Selected Balance Sheet Data

3 Months Ended

Mar. 31, 2020

Balance Sheet Related Disclosures [Abstract]

Selected Balance Sheet Data

(Millions of Dollars)	March 31, 2020			Dec. 31, 2019
Accounts receivable, net
Accounts receivable	$	70.0		$	64.7
Less allowance for bad debts	(6.0		)	(5.5		)
Accounts receivable, net	$	64.0		$	59.2

(Millions of Dollars)	March 31, 2020		Dec. 31, 2019
Inventories
Materials and supplies	$	7.1	$	6.8
Fuel	4.1		4.0
Natural gas	1.0		5.2
Total inventories	$	12.2	$	16.0

(Millions of Dollars)	March 31, 2020			Dec. 31, 2019
Property, plant and equipment, net
Electric plant	$	3,048.0		$	3,024.6
Natural gas plant	370.4			365.5
Common and other property	205.4			201.5
Construction work in progress	94.8			82.8
Total property, plant and equipment	3,718.6			3,674.4
Less accumulated depreciation	(1,335.9		)	(1,315.0		)
Property, plant and equipment, net	$	2,382.7		$	2,359.4