Property, Plant and Equipment (tables)

3 Months Ended

Mar. 31, 2012

Public Utilities Property Plant And Equipment Abstract

Major Classifications Of Property, Plant And Equipment And Accumulated Depreciation [Text Block]

		March 31,				December 31,
Thousands		2012		2011		2011
Utility plant in service		$	2,342,681	$	2,264,055	$	2,323,467
Utility construction work in progress			34,903		28,464		36,051
Less: Accumulated depreciation			760,566		720,134		749,603
	Utility plant-net		1,617,018		1,572,385		1,609,915
Non-utility plant in service			297,164		292,089		293,205
Non-utility construction work in progress			5,789		8,945		8,379
Less: Accumulated depreciation			19,117		13,505		17,623
	Non-utility plant-net	$	283,836	$	287,529	$	283,961
Total property, plant and equipment		$	1,900,854	$	1,859,914	$	1,893,876