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
Accounts receivable	$	84,562		$	49,966
Less allowance for bad debts		(5,164	)		(5,095	)
	$	79,398		$	44,871
Inventories
Materials and supplies	$	16,499		$	15,093
Fuel		18,082			14,756
	$	34,581		$	29,849
Property, plant and equipment, net
Electric plant	$	4,092,782		$	3,826,202
Construction work in progress		135,758			221,025
Total property, plant and equipment		4,228,540			4,047,227
Less accumulated depreciation		(1,696,086	)		(1,645,961	)
	$	2,532,454		$	2,401,266