Selected Balance Sheet Data

9 Months Ended

Sep. 30, 2011

Selected Balance Sheet Data [Abstract]

Selected Balance Sheet Data

3. Selected Balance Sheet Data

(Thousands of Dollars)	Sept. 30, 2011			Dec. 31, 2010
Accounts receivable, net (a)
Accounts receivable	$	54,050		$	55,929
Less allowance for bad debts		(4,333	)		(4,262	)
	$	49,717		$	51,667
Inventories
Materials and supplies	$	5,884		$	5,564
Fuel		9,471			10,819
Natural gas		12,470			10,233
	$	27,825		$	26,616
Property, plant and equipment, net
Electric plant	$	1,649,193		$	1,590,713
Natural gas plant		206,149			199,224
Common and other property		111,672			123,793
Construction work in progress		50,974			42,874
Total property, plant and equipment		2,017,988			1,956,604
Less accumulated depreciation		(845,986	)		(826,262	)
	$	1,172,002		$	1,130,342

(a)Accounts receivable, net includes $2,000 and $3,000 due from affiliates, as of Sept. 30, 2011 and Dec. 31, 2010, respectively.