Consolidation and Nature of Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Operating Revenues
Regulated electricity segment		$ 1,124,057
OPERATING REVENUES	1,109,475	1,124,841	2,608,682	2,573,487
Cash Flows from Investing Activities
Other			(520)	(1,246)
As previously reported
Operating Revenues
Regulated electricity segment		1,124,049		2,570,692
Other revenues		792		2,795
Cash Flows from Investing Activities
Proceeds from sale of commercial real estate investments				1,100
Other				(2,346)
Reclassifications to conform to current year presentation
Operating Revenues
Regulated electricity segment		(1,124,049)		(2,570,692)
Other revenues		(792)		(2,795)
OPERATING REVENUES		1,124,841		2,573,487
Cash Flows from Investing Activities
Proceeds from sale of commercial real estate investments				(1,100)
Other				1,100
Amount reported after reclassifications to conform to current year presentation
Operating Revenues
OPERATING REVENUES		1,124,841		2,573,487
Cash Flows from Investing Activities
Other				$ (1,246)