Debt (Principal Payments For Investment Agreements, MTNs and VIE Obligations) (Detail) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Total expected principal payments		$ 582	$ 592
Investment Agreement Obligations [Member]
Debt Instrument [Line Items]
2016		36
2017		55
2018		17
2019		7
2020		37
Thereafter		373
Total expected principal payments	[1]	525
Less discount and other adjustments		63
Total		462
Less unamortized discount		69
Accrued interest		6
Medium Term Notes [Member]
Debt Instrument [Line Items]
2016		112
2017		39
2018		59
2019		55
2020		1
Thereafter		1,098
Total expected principal payments	[2]	1,364
Less discount and other adjustments		348
Total		1,016
Less unamortized discount		296
Fair value adjustments		56
Accrued interest		4
Variable Interest Entity Debt [Member] | International And Structured Finance Insurance [Member]
Debt Instrument [Line Items]
2016		567
2017		516
2018		505
2019		364
2020		314
Thereafter		2,785
Total expected principal payments	[3]	5,051
Net fair value		$ 2,400

[1] Amounts reflect principal due at maturity for presented in investment agreements issued at a discount.

[2] Amounts reflect principal due at maturity for notes issued at a discount or premium.

[3] Includes $2.4 billion of VIE notes accounted for at fair value as of December 31, 2015.