Revenue Recognition (Tables)

3 Months Ended

Mar. 31, 2020

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue

The tables below reconcile revenue disaggregation by customer class to segment revenue as well as to revenues reflected on the Condensed Statements of Consolidated Income (unaudited) for the three months ended March 31, 2020 and March 31, 2019:

Three Months Ended March 31, 2020 (in millions)	Gas Distribution Operations		Electric Operations		Corporate and Other		Total
Customer Revenues(1)
Residential	$	796.5	$	119.2	$	—	$	915.7
Commercial	269.4		120.2		—		389.6
Industrial	74.2		109.1		—		183.3
Off-system	18.7		—		—		18.7
Miscellaneous	12.5		5.9		0.2		18.6
Total Customer Revenues	$	1,171.3	$	354.4	$	0.2	$	1,525.9
Other Revenues	56.7		22.9		—		79.6
Total Operating Revenues	$	1,228.0	$	377.3	$	0.2	$	1,605.5

⁽¹⁾ Customer revenue amounts exclude intersegment revenues. See Note 21, "Business Segment Information," for discussion of intersegment revenues.

Three Months Ended March 31, 2019 (in millions)	Gas Distribution Operations		Electric Operations		Corporate and Other		Total
Customer Revenues(1)
Residential	$	975.3	$	118.8	$	—	$	1,094.1
Commercial	330.5		119.3		—		449.8
Industrial	82.9		163.3		—		246.2
Off-system	20.1		—		—		20.1
Miscellaneous	17.2		6.9		0.2		24.3
Total Customer Revenues	$	1,426.0	$	408.3	$	0.2	$	1,834.5
Other Revenues	12.8		22.5		—		35.3
Total Operating Revenues	$	1,438.8	$	430.8	$	0.2	$	1,869.8
(1) Customer revenue amounts exclude intersegment revenues. See Note 21, "Business Segment Information," for discussion of intersegment revenues.

Customer Accounts Receivable

The opening and closing balances of customer receivables for the three months ended March 31, 2020 are presented in the table below. We had no significant contract assets or liabilities during the period. Additionally, we have not incurred any significant costs to obtain or fulfill contracts.

(in millions)	Customer Accounts Receivable, Billed (less reserve)			Customer Accounts Receivable, Unbilled (less reserve)
Balance as of December 31, 2019	$	466.6		$	346.6
Balance as of March 31, 2020	449.9			233.5
Decrease	$	(16.7	)	$	(113.1	)

Financing Receivable, Allowance for Credit Loss

A rollforward of our allowance for credit losses for the three months ended March 31, 2020 are presented in the table below:

Three Months Ended March 31, 2020 (in millions)	Gas Distribution Operations			Electric Operations			Corporate and Other		Total
Beginning balance(1)	$	9.1		$	3.1		$	0.8	$	13.0
Current period provisions	9.1			1.5			—		10.6
Write-offs charged against allowance	(6.9		)	(1.0		)	—		(7.9		)
Recoveries of amounts previously written off	4.6			—			—		4.6
Ending balance of the allowance for credit losses	$	15.9		$	3.6		$	0.8	$	20.3
(1)Total beginning balance differs from that presented in the Condensed Statements of Consolidated Balance Sheet (unaudited) as it excludes Columbia of Massachusetts. Columbia of Massachusetts' customer receivables and related allowance for credit losses are classified as held for sale at March 31, 2020.