Shareholders' Equity (Accumulated Other Comprehensive Income by Component) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance	$ (95)
Other comprehensive income (loss)	283	(109)
AOCI net of tax, ending balance	188
Accumulated Other Comprehensive Income (Loss)
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance	(95)	360
Other comprehensive income (loss) before reclassifications	286	(114)
Amounts reclassified out of AOCI	(3)	5
Other comprehensive income (loss)	283	(109)
AOCI net of tax, ending balance	188	251
Net Unrealized Gains (Losses) on Cash Flow Hedges
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance	161	69
Other comprehensive income (loss) before reclassifications	(8)	63
Amounts reclassified out of AOCI	1	1
Other comprehensive income (loss)	(7)	64
AOCI net of tax, ending balance	154	133
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	(221)	519
Other comprehensive income (loss) before reclassifications	258	69
Amounts reclassified out of AOCI	(9)	(3)
Other comprehensive income (loss)	249	66
AOCI net of tax, ending balance	28	585
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)	(14)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified out of AOCI	0	0
Other comprehensive income (loss)	0	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	(47)	(65)
Other comprehensive income (loss) before reclassifications	8	4
Amounts reclassified out of AOCI	0	2
Other comprehensive income (loss)	8	6
AOCI net of tax, ending balance	(39)	(59)
Net Unrealized Losses on Retirement Plans
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance	(203)	(283)
Other comprehensive income (loss) before reclassifications	1	(2)
Amounts reclassified out of AOCI	5	5
Other comprehensive income (loss)	6	3
AOCI net of tax, ending balance	(197)	(280)
Foreign Currency Translation
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
AOCI net of tax, beginning balance	229	134
Other comprehensive income (loss) before reclassifications	27	(248)
Amounts reclassified out of AOCI	0	0
Other comprehensive income (loss)	27	(248)
AOCI net of tax, ending balance	$ 256	$ (114)