CONDENSED STATEMENTS OF CONSOLIDATED INCOME (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Income Statement [Abstract]
Revenues	$ 1,550	$ 2,095
Expenses:
Natural gas	969	1,476
Operation and maintenance	239	240
Depreciation and amortization	69	66
Taxes other than income taxes	44	53
Total	1,321	1,835
Operating Income	229	260
Other Income (Expense):
Interest and other finance charges	(45)	(49)
Equity in earnings of unconsolidated affiliates	9	6
Other, net	0	1
Total	(36)	(42)
Income Before Income Taxes	193	218
Income tax expense	75	85
Net Income	$ 118	$ 133