Earnings Per Unit (Details Textual)	6 Months Ended
Jun. 30, 2012
Earnings Per Unit (Textual) [Abstract]
OCGH Issued	120,250,753
OCGH units represented	120,250,753
Additional class A units	115,000,000

Potential additional Class A units issuable through March two thousand twenty two through conversion of units held by noncontrolling interest.

No definition available.

Name:	oak_PotentialAdditionalClassUnitsIssuableThroughMarchTwoThousandTwentyTwoThroughConversionOfUnitsHeldByNoncontrollingInterest
Namespace Prefix:	oak_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant