Note 10 - Non-wholly Owned Entities (Details) - SouthStar’s Assets and Liabilities (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Current assets	$ 2,890		$ 2,895
Goodwill and other intangible assets	1,952		1,972
Long-term assets and other deferred debits	10,067		9,683
Total assets	14,909		14,550
Current liabilities	3,219		3,118
Long-term liabilities and other deferred credits	7,862		7,819
Total liabilities	11,081		10,937
Equity	3,828		3,613		3,391	3,305
Total liabilities and equity	14,909		14,550
South Star [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Current assets	238	[1]	264	[1]
Goodwill and other intangible assets	125	[1]	133	[1]
Long-term assets and other deferred debits	17	[1]	13	[1]
Total assets	380	[1]	410	[1]
Current liabilities	71	[1]	95	[1]
Long-term liabilities and other deferred credits		[1]		[1]
Total liabilities	71	[1]	95	[1]
Equity	309	[1]	315	[1]
Total liabilities and equity	$ 380	[1]	$ 410	[1]
South Star Percentage To Consolidated [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Current assets	8.00%	[2]	9.00%	[2]
Goodwill and other intangible assets	6.00%	[2]	7.00%	[2]
Long-term assets and other deferred debits		[2]		[2]
Total assets	3.00%	[2]	3.00%	[2]
Current liabilities	2.00%	[2]	3.00%	[2]
Long-term liabilities and other deferred credits		[2]		[2]
Total liabilities	1.00%	[2]	1.00%	[2]
Equity	8.00%	[2]	9.00%	[2]
Total liabilities and equity	3.00%	[2]	3.00%	[2]

[1] These amounts reflect information for SouthStar and exclude intercompany eliminations and the balances of our wholly owned subsidiary with an 85% ownership interest in SouthStar.

[2] SouthStar's percentage of the amount on our Consolidated Statements of Financial Position.