Amount, after accumulated amortization, of deferred policy acquisition costs and present value of future profits from insurance contract acquired in business combination.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35755530&loc=d3e11264-158415

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.7)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section S99
-Paragraph 2
-Subparagraph (2)
-URI http://asc.fasb.org/extlink&oid=27015749&loc=d3e569990-122904

Name:	us-gaap_DeferredPolicyAcquisitionCostsAndValueOfBusinessAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Deferred Policy Acquisition Costs, Value of Business Acquired and Other Policy-Related Intangibles (DAC and VOBA by Segment) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
DAC and VOBA	$ 5,623	$ 6,339	$ 5,777
Annuities
Segment Reporting Information [Line Items]
DAC and VOBA	4,819	4,820
Life
Segment Reporting Information [Line Items]
DAC and VOBA	671	787
Run-off
Segment Reporting Information [Line Items]
DAC and VOBA	5	584
Corporate & Other
Segment Reporting Information [Line Items]
DAC and VOBA	$ 128	$ 148