Supplemental Financial Information (Tables)

12 Months Ended

Dec. 31, 2020

Supplemental Financial Information [Line Items]

Accounts Receivable, Allowance for Credit Loss

The following table is a rollforward of our allowance for credit losses related to the accounts receivable balances for the year ended December 31, 2020:

$ in millions	Beginning Allowance Balance at January 1, 2020		Current Period Provision		Write-offs Charged Against Allowances		Recoveries Collected		Ending Allowance Balance at December 31, 2020
Allowance for credit losses	$	0.4	$	3.0	$	(2.3)	$	1.7	$	2.8

Supplemental Financial Information

	December 31,
$ in millions	2020		2019
Accounts receivable, net
Customer receivables	$	48.5	$	45.7
Unbilled revenue	21.6		19.4
Amounts due from affiliates	0.2		0.3
Due from PJM transmission enhancement settlement (a)	1.7		1.8
Other	0.5		1.1
Allowance for credit losses	(2.8)		(0.4)
Total accounts receivable, net	$	69.7	$	67.9

Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]

The amounts reclassified out of Accumulated Other Comprehensive Income / (Loss) by component during the years ended December 31, 2020, 2019 and 2018 are as follows:

Details about Accumulated Other Comprehensive Income / (Loss) Components	Affected line item in the Consolidated Statements of Operations	Years ended December 31,
$ in millions		2020		2019		2018
Gains and losses on cash flow hedges (Note 6):
	Interest expense	(1.1)		(1.2)		(1.2)
	Income tax expense	0.2		0.1		0.4
	Net of income taxes	(0.9)		(1.1)		(0.8)
	Loss from discontinued operations	—		—		4.4
	Tax benefit from discontinued operations	—		(0.4)		(1.2)
	Net of income taxes	—		(0.4)		3.2
Amortization of defined benefit pension items (Note 9):
	Other expense	1.3		0.2		0.8
	Income tax benefit	(0.3)		—		(0.2)
	Net of income taxes	1.0		0.2		0.6
Total reclassifications for the period, net of income taxes		$	0.1	$	(1.3)	$	3.0

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The changes in the components of Accumulated Other Comprehensive Income / (Loss) during the years ended December 31, 2020 and 2019 are as follows:

$ in millions	Gains / (losses) on cash flow hedges		Change in unfunded pension obligation		Total
Balance at January 1, 2019	$	17.0	$	(14.8)	$	2.2
Other comprehensive loss before reclassifications	(1.0)		(3.5)		(4.5)
Amounts reclassified from accumulated other comprehensive income / (loss) to earnings	(1.5)		0.2		(1.3)
Net current period other comprehensive loss	(2.5)		(3.3)		(5.8)
Balance at December 31, 2019	14.5		(18.1)		(3.6)
Other comprehensive loss before reclassifications	—		(8.8)		(8.8)
Amounts reclassified from accumulated other comprehensive loss to earnings	(0.9)		1.0		0.1
Net current period other comprehensive loss	(0.9)		(7.8)		(8.7)
Balance at December 31, 2020	$	13.6	$	(25.9)	$	(12.3)

THE DAYTON POWER AND LIGHT COMPANY [Member]

Supplemental Financial Information [Line Items]

Accounts Receivable, Allowance for Credit Loss

The following table is a rollforward of our allowance for credit losses related to the accounts receivable balances for the year ended December 31, 2020:

$ in millions	Beginning Allowance Balance at January 1, 2020		Current Period Provision		Write-offs Charged Against Allowances		Recoveries Collected		Ending Allowance Balance at December 31, 2020
Allowance for credit losses	$	0.4	$	3.0	$	(2.3)	$	1.7	$	2.8

Supplemental Financial Information

Accounts receivable are as follows at December 31, 2020 and 2019:

	December 31,
$ in millions	2020		2019
Accounts receivable, net
Customer receivables	$	47.6	$	45.0
Unbilled revenue	21.6		19.4
Amounts due from affiliates	1.9		3.9
Due from PJM transmission enhancement settlement (a)	1.7		1.8
Other	0.2		1.2
Allowance for credit losses	(2.8)		(0.4)
Total accounts receivable, net	$	70.2	$	70.9

(a)    See Note 3 – Regulatory Matters for more information.

Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]

The amounts reclassified out of Accumulated Other Comprehensive Loss by component during the years ended December 31, 2020, 2019 and 2018 are as follows:

Details about Accumulated Other Comprehensive Income / (Loss) Components	Affected line item in the Statements of Operations	Years ended December 31,
$ in millions		2020		2019		2018
Gains and losses on cash flow hedges (Note 6):
	Interest expense	(0.2)		(0.2)		(1.1)
	Income tax expense	0.8		—		0.4
	Net of income taxes	0.6		(0.2)		(0.7)
Amortization of defined benefit pension items (Note 9):
	Other expense	4.0		3.5		4.3
	Income tax benefit	(0.9)		(0.5)		(1.0)
	Net of income taxes	3.1		3.0		3.3
Total reclassifications for the period, net of income taxes		$	3.7	$	2.8	$	2.6

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The changes in the components of Accumulated Other Comprehensive Income Loss during the years ended December 31, 2020 and 2019 are as follows:

$ in millions	Gains / (losses) on cash flow hedges		Change in unfunded pension obligation		Total
Balance at January 1, 2019	$	0.6	$	(35.9)	$	(35.3)
Other comprehensive loss before reclassifications	(0.8)		(3.6)		(4.4)
Amounts reclassified from accumulated other comprehensive loss to earnings	(0.2)		3.0		2.8
Net current period other comprehensive loss	(1.0)		(0.6)		(1.6)
Balance at December 31, 2019	(0.4)		(36.5)		(36.9)
Other comprehensive loss before reclassifications	(0.2)		(8.7)		(8.9)
Amounts reclassified from accumulated other comprehensive loss to earnings	0.6		3.1		3.7
Net current period other comprehensive income / (loss)	0.4		(5.6)		(5.2)
Balance at December 31, 2020	$	—	$	(42.1)	$	(42.1)