Shareholders' Equity (Accumulated Other Comprehensive Income by Component) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance	$ 360	$ (659)
Other comprehensive income (loss)	(455)	1,019	30
AOCI net of tax, ending balance	(95)	360	(659)
Accumulated Other Comprehensive Income (Loss)
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance	360
Other comprehensive income (loss) before reclassifications	(475)
Amounts reclassified out of AOCI	20
Other comprehensive income (loss)	(455)
AOCI net of tax, ending balance	(95)
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	89
Amounts reclassified out of AOCI	3
Other comprehensive income (loss)	92
AOCI net of tax, ending balance	161
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	(735)
Amounts reclassified out of AOCI	(5)
Other comprehensive income (loss)	(740)
AOCI net of tax, ending balance	(221)
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)
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	15
Amounts reclassified out of AOCI	3
Other comprehensive income (loss)	18
AOCI net of tax, ending balance	(47)
Net 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	60
Amounts reclassified out of AOCI	20
Other comprehensive income (loss)	80
AOCI net of tax, ending balance	(203)
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	96
Amounts reclassified out of AOCI	(1)
Other comprehensive income (loss)	95
AOCI net of tax, ending balance	$ 229