Note 3 - Regulated Operations (Details) - Costs Related to Remediation of Former Operating Sites (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Environmental Exit Cost [Line Items]
Probabilistic model cost estimates, low estimate	$ 378
Probabilistic model cost estimates, high estimate	806
Engineering estimates	67
Amount recorded	440
Expected costs over next 12 months	82
Illinois Environmental [Member]
Environmental Exit Cost [Line Items]
Probabilistic model cost estimates, low estimate	211
Probabilistic model cost estimates, high estimate	461
Engineering estimates	42
Amount recorded	246
Expected costs over next 12 months	39
New Jersey Environmental [Member]
Environmental Exit Cost [Line Items]
Probabilistic model cost estimates, low estimate	139
Probabilistic model cost estimates, high estimate	233
Engineering estimates	6
Amount recorded	144
Expected costs over next 12 months	25
Georgia And Florida [Member]
Environmental Exit Cost [Line Items]
Probabilistic model cost estimates, low estimate	28
Probabilistic model cost estimates, high estimate	112
Engineering estimates	8
Amount recorded	39
Expected costs over next 12 months	10
North Carolina Environmental [Member]
Environmental Exit Cost [Line Items]
Probabilistic model cost estimates, low estimate
Probabilistic model cost estimates, high estimate
Engineering estimates	11
Amount recorded	11
Expected costs over next 12 months	$ 8