CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 4,459		$ 1,571
Accounts receivable, net	50,706	[1]	51,838
Accrued unbilled revenues	49,138		48,668
Inventories	19,685		25,703
Regulatory assets	12,048		14,133
Prepaid taxes	24,688		21,841
Prepayments and other	4,394		2,991
Total current assets	165,118		166,745
Property, plant and equipment, net	1,298,236		1,207,698
Other assets
Regulatory assets, non-current	240,459		229,910
Other investments	3,232		4,148
Other	4,040		2,970
Total other assets	247,731		237,028
Total assets	1,711,085		1,611,471
Current liabilities
Current portion of long-term debt	1,246		1,286
Short-term debt	39,000		66,000
Notes payable to affiliates	550		500
Accounts payable	30,723		30,897
Accounts payable to affiliates	31,556		23,285
Dividends payable to parent	7,667		8,107
Regulatory liabilities	6,086		16,609
Environmental liabilities	23,427		30,699
Accrued interest	7,304		6,521
Other	11,794		13,907
Total current liabilities	159,353		197,811
Deferred credits and other liabilities
Deferred income taxes	261,800		234,222
Deferred investment tax credits	8,911		8,499
Regulatory liabilities	123,746		119,187
Environmental liabilities	84,655		79,399
Customer advances	15,631		15,765
Pension and employee benefit obligations	63,643		60,328
Other	8,923		7,024
Total deferred credits and other liabilities	567,309		524,424
Commitments and contingencies
Capitalization
Long-term debt	467,317		368,083
Common stock - 1,000,000 shares authorized of $100 par value; 933,000 shares outstanding at Dec. 31, 2012 and 2011, respectively .	93,300		93,300
Additional paid in capital	189,867		187,071
Retained earnings	234,376		241,296
Accumulated other comprehensive loss	(437)		(514)
Total common stockholder's equity	517,106		521,153
Total liabilities and equity	$ 1,711,085		$ 1,611,471

[1] Accounts receivable, net includes $586 due from affiliates as of Dec. 31, 2012.