Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Accounts receivable, net (Note 3)	$ 233.0	$ 219.1
Inventories (Note 3)	96.3	125.8
Regulatory assets, current (Note 4)	21.8	20.8
Other noncurrent assets:
Regulatory assets, non-current (Note 4)	181.3	193.2
Goodwill	2,576.3
Current liabilities:
Regulatory liabilities, current (Note 4)		0.5
Noncurrent liabilities:
Regulatory liabilities, non-current (Note 4)	117.5	118.6
Common shareholders' equity:
Accumulated other comprehensive loss	(6.3)	(0.4)
THE DAYTON POWER AND LIGHT COMPANY [Member]
Current assets:
Cash and cash equivalents	19.4	32.2
Restricted Cash	19.5	14.3
Accounts receivable, net (Note 3)	171.8	178.5
Inventories (Note 3)	95.1	123.1
Taxes applicable to subsequent years	15.7	71.9
Regulatory assets, current (Note 4)	18.9	17.7
Other prepayments and current assets	17.3	23.2
Total current assets	357.7	460.9
Property, plant and equipment:
Property, plant and equipment	5,216.4	5,277.9
Less: Accumulated depreciation and amortization	(2,500.0)	(2,568.9)
Property, plant and equipment, net of depreciation	2,716.4	2,709.0
Construction work in process	99.0	150.7
Total net property, plant and equipment	2,815.4	2,859.7
Other noncurrent assets:
Regulatory assets, non-current (Note 4)	181.3	177.8
Intangible asset, net of amortization	11.4	6.5
Other deferred assets	20.8	33.4
Total other noncurrent assets	213.5	217.7
Total Assets	3,386.6	3,538.3
Current liabilities:
Current portion - long-term debt (Note 6)	0.4	0.4
Accounts payable	74.1	106.0
Accrued taxes	108.7	72.8
Accrued interest	15.6	7.9
Customer security deposits	15.9	15.8
Other current liabilities	60.5	46.1
Total current liabilities	275.2	249.0
Noncurrent liabilities:
Long-term debt (Note 6)	902.8	903.0
Deferred taxes (Note 7)	644.0	637.7
Taxes Payable	25.5	93.9
Regulatory liabilities, non-current (Note 4)	117.5	118.6
Pension, retiree and other benefits	55.7	47.5
Derivative liability	5.2	11.8
Unamortized investment tax credit	28.0	29.9
Other deferred credits	43.5	66.1
Total noncurrent liabilities	1,822.2	1,908.5
Redeemable preferred stock	22.9	22.9
Common shareholders' equity:
Common stock, at par value of $0.01 per share:	0.4	0.4
Other paid-in capital	802.5	803.1
Accumulated other comprehensive loss	(38.3)	(34.7)
Retained earnings	501.7	589.1
Total common shareholders' equity	1,266.3	1,357.9
Total Liabilities and Shareholders' Equity	3,386.6	3,538.3
Successor [Member]
Current assets:
Cash and cash equivalents	205.6	173.5
Restricted Cash	22.6
Accounts receivable, net (Note 3)	233.0
Inventories (Note 3)	96.3
Taxes applicable to subsequent years	16.6
Regulatory assets, current (Note 4)	21.8
Other prepayments and current assets	26.4
Total current assets	622.3
Property, plant and equipment:
Property, plant and equipment	2,629.1
Less: Accumulated depreciation and amortization	(173.8)
Property, plant and equipment, net of depreciation	2,455.3
Construction work in process	100.1
Total net property, plant and equipment	2,555.4
Other noncurrent assets:
Regulatory assets, non-current (Note 4)	181.3
Goodwill	726.3
Intangible asset, net of amortization	75.0
Other deferred assets	33.9
Total other noncurrent assets	1,016.5
Total Assets	4,194.2
Current liabilities:
Current portion - long-term debt (Note 6)	0.4	0.4
Accounts payable	78.6	111.1
Accrued taxes	88.9	63.2
Accrued interest	55.7	30.2
Customer security deposits	15.9	15.9
Regulatory liabilities, current (Note 4)		0.5
Dividends payable	25.0
Insurance and claims costs	12.9	14.2
Other current liabilities	68.9	68.4
Total current liabilities	346.3	303.9
Noncurrent liabilities:
Long-term debt (Note 6)	2,614.5	2,628.9
Deferred taxes (Note 7)	523.3	542.4
Taxes Payable	24.5	96.9
Regulatory liabilities, non-current (Note 4)	117.5	118.6
Pension, retiree and other benefits	55.7	47.5
Derivative liability	41.1	46.1
Unamortized investment tax credit	3.4	3.6
Other deferred credits	73.3	100.2
Total noncurrent liabilities	3,453.3	3,584.2
Redeemable preferred stock	18.4	18.4
Common shareholders' equity:
Other paid-in capital	2,235.9	2,237.3
Accumulated other comprehensive loss	(6.3)	(0.4)
Retained earnings	(1,853.4)	(6.2)
Total common shareholders' equity	376.2	2,230.7
Total Liabilities and Shareholders' Equity	4,194.2	6,137.2
Predecessor [Member]
Current assets:
Cash and cash equivalents		173.5
Restricted Cash		22.2
Accounts receivable, net (Note 3)		219.1
Inventories (Note 3)		125.8
Taxes applicable to subsequent years		76.5
Regulatory assets, current (Note 4)		20.8
Other prepayments and current assets		30.4
Total current assets		668.3
Property, plant and equipment:
Property, plant and equipment		2,360.3
Less: Accumulated depreciation and amortization		(7.5)
Property, plant and equipment, net of depreciation		2,352.8
Construction work in process		152.3
Total net property, plant and equipment		2,505.1
Other noncurrent assets:
Regulatory assets, non-current (Note 4)		193.2
Goodwill		2,576.3
Intangible asset, net of amortization		142.4
Other deferred assets		51.9
Total other noncurrent assets		2,963.8
Total Assets		$ 6,137.2