Investments (Details Textuals 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Investments [Abstract]
Financing Receivable, Significant Purchases	$ 205	$ 64

The amount of any significant purchases of financing receivables during the reporting period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953423-111524

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