Variable Interest Entities (VIEs) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Operating Revenues	$ 3,135	$ 3,223
Operation and Maintenance	663	856
PSE And G [Member]
Maximum exposure to loss	16		16
Operating Revenues	2,002	2,145
Operation and Maintenance	412	462
Long Island ServCo [Member]
Operating Revenues	82	89
Operation and Maintenance	$ 82	$ 89