Note 9 - Non-Wholly Owned Entities (Details) - SouthStar’s Revenues and Expenses (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Variable Interest Entity [Line Items]
Operating revenues	$ 889	[1]	$ 805	[1]	$ 3,351	[1]	$ 2,417	[1]
Operating income	139	[1]	113	[1]	731	[1]	403	[1]
Cost of goods sold	402	[1]	353	[1]	1,802	[1]	1,273	[1]
Operation and maintenance	211	[1]	204	[1]	500	[1]	435	[1]
Depreciation and amortization	95	[1]	103	[1]	188	[1]	205	[1]
Taxes other than income taxes	42	[1]	43	[1]	130	[1]	112	[1]
Total operating expenses	750	[1]	703	[1]	2,620	[1]	2,025	[1]
South Star [Member]
Variable Interest Entity [Line Items]
Operating revenues	145		116		519		366
Operating income	11		5		89		72
Cost of goods sold	111		95		381		259
Operation and maintenance	20		15		43		33
Depreciation and amortization	2				5		1
Taxes other than income taxes	1		1		1		1
Total operating expenses	$ 134		$ 111		$ 430		$ 294

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