Investments in Unconsolidated Affiliates (Details) - USD ($)	12 Months Ended
Dec. 31, 2014	Nov. 05, 2015
Safeco Corporation [Member]
Investments in and Advances to Affiliates [Line Items]
Payments to Acquire Interest in Subsidiaries and Affiliates	$ 1,350,000,000
Symetra
Investments in and Advances to Affiliates [Line Items]
Payments to Acquire Interest in Subsidiaries and Affiliates	195,000,000
Symetra \| Common Stock
Investments in and Advances to Affiliates [Line Items]
Investments in unconsolidated affiliates	$ 411,400,000	$ 392,800,000

The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

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