CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents		$ 1,021	$ 1,079
Accounts receivable, net	[1]	47,811	56,378
Accrued unbilled revenues		39,495	47,698
Inventories		20,269	21,559
Regulatory assets		13,567	16,146
Prepaid taxes		17,495	25,976
Deferred income taxes		7,671	3,138
Prepayments and other		3,187	2,387
Total current assets		150,516	174,361
Property, plant and equipment, net		1,901,696	1,828,079
Other assets
Regulatory assets		292,969	289,196
Other investments		3,259	4,042
Other		471	67
Total other assets		296,699	293,305
Total assets		2,348,911	2,295,745
Current liabilities
Current portion of long-term debt		1,138	1,131
Short-term debt		4,000	10,000
Notes payable to affiliates		500	500
Accounts payable		38,153	34,317
Accounts payable to affiliates		30,386	24,538
Dividends payable to parent		14,687	15,322
Regulatory liabilities		17,546	11,781
Environmental liabilities		16,366	17,155
Accrued interest		9,615	7,945
Other		13,226	15,778
Total current liabilities		145,617	138,467
Deferred credits and other liabilities
Deferred income taxes		428,051	393,569
Deferred investment tax credits		8,164	8,560
Regulatory liabilities		146,247	141,289
Environmental liabilities		68,419	77,441
Customer advances		19,678	18,480
Pension and employee benefit obligations		43,461	49,889
Other		16,858	16,347
Total deferred credits and other liabilities		730,878	705,575
Commitments and contingencies
Capitalization
Long-term debt		661,796	661,318
Common stock — 1,000,000 shares authorized of $100 par value; 933,000 shares outstanding at Sept. 30, 2016 and Dec. 31, 2015, respectively		93,300	93,300
Additional paid in capital		398,033	394,553
Retained earnings		319,439	302,741
Accumulated other comprehensive loss		(152)	(209)
Total common stockholder’s equity		810,620	790,385
Total liabilities and equity		$ 2,348,911	$ 2,295,745

[1] Accounts receivable, net includes an immaterial amount due from affiliates as of Sept. 30, 2016 and Dec. 31, 2015, respectively.