Reinsurance (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Insurance [Abstract]
Life insurance recoveries on ceded reinsurance contracts	$ 302	$ 252	$ 324
Premium income subject to participation through reinsurance, percentage	31.00%
Ceded premiums written	94	106	129
Ceded premiums written, accident and health	177	191	205
Reinsurance effect on claims and benefits incurred, amount ceded	$ 67	$ 71	$ 56

Premiums assumed for all accident and health insurance contracts by another insurer as a result of reinsurance arrangements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

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 Statement of Financial Accounting Standard (FAS)

-Number 113

-Paragraph 27

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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