Investments (Repurchase Agreements - Narrative) (Details)	Sep. 30, 2017
Repurchase Agreements [Member]
Securities Financing Transaction [Line Items]
Percentage of Reinvestment Portfolio in Fixed Maturity Securities	67.00%

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.

No definition available.

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