)	(38)
Accounts payable			40	45
Wildfire-related claims			2,299	(116)
Income taxes receivable/payable			0	75
Other current assets and liabilities			(95)	(72)
Regulatory assets, liabilities, and balancing accounts, net			(12)	(353)
Other noncurrent assets and liabilities			(168)	40
Net cash provided by operating activities			2,722	2,824
Cash Flows from Investing Activities
Capital expenditures			(2,897)	(2,474)
Proceeds from sales and maturities of nuclear decommissioning trust investments			802	794
Purchases of nuclear decommissioning trust investments			(815)	(817)
Other			15	8
Net cash used in investing activities			(2,895)	(2,489)
Cash Flows from Financing Activities
Borrowings under revolving credit facilities			650	0
Net issuances (repayments) of commercial paper, net of discount			(50)	(339)
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			0	734
Long-term debt matured or repurchased			(400)	(345)
Preferred stock dividends paid			0	(7)
Common stock dividends paid			0	(514)
Equity contribution from PG&E Corporation			0	190
Other			10	(68)
Net cash provided by (used in) financing activities			210	(349)
Net change in cash and cash equivalents			37	(14)
Cash and cash equivalents at January 1			447	71	71
Cash and cash equivalents at June 30	$ 484	$ 57	484	57	$ 447
Supplemental disclosures of cash flow information
Interest, net of amounts capitalized			(387)	(390)
Income taxes, net			0	76
Supplemental disclosures of noncash investing and financing activities
Capital expenditures financed through accounts payable			317	268
Terminated capital leases			$ 137	$ 0