REGULATED OPERATING EXPENSE (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
REGULATED OPERATING EXPENSE
Power operation expense (other than fuel)	$ 13,277	$ 11,356	$ 12,315
Electric transmission and distribution expense	15,361	12,996	11,063
Natural gas transmission and distribution expense	2,385	2,194	2,161
Customer accounts & assistance expense	10,210	11,618	10,597
Employee pension expense	8,805	5,899	5,557
Employee healthcare plan	7,439	6,930	5,908
General office supplies and expense	10,158	11,584	10,070
Administrative and general expense	14,295	12,896	12,211
Bad debt expense	3,425	3,651	3,125
Miscellaneous expense	87	168	79
TOTAL	$ 85,442	$ 79,292	$ 73,086