Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=64834752&loc=SL49117168-202975

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- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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Goodwill and Other Intangibles - Changes in the carrying value of goodwill (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Jun. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2013
Changes in the carrying value of goodwill by reporting segment
Goodwill, Beginning balance	$ 199		$ 199	$ 201	$ 199	$ 185
Goodwill, Acquired during period		$ 16		16
Goodwill, Sale of subsidiary	(2)		(2)
Goodwill, Ending balance	199		199	201
Property and Casualty
Changes in the carrying value of goodwill by reporting segment
Goodwill, Beginning balance	168		168	168	168	152
Goodwill, Acquired during period				16
Goodwill, Sale of subsidiary			0
Goodwill, Ending balance	168		168	168
Annuity
Changes in the carrying value of goodwill by reporting segment
Goodwill, Beginning balance	31		31	33	$ 31	$ 33
Goodwill, Acquired during period				0
Goodwill, Sale of subsidiary			(2)
Goodwill, Ending balance	$ 31		$ 31	$ 33