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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
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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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
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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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Goodwill and Other Intangibles - Changes in the carrying value of goodwill (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Changes in the carrying value of goodwill by reporting segment
Goodwill, Beginning balance	$ 207	$ 207	$ 199	$ 199	$ 199
Goodwill, acquisition of subsidiary	8	8
Goodwill, Ending balance	207	207
Property and Casualty
Changes in the carrying value of goodwill by reporting segment
Goodwill, Beginning balance	176	176	168	168	168
Goodwill, acquisition of subsidiary		8
Goodwill, Ending balance	176	176
Annuity
Changes in the carrying value of goodwill by reporting segment
Goodwill, Beginning balance	31	31	$ 31	$ 31	$ 31
Goodwill, acquisition of subsidiary		0
Goodwill, Ending balance	$ 31	$ 31