Accumulated Other Comprehensive Income (Changes In Components Of AOCI) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	$ 56
Accumulated Other Comprehensive Income, Other comprehensive income before reclassifications	(31)
Accumulated Other Comprehensive Income, Amounts reclassified from AOCI	(16)
Accumulated Other Comprehensive Income, Net current period other comprehensive income	(47)	150
Accumulated Other Comprehensive Income, Ending Balance	9
Foreign Currency Translation, Net, Net current period other comprehensive income	(43)	(12)
Foreign Currency Translation, Net [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Foreign Currency Translation, Net, Beginning Balance	13
Foreign Currency Translation, Net, Other comprehensive income before reclassifications	(43)
Foreign Currency Translation, Net, Amounts reclassified from AOCI
Foreign Currency Translation, Net, Net current period other comprehensive income	(43)
Foreign Currency Translation, Net, Ending Balance	(30)
Unrealized gains (losses) on AFS [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Unrealized Gains (Losses) on AFS Securities, Net, Beginning Balance	43
Unrealized Gains (Losses) on AFS Securities, Net, Other comprehensive income before reclassifications	12
Unrealized Gains (Losses) on AFS Securities, Net, Amounts reclassified from AOCI	(16)
Accumulated Other Comprehensive Income, Net current period other comprehensive income	(4)
Unrealized Gains (Losses) on AFS Securities, Net, Ending Balance	$ 39