Accumulated Other Comprehensive Income (Changes In The Components Of AOCI) (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Beginning balance				$ (128)
Other comprehensive income (loss) before reclassification	[1]			142
Amounts reclassified from AOCI				1
Total other comprehensive income (loss)		$ 54	$ (23)	143	$ 96
Ending balance		15		15
Unrealized gains (losses) on AFS, net [Member]
Beginning balance				6
Other comprehensive income (loss) before reclassification				17
Amounts reclassified from AOCI				1
Total other comprehensive income (loss)				18
Ending balance		24		24
Foreign currency translation, net [Member]
Beginning balance				(134)
Other comprehensive income (loss) before reclassification				125
Amounts reclassified from AOCI				0
Total other comprehensive income (loss)				125
Ending balance		$ (9)		$ (9)

[1] Includes items included in the Company's loss calculation to adjust the carrying value of MBIA UK to its fair value less costs to sell for the year ended December 31, 2016. The sale was completed in January of 2017 and as such, these amounts included in AOCI were reversed and included in the Sale Transaction.