Investments in Securities Accumulated Other Comprehensive Income 1 (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Net unrealized gains on available-for-sale securities for which we have not recorded other-than-temporary impairment, net of tax	$ 1,399	$ 1,152	$ 304	[1]
Net unrealized losses on available-for-sale securities for which we have recorded other-than-temporary impairment, net of tax	(465)	(1,953)	(1,736)	[1]
Prior service cost and actuarial gains, net of amortization for defined benefit plans, net of tax	(505)	(389)	(214)	[1]
Other losses	(45)	(45)	(36)	[1]
Accumulated other comprehensive income (loss)	384	(1,235)	(1,682)	[1]
Consolidation Acounting Guidance Adopted on January 1, 2010 [Member]
Schedule of Available-for-sale Securities [Line Items]
Accumulated other comprehensive income (loss)			$ 3,400

[1] Includes a net increase of $3.4 billion from the adoption of the consolidation accounting guidance.