Note 9 - Non-Wholly Owned Entities (Details) - SouthStar’s Assets and Liabilities - USD ($) $ in Millions		Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Current assets		$ 1,572	$ 2,886	$ 2,380
Goodwill and other intangible assets		1,939	1,952	1,962
Long-term assets and other deferred debits		10,324	10,050	9,817
Total assets		13,835	14,888	14,159
Current liabilities		2,047	3,219	2,595
Long-term liabilities and other deferred credits		7,799	7,841	7,704
Total Liabilities		9,846	11,060	10,299
Equity		3,989	3,828	3,860	$ 3,613
Total liabilities and equity		13,835	14,888	14,159
South Star [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Current assets	[1]	192	236	195
Goodwill and other intangible assets	[1]	117	125	129
Long-term assets and other deferred debits	[1]	17	17	17
Total assets	[1]	326	378	341
Current liabilities	[1]	40	$ 71	$ 55
Long-term liabilities and other deferred credits	[1]	1
Total Liabilities	[1]	41	$ 71	$ 55
Equity	[1]	285	307	286
Total liabilities and equity	[1]	$ 326	$ 378	$ 341
South Star Percentage To Consolidated [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Current assets		12.00%	8.00%	8.00%
Goodwill and other intangible assets		6.00%	6.00%	7.00%
Total assets		2.00%	3.00%	2.00%
Current liabilities		2.00%	2.00%	2.00%
Long-term liabilities and other deferred credits		0.00%	0.00%	0.00%
Total Liabilities			1.00%	1.00%
Equity		7.00%	8.00%	7.00%
Total liabilities and equity		2.00%	3.00%	2.00%

[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.