Counterparty Risk (% Of Total Collateral On Reverse Repurchase Agreements) (Details)	Dec. 31, 2017
Royal Bank of Canada [Member]
Concentration Risk [Line Items]
Percentage of Total Collateral On Reverse Repurchase Agreements	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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