Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant (Tables)

12 Months Ended

Dec. 31, 2011

Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant [Abstract]

Schedule of Property, Plant and Equipment and Finite-Lived Intangible Assets By Major Class

The table below presents the balance of each major class of depreciable assets at December 31, 2011 (in thousands):

	Gross Plant		Accumulated Depreciation			Net Plant
Nuclear production	$	768,284	$	(240,862	)	$	527,422
Steam and other	557,286		(223,109		)	334,177
Total production	1,325,570		(463,971		)	861,599
Transmission	394,385		(238,940		)	155,445
Distribution	864,746		(308,644		)	556,102
General	141,921		(78,323		)	63,598
Intangible	63,151		(31,775		)	31,376
Total	$	2,789,773	$	(1,121,653	)	$	1,668,120

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The table below presents the actual and estimated amortization expense for intangible plant for the previous three years and for the next five years (in thousands):

2009	$	4,542
2010	6,312
2011	6,668
2012 (estimated)	6,124
2013 (estimated)	5,403
2014 (estimated)	4,292
2015 (estimated)	3,542
2016 (estimated)	3,045

Schedule of Jointly Owned Utility Plants

A summary of the Company’s investment in jointly-owned utility plant, excluding fuel inventories, at December 31, 2011 and 2010 is as follows (in thousands):

	December 31, 2011						December 31, 2010
	Palo Verde			Other			Palo Verde			Other
Electric plant in service	$	768,284		$	211,983		$	772,710		$	209,427
Accumulated depreciation	(240,862		)	(164,622		)	(225,461		)	(159,679		)
Construction work in progress	53,822			1,634			48,703			1,940
Total	$	581,244		$	48,995		$	595,952		$	51,688