Note 19 - Business Segments (Details) - Revenue From Major Customers (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Revenue, Major Customer [Line Items]
Revenues (in Dollars)	$ 533,239	[1]	$ 501,773	[1]	$ 425,456	[1]
Southern California Edison Company [Member]
Revenue, Major Customer [Line Items]
Revenues (in Dollars)	75,562	[2]	90,239	[2]	121,049	[2]
Percentage of Revenues	14.20%	[2]	18.00%	[2]	28.50%	[2]
Hawaii Electric Light Company [Member]
Revenue, Major Customer [Line Items]
Revenues (in Dollars)	48,825	[2]	48,606	[2]	46,432	[2]
Percentage of Revenues	9.20%	[2]	9.70%	[2]	10.90%	[2]
Sierra Pacific Power Company And Nevada Power Company [Member]
Revenue, Major Customer [Line Items]
Revenues (in Dollars)	94,111	[2],[3]	78,631	[2],[3]	56,778	[2],[3]
Percentage of Revenues	17.60%	[2],[3]	15.70%	[2],[3]	13.30%	[2],[3]
Mighty River Power Limited [Member]
Revenue, Major Customer [Line Items]
Revenues (in Dollars)	19,174	[4]	99,617	[4]	19,956	[4]
Percentage of Revenues	3.60%	[4]	19.90%	[4]	4.70%	[4]
KPLC [Member]
Revenue, Major Customer [Line Items]
Revenues (in Dollars)	$ 61,876	[2]	$ 40,887	[2]	$ 35,179	[2]
Percentage of Revenues	11.60%	[2]	8.10%	[2]	8.30%	[2]

[1] Revenues as reported in the geographic area in which they originate.

[2] Revenues reported in Electricity Segment.

[3] Subsidiaries of NV Energy, Inc.

[4] Revenues reported in Products Segment.