Counterparty Risk (% Of Due from Brokers) (Details)	Jun. 30, 2015
Wells Fargo Bank N.A. [Member]
Concentration Risk [Line Items]
% of Total Due from Brokers	26.00%
Morgan Stanley [Member]
Concentration Risk [Line Items]
% of Total Due from Brokers	24.00%
JP Morgan Securities Inc [Member]
Concentration Risk [Line Items]
% of Total Due from Brokers	18.00%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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