EARNINGS PER SHARE (Reconciliation Of PG&E Corporation's Income Available For Common Shareholders And Weighted Average Common Shares Outstanding For Calculating Diluted EPS) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Income available for common shareholders	$ 442	$ 576
Weighted average common shares outstanding, basic (in shares)	515	508
Employee share-based compensation (in shares)	1	3
Weighted average common shares outstanding, diluted (in shares)	516	511
Total earnings per common share, diluted (in dollars per share)	$ 0.86	$ 1.13