Selected Balance Sheet Data

6 Months Ended

Jun. 30, 2012

Selected Balance Sheet Data [Abstract]

3.	Selected Balance Sheet Data

(Thousands of Dollars)	June 30, 2012			Dec. 31, 2011
Accounts receivable, net
Accounts receivable	$	698,853		$	811,685
Less allowance for bad debts		(53,589	)		(58,565	)
	$	645,264		$	753,120
Inventories
Materials and supplies	$	210,197		$	202,699
Fuel		182,281			236,023
Natural gas		80,659			179,510
	$	473,137		$	618,232
Property, plant and equipment, net
Electric plant	$	27,717,392		$	27,254,541
Natural gas plant		3,735,411			3,676,754
Common and other property		1,454,246			1,546,643
Plant to be retired (a)		112,823			151,184
Construction work in progress		1,484,593			1,085,245
Total property, plant and equipment		34,504,465			33,714,367
Less accumulated depreciation		(11,852,561	)		(11,658,351	)
Nuclear fuel		2,087,663			1,939,299
Less accumulated amortization		(1,691,713	)		(1,641,948	)
	$	23,047,854		$	22,353,367

(a)

In 2010, in response to the Clean Air Clean Jobs Act (CACJA), the Colorado Public Utilities Commission (CPUC) approved the early retirement of Cherokee Units 1, 2 and 3, Arapahoe Unit 3 and Valmont Unit 5 between 2011 and 2017. In 2011, Cherokee Unit 2 was retired and in May 2012, Cherokee Unit 1 was retired. Amounts are presented net of accumulated depreciation.