REGULATED OPERATING EXPENSE (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
REGULATED OPERATING EXPENSE
Power operation expense (other than fuel)	$ 15,643	$ 15,045	$ 12,685
Electric transmission and distribution expense	21,863	17,083	15,361
Natural gas transmission and distribution expense	2,498	2,443	2,385
Customer accounts and assistance expense	11,180	10,211	10,210
Employee pension expense	10,736	10,180	8,805
Employee healthcare plan	10,190	9,825	7,439
General office supplies and expense	12,850	10,776	10,158
Administrative and general expense	14,800	15,091	14,295
Bad debt expense	3,665	3,038	3,425
Regulatory reversal of gain on sale of assets	1,236
Miscellaneous expense	672	679	679
Total	$ 105,333	$ 94,371	$ 85,442