Property, Plant and Equipment (tables)

12 Months Ended

Dec. 31, 2011

Public Utilities Property Plant And Equipment Abstract

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

Thousands		2011		2010
Utility plant in service		$	2,323,467	$	2,247,952
Utility construction work in progress			36,051		29,324
Less accumulated depreciation			749,603		710,214
	Utility plant-net		1,609,915		1,567,062
Non-utility plant in service			293,205		290,038
Non-utility construction work in progress			8,379		9,088
Less accumulated depreciation			17,623		12,025
	Non-utility plant-net		283,961		287,101
Total property plant and equipment		$	1,893,876	$	1,854,163