Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Future Policy Benefits) (Narrative) (Details)	Dec. 31, 2016
Maximum [Member]
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items]
Long-Duration Contracts, Assumptions by Product and Guarantee, Discount Rate	6.00%
Minimum [Member]
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items]
Long-Duration Contracts, Assumptions by Product and Guarantee, Discount Rate	3.00%

Percentage discount rate used to calculate present value of an expected stream of future payments, which is included in the calculation of the amount of the specified guaranteed benefit obligation as of the balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 80
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6484115&loc=d3e19393-158473

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6482852&loc=d3e14931-158439

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 55
-Paragraph 15
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=6588021&loc=d3e7104-158389

Name:	us-gaap_LongDurationContractsAssumptionsByProductAndGuaranteeDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant