CONSOLIDATED BALANCE SHEETS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 1,495		$ 1,571
Accounts receivable, net	49,454	[1]	51,838
Accrued unbilled revenues	39,172		48,668
Inventories	21,779		25,703
Regulatory assets	10,698		14,133
Prepaid taxes	16,074		21,841
Deferred income taxes	8,855		0
Prepayments and other	2,660		2,991
Total current assets	150,187		166,745
Property, plant and equipment, net	1,264,084		1,207,698
Other assets
Regulatory assets	228,334		229,910
Other investments	3,052		4,148
Other	2,964		2,970
Total other assets	234,350		237,028
Total assets	1,648,621		1,611,471
Current liabilities
Current portion of long-term debt	1,256		1,286
Short-term debt	99,000		66,000
Notes payable to affiliates	550		500
Accounts payable	24,258		30,897
Accounts payable to affiliates	22,056		23,285
Dividends payable to parent	8,005		8,107
Regulatory liabilities	6,673		16,609
Environmental liabilities	31,650		30,699
Accrued interest	5,565		6,521
Taxes accrued	8,656		1,238
Derivative instruments	0		2,514
Other	10,917		10,155
Total current liabilities	218,586		197,811
Deferred credits and other liabilities
Deferred income taxes	263,853		234,222
Deferred investment tax credits	8,930		8,499
Regulatory liabilities	121,976		119,187
Environmental liabilities	78,800		79,399
Customer advances	15,736		15,765
Pension and employee benefit obligations	49,222		60,328
Other	6,382		7,024
Total deferred credits and other liabilities	544,899		524,424
Commitments and contingencies
Capitalization
Long-term debt	368,147		368,083
Common stock - 1,000,000 shares authorized of $100 par value; 933,000 shares outstanding at Sept. 30, 2012 and Dec. 31, 2011, respectively	93,300		93,300
Additional paid in capital	189,233		187,071
Retained earnings	234,912		241,296
Accumulated other comprehensive loss	(456)		(514)
Total common stockholder's equity	516,989		521,153
Total liabilities and equity	$ 1,648,621		$ 1,611,471

[1] Accounts receivable, net includes $256 due from affiliates as of Sept. 30, 2012.