Shareholders' Equity (Accumulated Other Comprehensive Income by Component) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance			$ 360
Other comprehensive income (loss) before reclassifications			(899)
Amounts reclassified out of AOCI			16
Other comprehensive income (loss)	(774)	(238)	(883)	122
AOCI net of tax, ending balance	(523)		(523)
Net Unrealized Gains (Losses) on Cash Flow Hedges
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance			69
Other comprehensive income (loss) before reclassifications			92
Amounts reclassified out of AOCI			2
Other comprehensive income (loss)			94
AOCI net of tax, ending balance	163		163
Net Unrealized Gains (Losses) on Available-for-Sale Securities
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance			519
Other comprehensive income (loss) before reclassifications			(694)
Amounts reclassified out of AOCI			1
Other comprehensive income (loss)			(693)
AOCI net of tax, ending balance	(174)		(174)
Net Unrealized Losses on Hedges of Net Investments in Non-U.S. Subsidiaries
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance			(14)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified out of AOCI			0
Other comprehensive income (loss)			0
AOCI net of tax, ending balance	(14)		(14)
Other-Than-Temporary Impairment on Held-to-Maturity Securities
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance			(65)
Other comprehensive income (loss) before reclassifications			9
Amounts reclassified out of AOCI			2
Other comprehensive income (loss)			11
AOCI net of tax, ending balance	(54)		(54)
Unrealized Losses on Retirement Plans
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance			(283)
Other comprehensive income (loss) before reclassifications			(2)
Amounts reclassified out of AOCI			10
Other comprehensive income (loss)			8
AOCI net of tax, ending balance	(275)		(275)
Foreign Currency Translation
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance			134
Other comprehensive income (loss) before reclassifications			(304)
Amounts reclassified out of AOCI			1
Other comprehensive income (loss)			(303)
AOCI net of tax, ending balance	$ (169)		$ (169)