Consolidated Balance Sheet (Parenthetical) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Accounts receivable - customers, allowance for uncollectible accounts	$ 86	$ 87
Other receivables, allowance for uncollectible accounts	10	10
Non-utility property, accumulated depreciation	64	59
Intangible assets, accumulated amortization	4	3
CECONY
Accounts receivable - customers, allowance for uncollectible accounts	79	79
Other receivables, allowance for uncollectible accounts	9	9
Non-utility property, accumulated depreciation	$ 24	$ 24