SEGMENTS OF BUSINESS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Operating revenues	$ 128,808	$ 111,977	$ 507,030	$ 508,722
Operating income (loss)	(5,206)	(55)	36,180	83,710
Depreciation and amortization	16,810	13,996	48,474	41,459
Interest charges	4,393	5,981	12,521	16,669
Income taxes	(5,533)	(2,576)	(9,393)	12,236
Property additions	102,884	50,359	204,151	144,013
Indentifiable assets	2,707,995		2,707,995		2,631,440
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	139,807	123,051	538,147	536,341
Interest charges	5,612	6,776	16,020	18,737
Operating Segments [Member] | Gas Utility Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	59,674	54,251	300,308	292,864
Operating income (loss)	3,285	2,950	69,149	69,270
Depreciation and amortization	12,476	11,209	36,429	33,301
Interest charges	2,629	3,872	8,379	11,832
Income taxes	471	258	23,511	23,122
Property additions	46,426	37,263	128,232	118,139
Indentifiable assets	1,857,187		1,857,187		1,786,459
Operating Segments [Member] | Wholesale Energy Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	128	(1,601)	(4,354)	15,570
Operating income (loss)	(8,969)	(4,380)	(33,326)	3,449
Depreciation and amortization	51	56	157	173
Interest charges	148	42	233	200
Income taxes	(3,616)	(1,673)	(13,307)	1,280
Property additions	8	1	42	13
Indentifiable assets	223,220		223,220		204,358
Operating Segments [Member] | Retail Energy Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	72,879	63,428	219,225	207,889
Operating income (loss)	372	1,036	247	10,670
Depreciation and amortization	4,076	2,561	11,235	7,480
Interest charges	1,347	1,513	3,200	3,798
Income taxes	(2,446)	(1,252)	(19,863)	(12,335)
Property additions	55,744	11,592	73,307	22,699
Indentifiable assets	589,594		589,594		608,060
Operating Segments [Member] | Retail Energy Operations [Member] | Retail Gas and Other Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	19,588	18,841	78,286	50,633
Operating income (loss)	(125)	(515)	(257)	(1,062)
Depreciation and amortization	21	18	64	49
Interest charges	73	49	216	100
Income taxes	(72)	(214)	148	(120)
Property additions	7	74	44	177
Indentifiable assets	32,451		32,451		39,481
Operating Segments [Member] | Retail Energy Operations [Member] | Retail Electric Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	36,063	28,918	98,211	117,470
Operating income (loss)	(146)	1,300	(19)	11,354
Income taxes	(59)	531	(8)	4,638
Indentifiable assets	23,468		23,468		21,919
Operating Segments [Member] | Retail Energy Operations [Member] | On-site Energy Production [Member]
Segment Reporting Information [Line Items]
Operating revenues	14,254	12,621	33,313	29,878
Operating income (loss)	111	440	(794)	786
Depreciation and amortization	4,008	2,469	10,978	7,195
Interest charges	1,274	1,464	2,984	3,698
Income taxes	(2,547)	(1,499)	(20,577)	(16,729)
Property additions	55,737	11,517	73,263	22,519
Indentifiable assets	531,202		531,202		543,416
Operating Segments [Member] | Retail Energy Operations [Member] | Appliance Service Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	2,974	3,048	9,415	9,908
Operating income (loss)	532	(189)	1,317	(408)
Depreciation and amortization	47	74	193	236
Income taxes	232	(70)	574	(124)
Property additions	0	1	0	3
Indentifiable assets	2,473		2,473		3,244
Operating Segments [Member] | Corporate and Services [Member]
Segment Reporting Information [Line Items]
Operating revenues	7,126	6,973	22,968	20,018
Operating income (loss)	106	339	110	321
Depreciation and amortization	207	170	653	505
Interest charges	1,488	1,349	4,208	2,907
Income taxes	58	91	266	169
Property additions	706	1,503	2,570	3,162
Indentifiable assets	323,886		323,886		337,010
Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Indentifiable assets	1,777		1,777		78
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Operating revenues	(10,999)	(11,074)	(31,117)	(27,619)
Interest charges	(1,219)	(795)	(3,499)	(2,068)
Indentifiable assets	$ (287,669)		$ (287,669)		$ (304,525)