Note 9 - Non-Wholly Owned Entities (Details) - SouthStar’s Revenues and Expenses (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Variable Interest Entity [Line Items]
Operating revenues	$ 2,462	[1]	$ 1,612	[1]
Operating income	592	[1]	290	[1]
Cost of goods sold	1,400	[1]	920	[1]
Operation and maintenance	289	[1]	231	[1]
Depreciation and amortization	93	[1]	102	[1]
Total operating expenses	1,870	[1]	1,322	[1]
South Star [Member]
Variable Interest Entity [Line Items]
Operating revenues	374	[1]	250	[1]
Operating income	78	[1]	67	[1]
Cost of goods sold	270	[1]	164	[1]
Operation and maintenance	23	[1]	18	[1]
Depreciation and amortization	3	[1]	1	[1]
Total operating expenses	$ 296	[1]	$ 183	[1]

[1] Amounts revised to include prior period adjustments. See Note 13 for additional information.