Condensed Consolidated Balance Sheets (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 72.8	$ 124.0
Short-term investments		69.3
Accounts receivable, net (Note 2)	201.8	215.5
Inventories (Note 2)	115.6	115.3
Taxes applicable to subsequent years	31.8	63.7
Other prepayments and current assets	69.4	40.6
Total current assets	491.4	628.4
Property, plant and equipment:
Property, plant and equipment	5,482.6	5,353.6
Less: Accumulated depreciation and amortization	(2,629.3)	(2,555.2)
Property, plant and equipment, net of depreciation	2,853.3	2,798.4
Construction work in process	112.3	119.7
Total net property, plant and equipment	2,965.6	2,918.1
Other noncurrent assets:
Regulatory assets (Note 3)	178.8	189.0
Other deferred assets	75.8	77.8
Total other noncurrent assets	254.6	266.8
Total Assets	3,711.6	3,813.3
Current liabilities:
Current portion - long-term debt (Note 5)	297.8	297.5
Accounts payable	94.6	98.7
Accrued taxes	70.9	68.1
Accrued interest	20.6	18.4
Customer security deposits	17.9	18.7
Other current liabilities	55.6	40.9
Total current liabilities	557.4	542.3
Noncurrent liabilities:
Long-term debt (Note 5)	923.6	1,026.6
Deferred taxes (Note 6)	660.6	625.4
Regulatory liabilities (Note 3)	129.4	124.0
Pension, retiree and other benefits	27.6	64.9
Unamortized investment tax credit	31.0	32.4
Insurance and claims costs	13.7	10.1
Other deferred credits	110.9	146.2
Total noncurrent liabilities	1,896.8	2,029.6
Redeemable preferred stock	22.9	22.9
Commitments and contingencies (Note 14)
Common shareholders' equity:
Common stock, at par value of $0.01 per share:	1.2	1.2
Warrants	1.6	2.7
Common stock held by employee plans	(8.1)	(12.5)
Accumulated other comprehensive loss	(26.1)	(18.9)
Retained earnings	1,265.9	1,246.0
Total common shareholders' equity	1,234.5	1,218.5
Total Liabilities and Shareholders' Equity	3,711.6	3,813.3
THE DAYTON POWER AND LIGHT COMPANY [Member]
Current assets:
Cash and cash equivalents	12.7	54.0
Accounts receivable, net (Note 2)	150.4	178.0
Inventories (Note 2)	114.1	114.2
Taxes applicable to subsequent years	31.4	62.8
Other prepayments and current assets	60.6	42.7
Total current assets	369.2	451.7
Property, plant and equipment:
Property, plant and equipment	5,218.0	5,093.7
Less: Accumulated depreciation and amortization	(2,523.7)	(2,453.1)
Property, plant and equipment, net of depreciation	2,694.3	2,640.6
Construction work in process	112.7	119.6
Total net property, plant and equipment	2,807.0	2,760.2
Other noncurrent assets:
Regulatory assets (Note 3)	178.8	189.0
Other deferred assets	80.0	74.5
Total other noncurrent assets	258.8	263.5
Total Assets	3,435.0	3,475.4
Current liabilities:
Current portion - long-term debt (Note 5)	0.4	0.1
Accounts payable	87.0	95.7
Accrued taxes	70.3	66.6
Accrued interest	13.3	7.7
Customer security deposits	17.8	18.7
Other current liabilities	33.8	33.6
Total current liabilities	222.6	222.4
Noncurrent liabilities:
Long-term debt (Note 5)	903.0	884.0
Deferred taxes (Note 6)	636.5	598.0
Regulatory liabilities (Note 3)	129.4	124.0
Pension, retiree and other benefits	27.6	64.9
Unamortized investment tax credit	31.0	32.4
Other deferred credits	111.0	147.3
Total noncurrent liabilities	1,838.5	1,850.6
Redeemable preferred stock	22.9	22.9
Commitments and contingencies (Note 14)
Common shareholders' equity:
Common stock, at par value of $0.01 per share:	0.4	0.4
Other paid-in capital	782.6	782.4
Accumulated other comprehensive loss	(17.0)	(20.2)
Retained earnings	585.0	616.9
Total common shareholders' equity	1,351.0	1,379.5
Total Liabilities and Shareholders' Equity	$ 3,435.0	$ 3,475.4