Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment
Regulated energy	$ 590,816	$ 585,429
Unregulated energy	71,787	70,218
Other	20,449	20,067
Total property, plant and equipment	683,052	675,714
Less: Accumulated depreciation and amortization	(160,199)	(155,378)
Plus: Construction work in progress	29,880	21,445
Net property, plant and equipment	552,733	541,781
Current Assets
Cash and cash equivalents	2,608	3,361
Accounts receivable (less allowance for uncollectible accounts of $1,008 and $826, respectively)	62,891	53,787
Accrued revenue	11,241	11,688
Propane inventory, at average cost	5,614	7,612
Other inventory, at average cost	3,199	5,841
Regulatory assets	1,881	2,736
Storage gas prepayments	897	3,716
Income taxes receivable		4,703
Deferred income taxes	836	791
Prepaid expenses	4,452	6,020
Mark-to-market energy assets	150	210
Other current assets	146	132
Total current assets	93,915	100,597
Deferred Charges and Other Assets
Goodwill	4,543	4,090
Other intangible assets, net	3,017	2,798
Investments, at fair value	4,526	4,168
Regulatory assets	76,360	77,408
Receivables and other deferred charges	3,363	2,904
Total deferred charges and other assets	91,809	91,368
Total Assets	738,457	733,746
Stockholders' equity
Common stock, par value $0.4867 per share (authorized 25,000,000 shares)	4,679	4,671
Additional paid-in capital	150,527	150,750
Retained earnings	117,579	106,239
Accumulated other comprehensive loss	(5,013)	(5,062)
Deferred compensation obligation	994	982
Treasury stock	(994)	(982)
Total stockholders' equity	267,772	256,598
Long-term debt, net of current maturities	100,952	101,907
Total capitalization	368,724	358,505
Current Liabilities
Current portion of long-term debt	9,093	8,196
Short-term borrowing	47,635	61,199
Accounts payable	38,835	41,992
Customer deposits and refunds	26,788	29,271
Accrued interest	2,622	1,437
Dividends payable	3,504	3,502
Income taxes payable	4,196
Accrued compensation	4,708	7,435
Regulatory liabilities	7,576	1,577
Mark-to-market energy liabilities	85	331
Other accrued liabilities	8,643	7,226
Total current liabilities	153,685	162,166
Deferred Credits and Other Liabilities
Deferred income taxes	127,491	125,205
Deferred investment tax credits	103	113
Regulatory liabilities	5,336	5,454
Environmental liabilities	9,094	9,114
Other pension and benefit costs	33,890	33,535
Accrued asset removal cost-Regulatory liability	38,554	38,096
Other liabilities	1,580	1,558
Total deferred credits and other liabilities	216,048	213,075
Other commitments and contingencies (Note 5 and 6)
Total Capitalization and Liabilities	$ 738,457	$ 733,746