Investments in Securities Other-than-temporary Impairments 1 (Details) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Investments, Debt and Equity Securities [Abstract]
12 Consecutive Months or Longer, Gross Unrealized Losses	$ 2,480,000,000	$ 4,158,000,000
Aggregate Losses in Continuous Unrealized Loss Position	$ 2,500,000,000
Fair value of securities with unrealized losses for 12 consecutive months or longer as percentage of cost basis	85.00%

Amount of the excess of amortized cost basis over fair value of securities in a loss position and categorized neither as held-to-maturity nor trading securities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant