Inventories (Details Textual) (USD $) In Millions, unless otherwise specified	9 Months Ended
Jun. 30, 2012	Jun. 30, 2011
Inventories (Textual) [Abstract]
Non-cash transfers of inventories to rental equipment fleet	$ 0.9	$ 0.2

Non-cash transfers of inventories to rental equipment fleet.

No definition available.

Name:	oyog_NonCashTransfersOfInventoriesToRentalEquipmentFleet
Namespace Prefix:	oyog_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration