Selected Balance Sheet Data

6 Months Ended

Jun. 30, 2011

Selected Balance Sheet Data [Abstract]

Selected Balance Sheet Data

3. Selected Balance Sheet Data

(Thousands of Dollars)	June 30, 2011			Dec. 31, 2010
Accounts receivable, net (a)
Accounts receivable	$	51,606		$	55,929
Less allowance for bad debts		(3,968	)		(4,262	)
	$	47,638		$	51,667
Inventories
Materials and supplies	$	5,807		$	5,564
Fuel		10,268			10,819
Natural gas		4,737			10,233
	$	20,812		$	26,616
Property, plant and equipment, net
Electric plant	$	1,633,630		$	1,590,713
Natural gas plant		203,046			199,224
Common and other property		128,044			123,793
Construction work in progress		41,312			42,874
Total property, plant and equipment		2,006,032			1,956,604
Less accumulated depreciation		(852,969	)		(826,262	)
	$	1,153,063		$	1,130,342

(a)Accounts receivable, net includes $1 million and $3 million due from affiliates, as of June 30, 2011 and Dec. 31, 2010, respectively.