Supplemental Financial Information (Tables)

6 Months Ended

Jun. 30, 2015

Supplemental Financial Information [Line Items]

Schedule of Supplemental Financial Information

Accounts receivable and Inventories are as follows at June 30, 2015 and December 31, 2014:

	June 30,			December 31,
$ in millions	2015			2014
Accounts receivable, net:
Unbilled revenue	$	61.9		$	79.2
Customer receivables	92.0			104.8
Amounts due from partners in jointly owned plants	20.0			14.2
Other	3.2			4.0
Provision for uncollectible accounts	(1.4		)	(1.3		)
Total accounts receivable, net	$	175.7		$	200.9
Inventories, at average cost:
Fuel and limestone	$	67.8		$	65.3
Plant materials and supplies	34.8			33.5
Other	2.1			1.4
Total inventories, at average cost	$	104.7		$	100.2

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

The amounts reclassified out of Accumulated Other Comprehensive Income / (Loss) by component during the six months endedJune 30, 2015 and 2014 are as follows:

Details about Accumulated Other Comprehensive Income / (Loss) components	Affected line item in the Condensed Consolidated Statements of Operations	Three months ended						Six months ended
		June 30,						June 30,
$ in millions		2015			2014			2015			2014
Gains and losses on Available-for-sale securities activity (Note 8):
	Other income	$	0.6		$	—		$	—		$	0.3
	Tax expense	(0.2		)	—			—			(0.1		)
	Net of income taxes	0.4			—			—			0.2
Gains and losses on cash flow hedges (Note 9):
	Interest expense	(0.3		)	(0.2		)	(0.5		)	(0.7		)
	Revenue	(2.9		)	8.3			(3.2		)	18.5
	Purchased power	0.4			(0.1		)	1.8			(1.2		)
	Total before income taxes	(2.8		)	8.0			(1.9		)	16.6
	Tax expense	0.9			(2.7		)	0.5			(5.8		)
	Net of income taxes	(1.9		)	5.3			(1.4		)	10.8
Amortization of defined benefit pension items (Note 7):
	Other income	0.1			—			0.2			—
	Tax expense	(0.5		)	—			(0.4		)	—
	Net of income taxes	(0.4		)	—			(0.2		)	—
Total reclassifications for the period, net of income taxes		$	(1.9	)	$	5.3		$	(1.6	)	$	11.0

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

The changes in the components of Accumulated Other Comprehensive Income / (Loss) during the six months endedJune 30, 2015 are as follows:

$ in millions	Gains / (losses) on available-for-sale securities		Gains / (losses) on cash flow hedges			Change in unfunded pension obligation			Total
Balance January 1, 2015	$	0.5	$	18.5		$	(11.5	)	$	7.5
Other comprehensive income before reclassifications	0.1		1.8			—			1.9
Amounts reclassified from accumulated other comprehensive income / (loss)	—		(1.4		)	(0.2		)	(1.6		)
Net current period other comprehensive income / (loss)	0.1		0.4			(0.2		)	0.3
Balance June 30, 2015	$	0.6	$	18.9		$	(11.7	)	$	7.8

THE DAYTON POWER AND LIGHT COMPANY [Member]

Supplemental Financial Information [Line Items]

Schedule of Supplemental Financial Information

Accounts receivable and Inventories are as follows at June 30, 2015 and December 31, 2014:

	June 30,			December 31,
$ in millions	2015			2014
Accounts receivable, net:
Unbilled revenue	$	43.5		$	49.0
Customer receivables	69.5			68.7
Amounts due from partners in jointly owned plants	20.0			14.2
Other	5.6			21.7
Provision for uncollectible accounts	(1.0		)	(0.9		)
Total accounts receivable, net	$	137.6		$	152.7
Inventories, at average cost:
Fuel and limestone	$	67.8		$	65.3
Plant materials and supplies	33.7			32.3
Other	2.0			1.4
Total inventories, at average cost	$	103.5		$	99.0

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

The amounts reclassified out of Accumulated Other Comprehensive Income / (Loss) by component during the three and six months ended June 30, 2015 and 2014 are as follows:

Details about Accumulated Other Comprehensive Income / (Loss) components	Affected line item in the Condensed Statements of Operations	Three months ended						Six months ended
		June 30,						June 30,
$ in millions		2015			2014			2015			2014
Gains and losses on Available-for-sale securities activity (Note 8):
	Other income	$	0.6		$	—		$	—		$	0.3
	Tax expense	(0.2		)	—			—			(0.1		)
	Net of income taxes	0.4			—			—			0.2
Gains and losses on cash flow hedges (Note 9):
	Interest expense	(0.3		)	(0.3		)	(0.6		)	(0.6		)
	Revenue	(2.9		)	8.3			(3.2		)	18.5
	Purchased power	0.4			—			1.8			(1.0		)
	Total before income taxes	(2.8		)	8.0			(2.0		)	16.9
	Tax expense	1.0			(1.6		)	0.7			(4.8		)
	Net of income taxes	(1.8		)	6.4			(1.3		)	12.1
Amortization of defined benefit pension items (Note 7):
	Reclassification to Other income / (deductions)	1.4			1.1			2.8			2.1
	Tax benefit	(0.5		)	(0.3		)	(1.0		)	(0.7		)
	Net of income taxes	0.9			0.8			1.8			1.4
Total reclassifications for the period, net of income taxes		$	(0.5	)	$	7.2		$	0.5		$	13.7

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

The changes in the components of Accumulated Other Comprehensive Income / (Loss) during the six months ended June 30, 2015 are as follows:

$ in millions	Gains / (losses) on available-for-sale securities		Gains / (losses) on cash flow hedges			Change in unfunded pension obligation			Total
Balance January 1, 2015	$	0.7	$	2.8		$	(45.8	)	$	(42.3	)
Other comprehensive income before reclassifications	—		1.8			—			1.8
Amounts reclassified from accumulated other comprehensive income / (loss)	—		(1.3		)	1.8			0.5
Net current period other comprehensive income	—		0.5			1.8			2.3
Balance June 30, 2015	$	0.7	$	3.3		$	(44.0	)	$	(40.0	)