SEGMENTS OF BUSINESS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Operating revenues	$ 121,913	$ 160,477	$ 396,745	$ 492,399
Operating income (loss)	10,257	12,439	83,765	85,486
Depreciation and amortization	14,188	11,819	27,463	23,420
Interest charges	5,195	6,234	10,688	12,215
Income taxes	(1,072)	3,004	14,812	25,514
Property additions	47,239	47,471	93,654	74,933
Indentifiable assets	2,325,991		2,325,991		2,247,510
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	129,936	169,049	413,290	514,966
Interest charges	5,908	7,157	11,961	13,767
Operating Segments [Member] | Gas Utility Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	59,177	65,187	238,613	245,510
Operating income (loss)	7,465	7,065	66,320	65,558
Depreciation and amortization	11,130	10,375	22,092	20,678
Interest charges	3,771	4,895	7,960	9,924
Income taxes	1,887	1,065	22,864	23,111
Property additions	40,220	38,638	80,876	59,076
Indentifiable assets	1,659,006		1,659,006		1,615,723
Operating Segments [Member] | Wholesale Energy Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	(471)	6,475	17,171	54,746
Operating income (loss)	(2,843)	1,438	7,829	11,095
Depreciation and amortization	64	68	117	134
Interest charges	72	9	158	22
Income taxes	(1,028)	858	2,953	5,020
Property additions	8	6	12	30
Indentifiable assets	134,410		134,410		159,424
Operating Segments [Member] | Retail Energy Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	64,899	91,317	144,461	202,676
Operating income (loss)	5,621	3,960	9,634	9,100
Depreciation and amortization	2,823	1,198	4,919	2,269
Interest charges	1,228	1,564	2,285	2,637
Income taxes	(1,950)	1,011	(11,083)	(2,691)
Property additions	5,757	8,724	11,107	15,445
Indentifiable assets	300,329		300,329		332,272
Operating Segments [Member] | Retail Energy Operations [Member] | Retail Gas and Other Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	13,600	23,042	31,792	60,284
Operating income (loss)	(395)	(59)	(547)	714
Depreciation and amortization	23	10	31	17
Interest charges	13	51	51	111
Income taxes	(90)	24	94	538
Property additions	50	2	103	15
Indentifiable assets	17,054		17,054		14,659
Operating Segments [Member] | Retail Energy Operations [Member] | Retail Electric Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	38,365	54,258	88,552	114,153
Operating income (loss)	5,110	2,978	10,054	6,841
Income taxes	2,087	1,217	4,107	2,795
Indentifiable assets	22,261		22,261		31,225
Operating Segments [Member] | Retail Energy Operations [Member] | On-site Energy Production [Member]
Segment Reporting Information [Line Items]
Operating revenues	9,356	9,863	17,257	19,651
Operating income (loss)	684	1,273	346	2,367
Depreciation and amortization	2,722	1,113	4,726	2,103
Interest charges	1,215	1,513	2,234	2,526
Income taxes	(4,056)	(864)	(15,230)	(7,657)
Property additions	5,705	8,590	11,002	15,297
Indentifiable assets	252,612		252,612		275,053
Operating Segments [Member] | Retail Energy Operations [Member] | Appliance Service Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	3,578	4,154	6,860	8,588
Operating income (loss)	222	(232)	(219)	(822)
Depreciation and amortization	78	75	162	149
Income taxes	109	634	(54)	1,633
Property additions	2	132	2	133
Indentifiable assets	8,402		8,402		11,335
Operating Segments [Member] | Corporate and Services [Member]
Segment Reporting Information [Line Items]
Operating revenues	6,331	6,070	13,045	12,034
Operating income (loss)	14	(24)	(18)	(267)
Depreciation and amortization	171	178	335	339
Interest charges	837	689	1,558	1,184
Income taxes	19	70	78	74
Property additions	1,254	103	1,659	382
Indentifiable assets	242,540		242,540		156,252
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Operating revenues	(8,023)	(8,572)	(16,545)	(22,567)
Interest charges	(713)	(923)	(1,273)	(1,552)
Indentifiable assets	(10,390)		(10,390)		(16,385)
Segment, Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Indentifiable assets	$ 96		$ 96		$ 224