Accumulated Other Comprehensive Income (Changes In The Components Of AOCI) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Beginning balance			$ (61)
Other comprehensive income (loss) before reclassification			91
Amounts reclassified from AOCI			5
Total other comprehensive income (loss)	$ (23)	$ 26	96	$ (31)
Ending balance	35		35
Unrealized gains (losses) on AFS, net [Member]
Beginning balance			(22)
Other comprehensive income (loss) before reclassification			137
Amounts reclassified from AOCI			5
Total other comprehensive income (loss)			142
Ending balance	120		120
Foreign currency translation, net [Member]
Beginning balance			(39)
Other comprehensive income (loss) before reclassification			(46)
Amounts reclassified from AOCI			0
Total other comprehensive income (loss)			(46)
Ending balance	$ (85)		$ (85)