Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 251.3	$ 192.1
Restricted Cash	23.4	10.7
Accounts receivable, net (Note 2)	190.1	208.2
Inventories (Note 2)	114.5	110.1
Taxes applicable to subsequent years	52.1	69.3
Regulatory assets, current (Note 3)	18.0	21.1
Other prepayments and current assets	43.0	43.1
Total current assets	692.4	654.6
Property, plant and equipment:
Property, plant and equipment	2,625.7	2,590.4
Less: Accumulated depreciation and amortization	(134.6)	(115.9)
Property, plant and equipment, net of depreciation	2,491.1	2,474.5
Construction work in process	70.9	89.3
Total net property, plant and equipment	2,562.0	2,563.8
Other noncurrent assets:
Regulatory assets, non-current (Note 3)	180.9	185.5
Goodwill	759.1	759.1
Intangible assets, Net of amortization	50.0	50.1
Other deferred assets	29.9	34.2
Total other noncurrent assets	1,019.9	1,028.9
Total Assets	4,274.3	4,247.3
Current liabilities:
Current portion - long-term debt (Note 5)	580.1	584.9
Accounts payable	80.8	83.2
Accrued taxes	63.5	97.1
Accrued interest	55.5	31.8
Customer security deposits	14.7	15.0
Regulatory liabilities, current (Note 3)		0.1
Insurance and claims costs	12.5	11.5
Other current liabilities	86.3	96.9
Total current liabilities	893.4	920.5
Noncurrent liabilities:
Long-term debt (Note 5)	2,025.0	2,025.0
Deferred taxes (Note 6)	558.2	534.9
Taxes Payable	68.1	68.1
Regulatory liabilities, non-current (Note 3)	118.8	117.3
Pension, retiree and other benefits	63.2	61.6
Unamortized investment tax credit	3.1	3.3
Other deferred credits	71.5	71.4
Total noncurrent liabilities	2,907.9	2,881.6
Redeemable preferred stock	18.4	18.4
Common shareholders' equity:
Other paid-in capital	2,236.7	2,236.7
Accumulated other comprehensive loss	(1.9)	(3.9)
Retained deficit	(1,780.2)	(1,806.0)
Total common shareholders' equity	454.6	426.8
Total Liabilities and Shareholders' Equity	4,274.3	4,247.3
THE DAYTON POWER AND LIGHT COMPANY [Member]
Current assets:
Cash and cash equivalents	28.3	28.5
Restricted Cash	23.4	10.7
Accounts receivable, net (Note 2)	148.2	160.0
Inventories (Note 2)	113.2	108.9
Taxes applicable to subsequent years	50.0	66.7
Regulatory assets, current (Note 3)	16.6	18.3
Other prepayments and current assets	34.9	33.0
Total current assets	414.6	426.1
Property, plant and equipment:
Property, plant and equipment	5,270.6	5,249.0
Less: Accumulated depreciation and amortization	(2,525.2)	(2,516.3)
Property, plant and equipment, net of depreciation	2,745.4	2,732.7
Construction work in process	70.4	87.8
Total net property, plant and equipment	2,815.8	2,820.5
Other noncurrent assets:
Regulatory assets, non-current (Note 3)	180.9	185.5
Intangible assets, Net of amortization	9.4	9.0
Other deferred assets	18.9	23.1
Total other noncurrent assets	209.2	217.6
Total Assets	3,439.6	3,464.2
Current liabilities:
Current portion - long-term debt (Note 5)	570.4	570.4
Accounts payable	76.7	79.1
Accrued taxes	66.9	92.2
Accrued interest	15.4	13.1
Customer security deposits	33.9	35.2
Regulatory liabilities, current (Note 3)		0.1
Other current liabilities	56.0	52.1
Total current liabilities	819.3	842.2
Noncurrent liabilities:
Long-term debt (Note 5)	332.7	332.7
Deferred taxes (Note 6)	673.3	652.0
Taxes Payable	66.0	66.0
Regulatory liabilities, non-current (Note 3)	118.8	117.3
Pension, retiree and other benefits	63.2	61.6
Unamortized investment tax credit	26.8	27.4
Other deferred credits	44.0	43.0
Total noncurrent liabilities	1,324.8	1,300.0
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	803.3	803.2
Accumulated other comprehensive loss	(40.3)	(38.7)
Retained deficit	509.2	534.2
Total common shareholders' equity	1,272.6	1,299.1
Total Liabilities and Shareholders' Equity	$ 3,439.6	$ 3,464.2