Accumulated Other Comprehensive Income (Changes In The Components Of AOCI) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Beginning balance		$ (128)
Other comprehensive income (loss) before reclassification	[1]	97
Amounts reclassified from AOCI		0
Total other comprehensive income (loss)		97	$ 66
Ending balance		(31)
Unrealized gains (losses) on AFS, net [Member]
Beginning balance		6
Other comprehensive income (loss) before reclassification		(26)
Amounts reclassified from AOCI		0
Total other comprehensive income (loss)		(26)
Ending balance		(20)
Foreign currency translation, net [Member]
Beginning balance		(134)
Other comprehensive income (loss) before reclassification		123
Amounts reclassified from AOCI		0
Total other comprehensive income (loss)		123
Ending balance		$ (11)

[1] Represents 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.