SCHEDULE I – CONDENSED FINANCIAL INFORMATION OF PARENT (Schedule of Condensed Income Statement and Comprehensive Income) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating expenses	$ (16,714)	$ (27,223)	$ (26,459)
Interest income	39	82	76
Interest expense	(1,260)	(934)	(929)
Other income, net	483	250	424
Reorganization items, net	(1,959)	(346)	0
Loss Before Income Taxes	(942)	(11,042)	(10,129)
Income tax provision (benefit)	362	(3,400)	(3,292)
Loss Attributable to Common Shareholders	(1,318)	(7,656)	(6,851)
Other Comprehensive Income (Loss)
Pension and other postretirement benefit plans obligations	(17)	(1)	4
Total other comprehensive income (loss)	$ (17)	$ (1)	$ 4
Weighted Average Common Shares Outstanding, Basic (in shares)	1,257	528	517
Weighted Average Common Shares Outstanding, Diluted (in shares)	1,257	528	517
Net Loss Per Common Share, Basic (in dollars per share)	$ (1.05)	$ (14.50)	$ (13.25)
Net Loss Per Common Share, Diluted (in dollars per share)	$ (1.05)	$ (14.50)	$ (13.25)
Pension and other postretirement benefit plans obligations, tax	$ 7	$ 0	$ 2
PG&E Corporation
Operating expenses	(103)	(114)	(91)
Interest income	0	1	2
Interest expense	(149)	(21)	(15)
Other income, net	13	10	(2)
Reorganization items, net	(1,649)	(26)	0
Equity in earnings of subsidiaries	411	(7,622)	(6,832)
Loss Before Income Taxes	(1,350)	(7,634)	(6,848)
Income tax provision (benefit)	(46)	8	3
Loss Attributable to Common Shareholders	(1,304)	(7,642)	(6,851)
Other Comprehensive Income (Loss)
Pension and other postretirement benefit plans obligations	(17)	(1)	4
Total other comprehensive income (loss)	(17)	(1)	4
Comprehensive Loss	$ (1,321)	$ (7,643)	$ (6,847)
Weighted Average Common Shares Outstanding, Basic (in shares)	1,257	528	517
Weighted Average Common Shares Outstanding, Diluted (in shares)	1,257	528	513
Net Loss Per Common Share, Basic (in dollars per share)	$ (1.05)	$ (14.50)	$ (13.25)
Net Loss Per Common Share, Diluted (in dollars per share)	$ (1.05)	$ (14.50)	$ (13.25)
Pension and other postretirement benefit plans obligations, tax	$ 7	$ 0	$ 2
PG&E Corporation | Administrative service revenue
Revenue	$ 127	$ 138	$ 90