Note 2 - Significant Accounting Policies and Methods of Application (Detail) - Estimated Useful Lives of Assets	12 Months Ended
	Dec. 31, 2012
Gas, Transmission and Distribution Equipment [Member] | Minimum [Member]
Depreciable Property	5
Gas, Transmission and Distribution Equipment [Member] | Maximum [Member]
Depreciable Property	10
Gas, Transmission and Distribution Equipment [Member]
Depreciable Property	-
Cargo Shipping Vessels [Member] | Minimum [Member]
Depreciable Property	20
Cargo Shipping Vessels [Member] | Maximum [Member]
Depreciable Property	25
Cargo Shipping Vessels [Member]
Depreciable Property	-
Storage [Member] | Minimum [Member]
Depreciable Property	40
Storage [Member] | Maximum [Member]
Depreciable Property	60
Storage [Member]
Depreciable Property	-
Property, Plant and Equipment, Other Types [Member]
Depreciable Property	up to 40