Property, Plant and Equipment (tables)

9 Months Ended

Sep. 30, 2012

Public Utilities, Property, Plant and Equipment [Abstract]

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

	September 30,				December 31,
Thousands	2012		2011		2011
Utility plant in service	$	2,399,600	$	2,296,788	$	2,323,467
Utility construction work in progress	53,017		36,459		36,051
Less: Accumulated depreciation	776,812		740,378		749,603
Utility plant-net	1,675,805		1,592,869		1,609,915
Non-utility plant in service	296,486		290,075		293,205
Non-utility construction work in progress	6,626		9,176		8,379
Less: Accumulated depreciation	21,698		16,214		17,623
Non-utility plant-net	281,414		283,037		283,961
Total property, plant and equipment	$	1,957,219	$	1,875,906	$	1,893,876