Investments (Repurchase Agreements - Narrative) (Details)	Jun. 30, 2017
Repurchase Agreements [Member]
Securities Financing Transaction [Line Items]
Percentage of Reinvestment Portfolio in Fixed Maturity Securities	65.00%

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.

Name:	us-gaap_SecuritiesFinancingTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration