Activity Presented in Consolidated Statement of Income Related to Consolidated Securitization Entities (Detail) - USD ($) $ in Millions		3 Months Ended																12 Months Ended
		Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Variable Interest Entity [Line Items]
Net investment income																		$ 3,138	$ 3,142	$ 3,155
Derivatives	[1]																	(76)	(103)	(49)
Total net investment gains (losses)	[2]																	5	16	69
Total revenues		$ 2,156	[3]	$ 2,100	[3]	$ 2,157	[3]	$ 2,135	[3]	$ 2,229		$ 2,190		$ 2,194		$ 2,116		8,548	8,729	8,625
Interest expense																		419	433	450
Income before income taxes																		(15)	(1,299)	993
Provision for income taxes																		(9)	(94)	313
Net income		$ (240)	[4],[5]	$ (238)	[4],[5]	$ (139)	[4],[5]	$ 204	[4],[5]	$ (708)	[6]	$ (787)	[6]	$ 228	[6]	$ 219	[6]	(413)	(1,048)	714
Securitization entities
Variable Interest Entity [Line Items]
Restricted commercial mortgage loans																		14	14	23
Restricted other invested assets																		5	5	4
Net investment income																		19	19	27
Trading securities																		(2)	15	(4)
Derivatives																		3	10	86
Borrowings related to securitization entities recorded at fair value																		4	(9)	(13)
Total net investment gains (losses)																		5	16	69
Total revenues																		24	35	96
Interest expense																		9	10	16
Total expenses																		9	10	16
Income before income taxes																		15	25	80
Provision for income taxes																		5	9	27
Net income																		$ 10	$ 16	$ 53

[1] See note 5 for additional information on the impact of derivative instruments included in net investment gains (losses).

[2] See note 17 for additional information related to consolidated securitization entities.

[3] We completed our annual review of assumptions in the fourth quarter of 2015, which primarily resulted in $12 million of higher revenue, which included $5 million of corrections related to reinsurance inputs, in our universal and term universal life insurance products. The updated assumptions reflected changes to persistency, long-term interest rates, mortality and other refinements.

[4] We completed our annual review of assumptions in the fourth quarter of 2015, which primarily resulted in $194 million, net of taxes, of charges, which included $36 million, net of taxes, of corrections related to reinsurance inputs, in our universal and term universal life insurance products. We also recorded an expected loss of $134 million, net of taxes, related to the planned sale of our mortgage insurance business in Europe in the fourth quarter of 2015.

[5] We completed the sale of our lifestyle protection insurance business on December 1, 2015 and recorded an additional loss of $63 million, net of taxes, in the fourth quarter of 2015. The additional loss in the fourth quarter of 2015 was primarily related to the write off of currency translation adjustments on a holding company that was not part of the sale but related to our lifestyle protection insurance business that was substantially liquidated after the completion of the sale.

[6] During the fourth quarter of 2014, we completed our annual loss recognition testing of our long-term care insurance business which resulted in additional charges of $478 million, net of taxes. During the fourth quarter of 2014, we also recorded goodwill impairments of $274 million, net of taxes, in our U.S. Life Insurance segment. There was $205 million net tax impact in the fourth quarter of 2014 from potential business portfolio changes. We recognized a tax charge of $174 million in the fourth quarter of 2014 associated with our Australian mortgage insurance business as we can no longer assert our intent to permanently reinvest earnings in that business. In addition, in connection with our plans to sell our lifestyle protection insurance business, we made a change to the permanent reinvestment assertion of one of its legal entities recognizing tax expense of $31 million in the fourth quarter of 2014. We recorded a correction of $32 million, net of taxes, in our life insurance business related to reserves on a reinsurance transaction in the fourth quarter of 2014. Our long-term care insurance claim reserves also increased in the fourth quarter of 2014 as a result of a $44 million unfavorable correction related to claims in course of settlement arising in connection with the implementation of our updated assumptions and methodologies as part of our comprehensive claims review completed in the third quarter of 2014, partially offset by a $28 million favorable refinement of assumptions for claim termination rates.