Condensed Consolidated Balance Sheets (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 67.6	$ 124.0
Short-term investments	0	69.3
Accounts receivable, net (Note 2)	203.2	215.5
Inventories (Note 2)	126.8	115.3
Taxes applicable to subsequent years	15.9	63.7
Other prepayments and current assets	68.6	40.6
Total current assets	482.1	628.4
Property, plant and equipment:
Property, plant and equipment	5,508.3	5,353.6
Less: Accumulated depreciation and amortization	(2,652.7)	(2,555.2)
Property, plant and equipment, net of depreciation	2,855.6	2,798.4
Construction work in process	118.6	119.7
Total net property, plant and equipment	2,974.2	2,918.1
Other noncurrent assets:
Regulatory assets (Note 3)	178.2	189.0
Other deferred assets	42.0	77.8
Total other noncurrent assets	220.2	266.8
Total Assets	3,676.5	3,813.3
Current liabilities:
Current portion - long-term debt (Note 5)	0.4	297.5
Accounts payable	82.2	98.7
Accrued taxes	72.4	68.1
Accrued interest	15.6	18.4
Customer security deposits	16.9	18.7
Other current liabilities	37.0	40.9
Total current liabilities	224.5	542.3
Noncurrent liabilities:
Long-term debt (Note 5)	1,223.6	1,026.6
Deferred taxes (Note 6)	670.0	625.4
Regulatory liabilities (Note 3)	133.1	124.0
Pension, retiree and other benefits	25.9	64.9
Unamortized investment tax credit	30.3	32.4
Insurance and claims costs	14.1	10.1
Other deferred credits	112.6	146.2
Total noncurrent liabilities	2,209.6	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	(7.1)	(12.5)
Accumulated other comprehensive loss	(72.1)	(18.9)
Retained earnings	1,295.9	1,246.0
Total common shareholders' equity	1,219.5	1,218.5
Total Liabilities and Shareholders' Equity	3,676.5	3,813.3
THE DAYTON POWER AND LIGHT COMPANY [Member]
Current assets:
Cash and cash equivalents	21.7	54.0
Accounts receivable, net (Note 2)	152.5	178.0
Inventories (Note 2)	125.6	114.2
Taxes applicable to subsequent years	15.7	62.8
Other prepayments and current assets	45.2	42.7
Total current assets	360.7	451.7
Property, plant and equipment:
Property, plant and equipment	5,243.8	5,093.7
Less: Accumulated depreciation and amortization	(2,545.2)	(2,453.1)
Property, plant and equipment, net of depreciation	2,698.6	2,640.6
Construction work in process	118.0	119.6
Total net property, plant and equipment	2,816.6	2,760.2
Other noncurrent assets:
Regulatory assets (Note 3)	178.2	189.0
Other deferred assets	64.2	74.5
Total other noncurrent assets	242.4	263.5
Total Assets	3,419.7	3,475.4
Current liabilities:
Current portion - long-term debt (Note 5)	0.4	0.1
Accounts payable	75.1	95.7
Accrued taxes	70.3	66.6
Accrued interest	15.5	7.7
Customer security deposits	16.9	18.7
Other current liabilities	33.8	33.6
Total current liabilities	212.0	222.4
Noncurrent liabilities:
Long-term debt (Note 5)	903.0	884.0
Deferred taxes (Note 6)	656.4	598.0
Regulatory liabilities (Note 3)	133.1	124.0
Pension, retiree and other benefits	25.9	64.9
Unamortized investment tax credit	30.3	32.4
Other deferred credits	84.4	147.3
Total noncurrent liabilities	1,833.1	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	782.8	782.4
Accumulated other comprehensive loss	(15.1)	(20.2)
Retained earnings	583.6	616.9
Total common shareholders' equity	1,351.7	1,379.5
Total Liabilities and Shareholders' Equity	$ 3,419.7	$ 3,475.4