Power Purchase Agreements (Schedule Of Energy And Capacity Purchase Obligations) (Details) $ in Millions	12 Months Ended
Dec. 31, 2016 USD ($)
Regulated Operations [Abstract]
2017	$ 180.0
2018	170.1
2019	182.0
Energy and Capacity Obligations	$ 532.1

Energy and capacity purchase commitments in the next twelve months.

No definition available.

Name:	cik0000885568_EnergyAndCapacityPurchaseCommitmentsInNextTwelveMonths
Namespace Prefix:	cik0000885568_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration