Benefit Plans (Estimated Future Benefit Payments and Medicare Part D Reimbursements) (Details) $ in Millions	Sep. 30, 2016 USD ($)
Pension [Member]
2016	$ 6.2
2017	25.2
2018	25.8
2019	26.3
2020	26.7
2021 - 2025	134.8
Postretirement [Member]
2016	0.4
2017	1.6
2018	1.5
2019	1.4
2020	1.4
2021 - 2025	5.7
THE DAYTON POWER AND LIGHT COMPANY [Member] \| Pension [Member]
2016	6.2
2017	25.2
2018	25.8
2019	26.3
2020	26.7
2021 - 2025	134.8
THE DAYTON POWER AND LIGHT COMPANY [Member] \| Postretirement [Member]
2016	0.4
2017	1.6
2018	1.5
2019	1.4
2020	1.4
2021 - 2025	$ 5.7

Amount of benefits from a defined benefit plan expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

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Amount of benefits from a defined benefit plan expected to be paid in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of benefits from a defined benefit plan expected to be paid in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of benefits from a defined benefit plan expected to be paid in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of benefits from a defined benefit plan expected to be paid in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of benefits from a defined benefit plan expected to be paid in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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