Consolidated Balance Sheet (Parenthetical) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Accounts receivable - customers, allowance for uncollectible accounts	$ 96	$ 93
Other receivables, allowance for uncollectible accounts	10	10
Non-utility property, accumulated depreciation	97	90
Intangible assets, accumulated amortization	4	4
CECONY [Member]
Accounts receivable - customers, allowance for uncollectible accounts	90	87
Other receivables, allowance for uncollectible accounts	9	8
Non-utility property, accumulated depreciation	$ 25	$ 25