Selected Balance Sheet Data

12 Months Ended

Dec. 31, 2014

Balance Sheet Related Disclosures [Abstract]

Selected Balance Sheet Data

Selected Balance Sheet Data

(Thousands of Dollars)	Dec. 31, 2014		Dec. 31, 2013
Accounts receivable, net (a)
Accounts receivable	66,217		64,180
Less allowance for bad debts	(5,821	)	(4,911	)
	60,396		59,269

^(a)  Accounts receivable, net includes an immaterial amount and $1,595 due from affiliates for 2014 and 2013, respectively.

(Thousands of Dollars)	Dec. 31, 2014		Dec. 31, 2013
Inventories
Materials and supplies	$	6,494	$	6,437
Fuel	6,654		5,915
Natural gas	11,537		9,123
	$	24,685	$	21,475

(Thousands of Dollars)	Dec. 31, 2014			Dec. 31, 2013
Property, plant and equipment, net
Electric plant	$	2,061,669		$	1,913,354
Natural gas plant	255,465			236,047
Common and other property	125,938			112,886
CWIP	231,413			127,954
Total property, plant and equipment	2,674,485			2,390,241
Less accumulated depreciation	(1,000,204		)	(947,462		)
	$	1,674,281		$	1,442,779