Financial and Other Derivative Instruments (Details 1)	Jun. 30, 2012 deted.volumes
Derivative [Line Items]
Investment Contract Volume	108,832

The volume of a commodity or material specified in an investment contract.

No definition available.

Name:	invest_InvestmentContractVolume
Namespace Prefix:	invest_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	instant