Note 3 - Regulated Operations (Details) - Change in Net Position of Deferred and Accrued Natural Gas Costs (USD $) In Millions, unless otherwise specified	3 Months Ended						12 Months Ended						12 Months Ended				12 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013		Mar. 31, 2014 Accrued natural gas costs [Member]		Dec. 31, 2013 Accrued natural gas costs [Member]		Mar. 31, 2013 Accrued natural gas costs [Member]		Mar. 31, 2014 Natural Gas Costs [Member]		Mar. 31, 2013 Natural Gas Costs [Member]		Mar. 31, 2014 Deferred Natural Gas Costs [Member]		Dec. 31, 2013 Deferred Natural Gas Costs [Member]		Mar. 31, 2013 Deferred Natural Gas Costs [Member]
Note 3 - Regulated Operations (Details) - Change in Net Position of Deferred and Accrued Natural Gas Costs [Line Items]
Deferred natural gas costs	$ 250	[1]	$ 72	[1]	$ 114	[1]											$ 161	[1]	$ 1	[1]		[1]
Deferred natural gas costs	228		(43)														161
Accrued natural gas costs	(161)	[1]	(238)	[1]	(183)	[1]	(24)	[1]	(92)	[1]	(133)	[1]
Accrued natural gas costs							109
Total (1)													137	[2]	(133)	[2]
Total (1)													$ 270	[2]

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

[2] The $270 million change resulted from increased natural gas prices during the first quarter of 2014 compared to the first quarter of 2013, primarily driven by colder weather experienced in the current quarter. These costs will be fully recovered in future periods.