Business Combinations - Pro Forma (Details) - Delta Lloyd Deutschland - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Pro Forma Information
Revenue	$ 3,002	$ 4,622
Net income	$ 579	$ 473

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration