Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities
Net income	$ 1,660	$ 1,407	$ 888
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and decommissioning	2,854	2,755	2,612
Allowance for equity funds used during construction	(89)	(112)	(107)
Deferred income taxes and tax credits, net	1,254	1,030	693
Charge for disallowed capital	47	507	407
Other	307	379	326
Butte-related third-party claims	(129)	690	0
Butte-related insurance receivable	21	575	0
Effect of changes in operating assets and liabilities:
Accounts receivable	67	(473)	(177)
Inventories	(18)	(24)	37
Accounts payable	173	180	(55)
Income taxes receivable/payable	160	(5)	43
Other current assets and liabilities	42	83	(288)
Regulatory assets, liabilities, and balancing accounts, net	(387)	(1,214)	(244)
Other noncurrent assets and liabilities	57	(219)	(355)
Net cash provided by operating activities	5,977	4,409	3,780
Cash Flows from Investing Activities
Capital expenditures	(5,641)	(5,709)	(5,173)
Decrease in restricted cash	0	227	64
Proceeds from sales and maturities of nuclear decommissioning trust investments	1,291	1,295	1,268
Purchases of nuclear decommissioning trust investments	(1,323)	(1,352)	(1,392)
Other	23	13	22
Net cash used in investing activities	(5,650)	(5,526)	(5,211)
Cash Flows from Financing Activities
Net issuances (repayments) of commercial paper, net of discount of $5, $6, and $3 at respective dates	(840)	(9)	683
Short-term debt financing	750	500	0
Short-term debt matured	(500)	0	(300)
Proceeds from issuance of long-term debt, net of premium, discount and issuance costs of $32, $17 and $27 at respective dates	2,713	983	1,123
Repayments of long-term debt	(1,445)	(160)	0
Common stock issued	395	822	780
Common stock dividends paid	(1,021)	(921)	(856)
Other	(107)	(44)	(27)
Net cash provided by (used in) financing activities	(55)	1,171	1,403
Net change in cash and cash equivalents	272	54	(28)
Cash and cash equivalents at January 1	177	123	151
Cash and cash equivalents at December 31	449	177	123
Cash received (paid) for:
Interest, net of amounts capitalized	(790)	(726)	(684)
Income taxes, net	162	231	77
Supplemental disclosures of noncash investing and financing activities
Common stock dividends declared but not yet paid	0	248	224
Capital expenditures financed through accounts payable	501	403	440
Noncash common stock issuances	21	20	21
Terminated Capital Leases	23	18	0
Pacific Gas And Electric Company [Member]
Cash Flows from Operating Activities
Net income	1,691	1,402	862
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and decommissioning	2,854	2,754	2,611
Allowance for equity funds used during construction	(89)	(112)	(107)
Deferred income taxes and tax credits, net	1,103	1,042	714
Charge for disallowed capital	47	507	407
Other	283	306	263
Butte-related third-party claims	(129)	690	0
Butte-related insurance receivable	21	575	0
Effect of changes in operating assets and liabilities:
Accounts receivable	66	(475)	(177)
Inventories	(18)	(24)	37
Accounts payable	173	179	(2)
Income taxes receivable/payable	159	(29)	38
Other current assets and liabilities	59	112	(315)
Regulatory assets, liabilities, and balancing accounts, net	(390)	(1,214)	(244)
Other noncurrent assets and liabilities	128	(219)	(340)
Net cash provided by operating activities	5,916	4,344	3,747
Cash Flows from Investing Activities
Capital expenditures	(5,641)	(5,709)	(5,173)
Decrease in restricted cash	0	227	64
Proceeds from sales and maturities of nuclear decommissioning trust investments	1,291	1,295	1,268
Purchases of nuclear decommissioning trust investments	(1,323)	(1,352)	(1,392)
Other	23	13	22
Net cash used in investing activities	(5,650)	(5,526)	(5,211)
Cash Flows from Financing Activities
Net issuances (repayments) of commercial paper, net of discount of $5, $6, and $3 at respective dates	(972)	(9)	683
Short-term debt financing	750	500	0
Short-term debt matured	(500)	0	(300)
Proceeds from issuance of long-term debt, net of premium, discount and issuance costs of $32, $17 and $27 at respective dates	2,713	983	1,123
Repayments of long-term debt	(1,445)	(160)	0
Preferred stock dividends paid	(14)	(14)	(14)
Common stock dividends paid	(784)	(911)	(716)
Equity contribution from PG&E Corporation	455	835	705
Other	(93)	(30)	(13)
Net cash provided by (used in) financing activities	110	1,194	1,468
Net change in cash and cash equivalents	376	12	4
Cash and cash equivalents at January 1	71	59	55
Cash and cash equivalents at December 31	447	71	59
Cash received (paid) for:
Interest, net of amounts capitalized	(781)	(717)	(675)
Income taxes, net	162	244	77
Supplemental disclosures of noncash investing and financing activities
Capital expenditures financed through accounts payable	501	403	440
Terminated Capital Leases	$ 23	$ 18	$ 0