CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property-liability insurance premiums earned	$ 1,296	$ 1,338	$ 1,446
Property-liability insurance claims and claims expense
Reinsurance ceded amount	1,116	602	1,393
Life and annuity contract benefits
Reinsurance ceded amount	208	219	356
Interest credited to contractholder funds
Reinsurance ceded amount	26	25	26
Property-liability insurance premiums earned
Property-liability insurance premiums earned	987	1,006	1,030
Life and annuity premiums and contract charges
Life and annuity premiums and contract charges	$ 309	$ 332	$ 416

Amount of earned premiums ceded to other entities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.1)
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 50
-Paragraph 1
-Subparagraph (b),(c)(2)
-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6486662&loc=d3e27175-158546

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 235
-Section S99
-Paragraph 2
-Subparagraph (SX 210.12-17)
-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

Name:	us-gaap_CededPremiumsEarned
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration