Note 8 - Non-Wholly Owned Entities (Detail) - Variable Interest Entities (USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011		Mar. 31, 2011		Dec. 31, 2010
Current assets (in Dollars)	$ 2,022		$ 2,746		$ 1,587
Long-term assets and other deferred debits (in Dollars)	11,217		11,167		5,439
Total assets (in Dollars)	13,239	[1]	13,913	[2]	7,026	[1]
Current liabilities (in Dollars)	2,348		3,084		1,313
Long-term liabilities and other deferred credits (in Dollars)	7,465		7,490		3,793
Total Liabilities (in Dollars)	9,813		10,574		5,106
Equity (in Dollars)	3,426		3,339		1,920		1,836
Total liabilities and equity (in Dollars)	13,239		13,913		7,026
South Star [Member]
Current assets (in Dollars)	149	[3]	210	[3]	170	[3]
Long-term assets and other deferred debits (in Dollars)	9	[3]	9	[3]	9	[3]
Total assets (in Dollars)	158	[3]	219	[3]	179	[3]
Current liabilities (in Dollars)	52	[3]	77	[3]	61	[3]
Long-term liabilities and other deferred credits (in Dollars)	0	[3]	0	[3]	0	[3]
Total Liabilities (in Dollars)	52	[3]	77	[3]	61	[3]
Equity (in Dollars)	106	[3]	142	[3]	118	[3]
Total liabilities and equity (in Dollars)	$ 158	[3]	$ 219	[3]	$ 179	[3]
South Star Percentage To Consolidated [Member]
Current assets	7.00%	[4]	8.00%	[4]	11.00%	[4]
Long-term assets and other deferred debits	0.00%	[4]	0.00%	[4]	0.00%	[4]
Total assets	1.00%	[4]	2.00%	[4]	3.00%	[4]
Current liabilities	2.00%	[4]	2.00%	[4]	5.00%	[4]
Long-term liabilities and other deferred credits	0.00%	[4]	0.00%	[4]	0.00%	[4]
Total Liabilities	1.00%	[4]	1.00%	[4]	1.00%	[4]
Equity	3.00%	[4]	4.00%	[4]	6.00%	[4]
Total liabilities and equity	1.00%	[4]	2.00%	[4]	3.00%	[4]

[1] Identifiable assets are those used in each segment's operations.

[2] Identifiable assets are those assets used in each segment's operations.

[3] These amounts reflect information for SouthStar and do not include intercompany eliminations and the balances of our wholly owned subsidiary with an 85% ownership interest in SouthStar.

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