CONSOLIDATED BALANCE SHEET (Parenthetical) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Accounts receivable - customers, allowance for uncollectible accounts	$ 94	$ 94
Other receivables, allowance for uncollectible accounts	10	10
Non-utility property, accumulated depreciation	73	68
Intangible assets, accumulated amortization	4	4
CECONY [Member]
Accounts receivable - customers, allowance for uncollectible accounts	87	87
Other receivables, allowance for uncollectible accounts	8	9
Non-utility property, accumulated depreciation	$ 25	$ 25