Nationwide Life Insurance (NWLIC) POS AM 27 Mar 15 Prospectus update (post-effective amendment) Financial data

Document_and_Entity_Informatio

Document and Entity Information	12 Months Ended
	Dec. 31, 2014
Document Information [Line Items]
Document Type	POS AM
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Trading Symbol	NWLIC
Entity Registrant Name	NATIONWIDE LIFE INSURANCE CO
Entity Central Index Key	205695
Entity Filer Category	Non-accelerated Filer

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues
Policy charges	$2,065	$1,849	$1,670
Premiums	831	724	635
Net investment income	1,900	1,849	1,825
Net realized investment (losses) gains, including other-than-temporary impairment losses	-1,078	678	319
Other revenues	11	17	7
Total revenues	3,729	5,117	4,456
Benefits and expenses
Interest credited to policyholder account values	1,096	1,067	1,038
Benefits and claims	1,502	1,354	1,227
Amortization of deferred policy acquisition costs	207	374	575
Other expenses, net of deferrals	1,055	981	917
Total benefits and expenses	3,860	3,776	3,757
(Loss) income before federal income taxes and noncontrolling interests	-131	1,341	699
Federal income tax (benefit) expense	-147	313	99
Net income	16	1,028	600
Less: Loss attributable to noncontrolling interest, net of tax	-94	-82	-61
Net income attributable to Nationwide Life Insurance Company	$110	$1,110	$661

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income	$16	$1,028	$600
Other comprehensive income (loss), net of tax
Net unrealized gains (losses) on available-for-sale securities	435	-663	571
Other	27	-7	-5
Total other comprehensive income (loss), net of tax	462	-670	566
Total comprehensive income	478	358	1,166
Less: Comprehensive loss attributable to noncontrolling interests, net of tax	-94	-82	-61
Total comprehensive income attributable to Nationwide Life Insurance Company	$572	$440	$1,227

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Assets
Fixed maturity securities, available-for-sale	$35,418		$32,249
Mortgage loans, net of allowance	7,270		6,341
Policy loans	992		987
Short-term investments	935		411
Other investments	822		767
Total investments	45,437		40,755
Cash and cash equivalents	77		61
Accrued investment income	670		603
Deferred policy acquisition costs	4,063		3,778
Goodwill	200	[1]	200	[1]
Other assets	5,001		3,979
Separate account assets	88,076		84,069
Total assets	143,524		133,445
Liabilities
Future policy benefits and claims	40,730		36,765
Short-term debt	660		278
Long-term debt	709		707
Other liabilities	5,313		4,122
Separate account liabilities	88,076		84,069
Total liabilities	135,488		125,941
Shareholder's equity
Common stock value	4		4
Additional paid-in capital	1,718		1,718
Retained earnings	4,630		4,520
Accumulated other comprehensive income	1,044		582
Total shareholder's equity	7,396		6,824
Noncontrolling interests	640		680
Total equity	8,036		7,504
Total liabilities and equity	$143,524		$133,445
[1]	The goodwill balances have not been previously impaired.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Common stock, par value	$1	$1
Common stock, shares authorized	5,000,000	5,000,000
Common stock, shares issued	3,814,779	3,814,779
Common stock, shares outstanding	3,814,779	3,814,779

Consolidated_Statements_of_Equ

Consolidated Statements of Equity (USD $)	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)	Total shareholder's equity	Non-controlling interest
In Millions, unless otherwise specified
Beginning Balance at Dec. 31, 2011	$5,542	$4	$1,718	$2,789	$686	$5,197	$345
Cash dividend paid	-40			-40		-40
Comprehensive income (loss):
Net income (loss)	600			661		661	-61
Other comprehensive income	566				566	566
Total comprehensive income	1,166			661	566	1,227	-61
Change in noncontrolling interest	63						63
Ending Balance at Dec. 31, 2012	6,731	4	1,718	3,410	1,252	6,384	347
Comprehensive income (loss):
Net income (loss)	1,028			1,110		1,110	-82
Other comprehensive income	-670				-670	-670
Total comprehensive income	358			1,110	-670	440	-82
Change in noncontrolling interest	415						415
Ending Balance at Dec. 31, 2013	7,504	4	1,718	4,520	582	6,824	680
Comprehensive income (loss):
Net income (loss)	16			110		110	-94
Other comprehensive income	462				462	462
Total comprehensive income	478			110	462	572	-94
Change in noncontrolling interest	54						54
Ending Balance at Dec. 31, 2014	$8,036	$4	$1,718	$4,630	$1,044	$7,396	$640

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities
Net income	$16	$1,028	$600
Adjustments to net income:
Net realized investment losses (gains), including other-than-temporary impairment losses	1,078	-678	-319
Interest credited to policyholder account values	1,096	1,067	1,038
Capitalization of deferred policy acquisition costs	-685	-604	-470
Amortization of deferred policy acquisition costs	207	374	575
Amortization and depreciation	128	77	80
Deferred tax (benefit) expense	-152	346	243
Changes in:
Policy liabilities	-421	-475	-548
Derivatives, net	-181	-483	-490
Other, net	-59	88	-84
Net cash provided by operating activities	1,027	740	625
Cash flows from investing activities
Proceeds from maturities of available-for-sale securities	2,798	3,689	2,909
Proceeds from sales of available-for-sale securities	647	1,091	796
Purchases of available-for-sale securities	-5,640	-6,842	-5,167
Proceeds from repayments and sales of mortgage loans	920	1,091	1,048
Issuances and purchases of mortgage loans	-1,837	-1,593	-1,114
Net (increase) decrease in short-term investments	-524	654	98
Collateral received (paid), net	399	-637	-208
Other, net	-94	42	-12
Net cash used in investing activities	-3,331	-2,505	-1,650
Cash flows from financing activities
Net change in short-term debt	382	-22	-477
Proceeds from issuance of long-term debt		2	13
Cash dividend paid to Nationwide Financial Services, Inc.			-40
Repayments of long-term debt		-299
Investment and universal life insurance product deposits	6,037	6,139	5,566
Investment and universal life insurance product withdrawals	-4,095	-4,034	-4,063
Other, net	-4	-22	39
Net cash provided by financing activities	2,320	1,764	1,038
Net increase (decrease) in cash and cash equivalents	16	-1	13
Cash and cash equivalents at beginning of year	61	62	49
Cash and cash equivalents at end of year	$77	$61	$62

Nature_of_Operations

Nature of Operations	12 Months Ended
	Dec. 31, 2014
Nature of Operations	-1	Nature of Operations
	Nationwide Life Insurance Company (“NLIC,” or collectively with its subsidiaries, “the Company”) was incorporated in 1929 and is an Ohio domiciled stock life insurance company. The Company is a member of the Nationwide group of companies (“Nationwide”), which is comprised of Nationwide Mutual Insurance Company (“NMIC”) and all of its subsidiaries and affiliates.
	All of the outstanding shares of NLIC’s common stock are owned by Nationwide Financial Services, Inc. (“NFS”), a holding company formed by Nationwide Corporation (“Nationwide Corp.”), a majority-owned subsidiary of NMIC.
	The Company is a leading provider of long-term savings and retirement products in the United States of America (“U.S.”). The Company develops and sells a diverse range of products and services including individual annuities, private and public sector group retirement plans, investment products sold to institutions, life insurance and advisory services.
	The Company sells its products through a diverse distribution network. Unaffiliated entities that sell the Company’s products to their own customer bases include independent broker-dealers, financial institutions, wirehouse and regional firms, pension plan administrators and life insurance specialists. Representatives of affiliates who market products directly to a customer base include Nationwide Retirement Solutions, Inc. (“NRS”) and Nationwide Financial Network (“NFN”) producers, which includes the agency distribution force of the Company’s ultimate parent company, NMIC.
	Wholly-owned subsidiaries of NLIC as of December 31, 2014 include Nationwide Life and Annuity Insurance Company (“NLAIC”), Nationwide Investment Services Corporation (“NISC”) and Nationwide Investment Advisor (“NIA”). NLAIC primarily offers universal life insurance, variable universal life insurance, term life insurance, corporate-owned life insurance (“COLI”) and individual annuity contracts on a non-participating basis. NISC is a registered broker-dealer. NIA is a registered investment advisor.
	As of December 31, 2014 and 2013, the Company did not have a significant concentration of financial instruments in a single investee, industry or geographic region of the U.S. Also, the Company did not have a concentration of business transactions with a particular customer, lender, distribution source, market or geographic region of the U.S. in which the Company is overly vulnerable to a single event which could cause a severe impact on the Company’s financial position.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies	-2	Summary of Significant Accounting Policies
	Basis of Presentation
	The consolidated financial statements include the accounts of NLIC and companies in which NLIC directly or indirectly has a controlling financial interest. The consolidated financial statements include majority-owned subsidiaries and consolidated variable interest entities (“VIEs”). All significant intercompany accounts and transactions have been eliminated.
	Entities in which NLIC does not have a controlling interest, but the Company has significant influence over the operating and financing decisions, and also certain other investments, are reported using the equity method.
	Use of Estimates
	The Company’s consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”). The preparation of the consolidated financial statements in accordance with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Significant estimates include the balance and amortization of deferred policy acquisition costs (“DAC”), legal and regulatory reserves, certain investment and derivative valuations, future policy benefits and claims including the valuation of embedded derivatives resulting from living benefit guarantees on variable annuity contracts, goodwill, provision for income taxes and valuation of deferred tax assets. Actual results could differ significantly from those estimates.
	Revenues and Benefits
	Investment and universal life insurance products. Investment products are long-duration contracts that do not subject the Company to significant risk arising from mortality (the incidence of death) or morbidity (the incidence of disability resulting from disease or physical impairment). These include variable and fixed deferred annuity contracts in the accumulation phase with both individuals and groups, as well as certain annuities without life contingencies. Universal life insurance products include long-duration insurance contracts that do not have fixed or guaranteed terms. These include universal life insurance, variable universal life insurance, COLI, bank-owned life insurance (“BOLI”) and other interest-sensitive life insurance policies. Revenues for investment products and universal life insurance products consist of net investment income, surrender charges and other policy charges earned and assessed against policy account balances during the period. Policy charges are assessed on a daily or monthly basis and are recognized as revenue when assessed and earned. Assessments for services provided in future periods are recorded as unearned revenue and recognized as revenue over the periods benefited. Surrender charges are recognized as revenue upon surrender of a contract in accordance with contractual terms. Policy benefits and claims that are charged to expense include interest credited to policyholder accounts and benefits and claims incurred in the period in excess of related policyholder accounts.
	Traditional life insurance products. Traditional life insurance products include those products with fixed and guaranteed terms, primarily consisting of whole life insurance, term life insurance and certain annuities with life contingencies. Premiums for traditional life insurance products are generally recognized as revenue when due. For certain annuities with life contingencies, any excess of gross premium over the net premium is deferred and recognized with the amount of expected future benefits. Benefits and expenses are associated with earned premiums so that profits are recognized over the life of the contract. This association is accomplished through the provision for future policy benefits and the deferral and amortization of policy acquisition costs.
	Future Policy Benefits and Claims
	Investment and universal life insurance products. The Company calculates its liability for future policy benefits and claims for investment products in the accumulation phase and for universal life insurance policies at the policy accrued account balance, which represents participants’ net deposits adjusted for investment performance, interest credited and applicable contract charges.
	The Company offers certain universal life insurance and variable universal life insurance with no-lapse guarantees and variable annuity products with guaranteed minimum death benefits (“GMDB”) and/or guaranteed minimum income benefits (“GMIB”). Liabilities for these guarantees are calculated by multiplying the current benefit ratio by the cumulative assessments recorded from contract inception through the balance sheet date less the cumulative guaranteed benefit payments plus interest. The Company annually evaluates its experience and assumptions and adjusts the benefit ratio as appropriate. If experience or assumption changes result in a new benefit ratio, the reserves are adjusted to reflect the changes with a related charge or credit to other benefits and claims in the period of evaluation. Determination of the expected benefit payments and assessments are based on a range of scenarios and assumptions, including those related to market rates of return and volatility, contract surrenders and mortality experience. The accounting for these guarantees impacts estimated gross profits used to calculate the balance and amortization of DAC and other expenses. Refer to Note 4 for further discussion of these guarantees.
	Guarantees to variable annuity contractholders can include a return of no less than the total deposits made on the contract less any customer withdrawals, total deposits made on the contract less any customer withdrawals plus a minimum return, or the highest contract value on a specified anniversary date minus any customer withdrawals following the contract anniversary. In addition, these guarantees can include benefits payable in the event of death, upon annuitization, upon periodic withdrawal or at specified dates during the accumulation period. Refer to Note 4 for further discussion of these guarantees.
	The Company’s guaranteed minimum accumulation benefit (“GMAB”) and guaranteed living withdrawal benefit (“GLWB”) living benefit guarantees represent embedded derivatives in variable annuity contracts that are required to be separated from, and valued apart from, the host variable annuity contracts. The embedded derivatives are held at fair value and include the present value of attributed fees. Subsequent changes in the fair value of the embedded derivatives are recognized in earnings as a component of net realized investment gains and losses. The fair value of the embedded derivatives is calculated based on a combination of capital market and actuarial assumptions. Projections of cash flows inherent in the valuation of the embedded derivatives incorporate numerous assumptions including, but not limited to, mortality, lapse rates, index volatility, benefit utilization and discounting. Benefit utilization includes wait period (the number of years the policyholder is assumed to wait prior to beginning withdrawals once eligible) and efficiency of benefit utilization (the percent of the maximum permitted withdrawal that a policyholder takes). Discounting includes liquidity and non-performance risk (the risk that the liability will not be fulfilled) and affects the value at which the liability is transferred. The assumptions used to calculate the fair value of embedded derivatives are reviewed as part of an annual comprehensive study of assumptions. Quarterly, consideration is given as to whether adjustments to these assumptions are necessary.
	The Company’s equity indexed products (life and annuity) have the policyholders’ interest credits based on market performance with caps and floors. The interest credits represent embedded derivatives within the insurance contract and therefore are required to be separated from, and valued apart from, the host contracts. The embedded derivatives are held at fair value. Subsequent changes in the fair value of the embedded derivatives are recognized in earnings as a component of interest credited. The fair value of the embedded derivatives is calculated based on a combination of capital market and actuarial assumptions. Projections of cash flows inherent in the valuation of the embedded derivative incorporate numerous assumptions including, but not limited to, mortality, lapse rates and index volatility. The assumptions used to calculate the fair value of embedded derivatives are reviewed as part of an annual comprehensive study of assumptions. Quarterly, consideration is given as to whether adjustments to these assumptions are necessary.
	Traditional life insurance products. The process of calculating reserve amounts for traditional life insurance products involves the use of a number of assumptions, including those related to persistency, mortality, morbidity, interest rates (the rates expected to be paid or received on financial instruments) and certain other expenses.
	The liability for future policy benefits and claims for traditional life insurance policies was determined using the net level premium method, with weighted average interest rates of 6.6% and estimates of mortality, morbidity, investment yields and persistency that were used or being experienced at the time the policies were issued, with a provision for adverse deviation.
	The liability for future policy benefits for certain annuities with life contingencies was calculated using the present value of future benefits and certain expenses, discounted using weighted average interest rates of 4.8% with a provision for adverse deviation.
	The Company issues fixed and floating rate funding agreements to the Federal Home Loan Bank of Cincinnati (“FHLB”). The liability for such funding agreements is recorded in future policy benefits and claims at amortized cost. The amount of collateralized funding agreements outstanding with the FHLB as of December 31, 2014 and 2013 was $1.8 billion and $913 million, respectively. In connection with an FHLB requirement for funding agreements, the Company held $35 million and $18 million of FHLB stock as of December 31, 2014 and 2013, respectively.
	Reinsurance ceded
	The Company cedes insurance to other companies in order to limit potential losses and to diversify its exposures. Such agreements do not relieve the original insurer from its primary obligation to the policyholder in the event the reinsurer is unable to meet the obligations it has assumed. Reinsurance premiums ceded and reinsurance recoveries on benefits and claims incurred are deducted from the respective income and expense accounts. Assets and liabilities related to reinsurance ceded are reported in the consolidated balance sheets on a gross basis, separately from the related future policy benefits and claims of the Company.
	Deferred Policy Acquisition Costs
	The Company has deferred certain acquisition costs that are directly related to the successful acquisition of new and renewal insurance and investment contracts. The methods and assumptions used to amortize and assess recoverability of the DAC balance depend on the type of product.
	Investment and universal life insurance products. For certain investment and universal life insurance products, DAC is amortized with interest over the lives of the policies in relation to the present value of estimated gross profits, which is determined primarily from projected interest margins, policy charges and net realized investment gains and losses, less policy benefits and other expenses. The DAC asset related to investment and universal life insurance products is adjusted to reflect the impact of unrealized gains and losses on available-for-sale securities, with the corresponding adjustment recorded in accumulated other comprehensive income (“AOCI”). This adjustment to DAC represents the change in amortization that would have been required as a charge or credit to operations had such unrealized amounts been realized. DAC for investment and universal life insurance products is subject to recoverability testing in the year of policy issuance, and DAC for universal life insurance products is also subject to loss recognition testing at the end of each reporting period.
	The Company regularly evaluates and adjusts the DAC balance when actual gross profits in a given reporting period vary from management’s initial estimates. Additionally, the assumptions used in the estimation of gross profits are based on the Company’s current best estimates of future events and are reviewed as part of an annual process. During the annual process, the Company performs a comprehensive study of assumptions, including mortality and persistency studies, maintenance expense studies and an evaluation of projected general and separate account investment returns. The most significant assumptions that are involved in the estimation of future gross profits include future net separate account investment performance, surrender/lapse rates, interest margins, renewal premiums and mortality. The Company refers to this process as “unlocking.” Quarterly, consideration is given as to whether adjustments to these assumptions are necessary. The Company uses a reversion to the mean process to determine the assumption for the future net separate account investment performance. This process assumes different performance levels over the next three years, such that the separate account mean return, measured from the anchor date to the end of the life of the product, equals the long-term assumption. The Company’s long-term assumptions for net separate account investment performance consist of assumed gross returns of 10.5% for equity funds and 5.0% for fixed funds.
	Changes in assumptions and the emergence of actual gross profits can have a significant impact on the amount of DAC reported for investment and universal life insurance products and their related amortization patterns. Additionally, the amortization of DAC can be affected by the change in the valuation of the Company’s variable annuity guarantees. See Future Policy Benefits and Claims for further discussion of the valuation of the Company’s variable annuity guarantees. In the event actual experience differs from assumptions or future assumptions are revised, the Company will record an increase or decrease in DAC amortization expense, which could be significant.
	Traditional life insurance. DAC is amortized with interest over the premium-paying period of the related policies in proportion to premium revenue recognized. These assumptions are consistent with those used in the calculation of liabilities for future policy benefits at issuance. DAC is evaluated for recoverability at the time of policy issuance, and loss recognition testing is conducted each reporting period.
	Refer to Note 5 for discussion regarding assumption changes impacting DAC amortization and related balances.
	Investments
	Available-for-sale securities. Available-for-sale securities are reported at fair value, with unrealized holding gains and losses reported as a separate component of other comprehensive income, net of adjustments for DAC and other expenses, future policy benefits and claims, policyholder dividend obligations and deferred federal income taxes. Realized gains and losses on sales of available-for-sale securities are recognized in income based on the specific identification method. Interest and dividend income is recognized when earned.
	As of December 31, 2014 and 2013, 99% of fixed maturity securities were priced using external source data. Independent pricing services are most often utilized (87% and 86% as of December 31, 2014 and 2013, respectively) to determine the fair value of securities for which market quotations are available. For these securities, the Company obtains the pricing services’ methodologies, inputs and assumptions and classifies the investments accordingly in the fair value hierarchy.
	A corporate pricing matrix is used in valuing certain corporate debt securities. The corporate pricing matrix is developed using private spreads for corporate securities with varying weighted average lives and credit quality ratings. The weighted average life and credit quality rating of a particular fixed maturity security to be priced using the corporate pricing matrix are important inputs into the model and are used to determine a corresponding spread that is added to the appropriate U.S. Treasury yield to create an estimated market yield for that security. The estimated market yield and other relevant factors are then used to estimate the fair value of the particular security.
	Non-binding broker quotes are also utilized to determine the fair value of certain corporate debt, mortgage-backed and other asset-backed securities when quotes are not available from independent pricing services, corporate pricing matrix or internal pricing models. These securities are classified with the lowest priority in the fair value hierarchy as only one broker quote is ordinarily obtained, the investment is not traded on an exchange, the pricing is not available to other entities and/or the transaction volume in the same or similar investments has decreased. Inputs used in the development of prices are not provided to the Company by the brokers, as the brokers often do not provide the necessary transparency into their quotes and methodologies. At least annually, the Company performs reviews and tests to ensure that quotes are a reasonable estimate of the investments’ fair value. Price movements of broker quotes are subject to validation and require approval from the Company’s management. Management uses its knowledge of the investment and current market conditions to determine if the price is indicative of the investment’s fair value.
	When the collectability of contractual interest payments on fixed maturity securities is considered doubtful, such securities are placed in non-accrual status and any accrued interest is excluded from investment income. These securities are not restored to accrual status until the Company determines that payment of future principal and interest is probable.
	For investments in certain residential and commercial mortgage-backed securities, the Company recognizes income and amortizes discounts and premiums using the effective-yield method, based on prepayment assumptions and the estimated economic life of the securities. When actual prepayments differ significantly from estimated prepayments, the effective-yield is recalculated to reflect actual payments to date and anticipated future payments. Any resulting adjustment is included in net investment income in the period the estimates are revised. All other investment income is recorded using the effective-yield method without anticipating the impact of prepayments.
	The Company periodically reviews its available-for-sale securities to determine if any decline in fair value to below amortized cost is other-than-temporary. Factors considered in determining whether a decline is other-than-temporary include the length of time a security has been in an unrealized loss position, the severity of the unrealized loss, reasons for the decline in value and expectations for the amount and timing of a recovery in fair value.
	In assessing corporate debt securities for other-than-temporary impairment, the Company evaluates the ability of the issuer to meet its debt obligations, the value of the company or specific collateral securing the debt, the Company’s intent to sell the security and whether it is more likely than not the Company will be required to sell the security before the recovery of its amortized cost basis. The Company evaluates U.S. government and agencies, as well as obligations of states, political subdivisions and foreign governments for other-than-temporary impairment by examining similar characteristics.
	When evaluating whether residential mortgage-backed securities, commercial mortgage-backed securities and other asset-backed securities are other-than-temporarily impaired, the Company examines characteristics of the underlying collateral, such as delinquency and default rates, the quality of the underlying borrower, the type of collateral in the pool, the vintage year of the collateral, subordination levels within the structure of the collateral pool, the quality of any credit guarantors, the Company’s intent to sell the security and whether it is more likely than not it will be required to sell the security before the recovery of its amortized cost basis.
	The Company evaluates its intent to sell on an individual security basis. Other-than-temporary impairment losses on securities when the Company does not intend to sell the security and it is not more likely than not it will be required to sell the security prior to recovery of the security’s amortized cost basis are bifurcated, with the credit portion of the impairment loss being recognized in earnings and the non-credit loss portion of the impairment and any subsequent changes in the fair value of those debt securities being recognized in other comprehensive income, net of applicable taxes and other offsets. To estimate the credit portion of an impairment loss recognized in earnings, the Company considers the present value of the cash flows. To the extent that the present value of cash flows generated by a debt security is less than the amortized cost, an other-than-temporary impairment is recognized through earnings.
	It is possible that further declines in fair values of such investments, or changes in assumptions or estimates of anticipated recoveries and/or cash flows, may cause further other-than-temporary impairments in the near term, which could be significant.
	Mortgage loans, net of allowance. The Company holds commercial mortgage loans that are collateralized by properties throughout the U.S. These mortgage loans are further segregated into the following classes based on the unique risk profiles of the underlying property types: office, industrial, retail, apartment and other. Mortgage loans held-for-investment are held at amortized cost less a valuation allowance.
	As part of the underwriting process, specific guidelines are followed to ensure the initial quality of a new mortgage loan. Third-party appraisals are generally obtained to support loaned amounts, as the loans are usually collateral dependent.
	The collectability and value of a mortgage loan are based on the ability of the borrower to repay and/or the value of the underlying collateral. Many of the Company’s commercial mortgage loans are structured with balloon payment maturities, exposing the Company to risks associated with the borrowers’ ability to make the balloon payment or refinance the property.
	The Company actively monitors the credit quality of its mortgage loans to support the development of the valuation allowance. This monitoring process includes quantitative analyses, which facilitate the identification of deteriorating loans, and qualitative analyses, which consider other factors relevant to the borrowers’ ability to repay. Surveillance procedures identify loans with deteriorating credit fundamentals and these loans are evaluated based on the severity of their deterioration and management’s judgment as to the likelihood of loss.
	Mortgage loans require a loan-specific reserve when, based on current information and events, it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. When management determines that a loan requires a loan-specific reserve, a provision for loss is established equal to the difference between the carrying value and either the fair value of the collateral less costs to sell or the present value of expected future cash flows discounted at the loan’s market interest rate. Loan-specific reserve charges are recorded in net realized investment gains and losses. In the event a loan-specific reserve charge is reversed, the recovery is also recorded in net realized investment gains and losses.
	In addition to the loan-specific reserves, the Company maintains a non-specific reserve based primarily on loan surveillance categories and property type classes, which reflects management’s best estimate of probable credit losses inherent in the portfolio of loans without specific reserves as of the balance sheet date. Management’s periodic evaluation of the adequacy of the non-specific reserve is based on past loan loss experience, known and inherent risks in the portfolio, adverse situations that may affect a borrower’s ability to repay, the estimated value of the underlying collateral, composition of the loan portfolio, current economic conditions and other relevant factors. Non-specific reserve changes are recorded in net realized investment gains and losses.
	Interest income on performing mortgage loans is recognized over the life of the loan using the effective-yield method. Loans in default or in the process of foreclosure are placed on non-accrual status. Interest received on non-accrual status mortgage loans is included in net investment income in the period received. Loans are considered delinquent when contractual payments are 90 days past due.
	Policy loans. Policy loans, which are collateralized by the related insurance policy, are held at the outstanding principal balance and do not exceed the net cash surrender value of the policy. As such, no valuation allowance for policy loans is required.
	Short-term investments. Short-term investments consist primarily of highly liquid mutual funds and government agency discount notes with maturities of twelve months or less at acquisition. The Company and various affiliates maintain agreements with Nationwide Cash Management Company (“NCMC”), an affiliate, under which NCMC acts as a common agent in handling the purchase and sale of short-term securities for the respective accounts of the participants. Amounts on deposit with NCMC for the benefit of the Company are included in short-term investments on the consolidated balance sheets. The Company carries short-term investments at fair value.
	Other investments. Other investments consist primarily of equity method investments in private equity, hedge funds and partnerships, as well as COLI, trading securities, equity securities and capital stock with the FHLB.
	Securities lending. The Company has entered into securities lending agreements with a custodial bank whereby eligible securities are loaned to third parties, primarily major brokerage firms. These transactions are used to generate additional income on the securities portfolio. The Company is entitled to receive from the borrower any payments of interest and dividends received on loaned securities during the loan term. The agreements require a minimum of 102% of the fair value of loaned securities to be held as collateral. Cash collateral is invested by the custodial bank in investment-grade securities, which are included in the total investments of the Company. Periodically, the Company may receive non-cash collateral, which would be recorded off-balance sheet. The Company recognizes loaned securities in either available-for-sale or other investments. A securities lending payable is recorded in other liabilities for the amount of cash collateral received. Net income received from securities lending activities is included in net investment income. As of December 31, 2014 and 2013, the fair value of loaned securities was $254 million and $116 million, respectively.
	Variable interest entities. In the normal course of business, the Company has relationships with VIEs. If the Company determines that it has a variable interest and is the primary beneficiary, it consolidates the VIE. The Company is the primary beneficiary if the Company has the power to direct the activities of the VIE that most significantly impact the economic performance of the entity and the obligation to absorb losses or receive benefits from the entity that could be potentially significant to the VIE. This determination is based on a review of the entity’s contract and other deal related information, such as the entity’s equity investment at risk, decision-making abilities, obligations to absorb economic risks and right to receive economic rewards of the entity.
	The majority of the VIEs consolidated by the Company are due to guarantees provided to limited partners related to the amount of tax credits that will be generated by Low-Income-Housing Tax Credit Funds (“Tax Credit Funds”). The results of operations and financial position of each VIE for which the Company is the primary beneficiary, as well as the corresponding noncontrolling interests, are recorded in the consolidated financial statements. Ownership interests held by unrelated third parties in the consolidated VIEs are presented as noncontrolling interests in the equity section of the consolidated financial statements. Losses attributable to noncontrolling interests are excluded from the net income attributable to NLIC on the consolidated statements of operations.
	The Company invests in fixed maturity securities that could qualify as VIEs, including corporate securities, mortgage-backed securities and asset-backed securities. The Company is not the primary beneficiary of these securities as the Company does not have the power to direct the activities that most significantly impact the entities’ performance. The Company’s maximum exposure to loss is limited to the carrying values of these securities. There are no liquidity arrangements, guarantees or other commitments by third parties that affect the fair value of the Company’s interest in these assets. Refer to Note 6 for additional disclosures related to these investments.
	The Company is not required and does not intend to provide financial or other support outside of contractual requirements to any VIE.
	Derivative Instruments
	The Company uses derivative instruments to manage exposures and mitigate risks primarily associated with interest rates, equity markets and foreign currency. These derivative instruments primarily include interest rate swaps, futures contracts and options. Certain features embedded in the Company’s indexed products and certain variable annuity contracts require derivative accounting. Refer to the prior discussion of Future Policy Benefits and Claims for a description of the valuation applicable to these products. All derivative instruments are held at fair value and are reflected as assets or liabilities in the consolidated balance sheets.
	The fair value of derivative instruments is determined using various valuation techniques relying predominantly on observable market inputs. These inputs include interest rate swap curves, credit spreads, interest rates, counterparty credit risk, equity volatility and equity index levels. In cases where observable inputs are not available, the Company will utilize non-binding broker quotes to determine fair value, and these instruments are classified accordingly in the fair value hierarchy. Price movements of these broker quotes are subject to validation and require approval from the Company’s management. Management uses models to internally value the instruments for comparison to the values received through broker quotes.
	For derivatives that are not designated for hedge accounting, the gain or loss on the derivative is primarily recognized in net realized investment gains and losses.
	For derivative instruments that are designated and qualify for fair value hedge accounting, the gain or loss on the derivative instrument, as well as the hedged item to the extent of the risk being hedged, are recognized in net realized investment gains and losses.
	For derivative instruments that are designated and qualify for cash flow hedge accounting, the effective portion of the gain or loss on the derivative instrument is reported as a component of AOCI and reclassified into earnings in the same period or periods that the hedged transaction impacts earnings. The ineffective portion of the derivative’s change in value, if any, along with any of the derivative’s change in value that is excluded from the assessment of hedge effectiveness, are recorded in net realized investment gains and losses.
	The Company’s derivative transaction counterparties are generally financial institutions. To reduce the credit risk associated with open contracts, the Company enters into master netting agreements, which permit the closeout and netting of transactions with the same counterparty upon the occurrence of certain events. In addition, the Company attempts to reduce credit risk by obtaining collateral from counterparties. The determination of the need for and the levels of collateral vary based on an assessment of the credit risk of the counterparty. The Company accepts collateral in the form of cash and marketable securities.
	Fair Value Measurements
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements are based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s view of market assumptions in the absence of observable market information. The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. In determining fair value, the Company uses various methods, including market and income approaches.
The Company categorizes its financial instruments into a three-level hierarchy based on the priority of the inputs to the valuation technique. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). If the inputs used to measure fair value fall within different levels of the hierarchy, the category level is based on the lowest priority level input that is significant to the fair value measurement of the instrument in its entirety.
The Company categorizes assets and liabilities held at fair value in the consolidated balance sheets as follows:
Level 1. Unadjusted quoted prices accessible in active markets for identical assets or liabilities at the measurement date and mutual funds where the value per share (unit) is determined and published daily and is the basis for current transactions.
Level 2. Unadjusted quoted prices for similar assets or liabilities in active markets or inputs (other than quoted prices) that are observable or that are derived principally from or corroborated by observable market data through correlation or other means. Primary inputs to this valuation technique may include comparative trades, bid/asks, interest rate movements, U.S. Treasury rates, London Interbank Offered Rate (“LIBOR”), prime rates, cash flows, maturity dates, call ability, estimated prepayments, and/or underlying collateral values.
Level 3. Prices or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement. Inputs reflect management’s best estimate about the assumptions market participants would use at the measurement date in pricing the asset or liability. Consideration is given to the risk inherent in both the method of valuation and the valuation inputs.
The Company reviews its fair value hierarchy classifications for assets and liabilities quarterly. Changes in the observability of significant valuation inputs identified during these reviews may trigger reclassifications. Reclassifications are reported as transfers at the beginning of the period in which the change occurs.
Fair Value Option
The Company assesses the fair value option election for newly acquired assets or liabilities on a prospective basis. There are no material assets or liabilities for which the Company has elected the fair value option.
Federal Income Taxes
The Company recognizes deferred tax assets and liabilities for the expected future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, net operating losses and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income or loss in the years in which those temporary differences are expected to be recovered or settled. Under this method, the effect on deferred tax assets and liabilities due to a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are recorded to reduce a deferred tax asset to the amount expected to be realized. Interest expense and any associated penalties which relate to tax years still subject to review by the Internal Revenue Service (“IRS”) are recorded as income tax expense.
The Company provides for federal income taxes based on amounts the Company believes it ultimately will owe. Inherent in the provision for federal income taxes are estimates regarding the deductibility of certain items and the realization of certain tax credits. In the event the ultimate deductibility of certain items or the realization of certain tax credits differs from estimates, the Company may be required to change the provision for federal income taxes recorded in the consolidated financial statements, which could be significant.
Tax reserves are reviewed regularly and are adjusted as events occur that the Company believes impact its liability for additional taxes, such as the lapsing of applicable statutes of limitations, conclusion of tax audits or substantial agreement with taxing authorities on the deductibility/nondeductibility of uncertain items, additional exposure based on current calculations, identification of new issues, release of administrative guidance or rendering of a court decision affecting a particular tax issue.
NLIC files a separate consolidated federal income tax return with its subsidiaries and is eligible to join the NMIC consolidated tax return group in 2015.
Cash and Cash Equivalents
Cash and cash equivalents include highly liquid investments with original maturities of less than three months.
Goodwill
In connection with business acquisitions, the Company recognizes goodwill as the excess of the purchase price over the fair value of net assets acquired as goodwill. Goodwill is not amortized, but is evaluated for impairment at the reporting unit level annually. Goodwill of a reporting unit is tested for impairment on an interim basis, in addition to the annual evaluation, if an event occurs or circumstances change which would more likely than not reduce the fair value of a reporting unit below its carrying amount. If a reporting unit’s fair value is less than its carrying value, the Company will calculate implied goodwill. An impairment would be recognized on a reporting unit for the amount that the carrying value of its goodwill exceeds the implied value of its goodwill.
The process of evaluating goodwill for impairment requires several judgments and assumptions to be made to determine the fair value of the reporting units, including the method used to determine fair value, discount rates, expected levels of cash flows, revenues and earnings, and the selection of comparable companies used to develop market-based assumptions. The Company performed its 2014 annual impairment test and determined that no impairment was required.
Closed Block
In connection with the sponsored demutualization of Provident Mutual Life Insurance Company (“Provident”) prior to its acquisition by the Company, Provident established a closed block for the benefit of certain classes of individual participating policies that had a dividend scale payable in 2001. Assets were allocated to the closed block in an amount that produces cash flows which, together with anticipated revenues from closed block business, is reasonably expected to be sufficient to provide for (1) payment of policy benefits, specified expenses and taxes, and (2) the continuation of dividends throughout the life of the Provident policies included in the closed block based upon the dividend scales payable for 2001, if the experience underlying such dividend scales continues.
Assets allocated to the closed block benefit only the holders of the policies included in the closed block and will not revert to the benefit of the Company. No reallocation, transfer, borrowing or lending of assets can be made between the closed block and other portions of the Company’s general account, any of its separate accounts, or any affiliate of the Company without the approval of the Pennsylvania Insurance Department and Ohio Department of Insurance (“ODI”). The closed block will remain in effect as long as any policy in the closed block is in force.
If, over time, the aggregate performance of the closed block assets and policies is better than was assumed in funding the closed block, dividends to policyholders will increase. If, over time, the aggregate performance of the closed block assets and policies is less favorable than was assumed in the funding, dividends to policyholders could be reduced. If the closed block has insufficient funds to make guaranteed policy benefit payments, such payments will be made from the Company’s assets outside of the closed block, which are general account assets.
The assets and liabilities allocated to the closed block are recorded in the Company’s consolidated financial statements on the same basis as other similar assets and liabilities. The carrying amount of closed block liabilities in excess of the carrying amount of closed block assets at the date Provident was acquired by the Company represents the maximum future earnings from the assets and liabilities designated to the closed block that can be recognized in income, for the benefit of stockholders, over the period the policies in the closed block remain in force.
If actual cumulative earnings exceed expected cumulative earnings, the expected earnings are recognized in income. This is because the excess actual cumulative earnings over expected cumulative earnings, which represents undistributed accumulated earnings attributable to policyholders, is recorded as a policyholder dividend obligation. Therefore, the excess will be paid to closed block policyholders as an additional policyholder dividend expense in the future unless it is otherwise offset by future performance of the closed block that is less favorable than originally expected. If actual cumulative performance is less favorable than expected, actual earnings will be recognized in income.
The principal cash flow items that affect the amount of closed block assets and liabilities are premiums, net investment income, purchases and sales of investments, policyholder benefits, policyholder dividends, premium taxes and income taxes. The principal income and expense items excluded from the closed block are management and maintenance expenses, commissions and net investment income and realized gains and losses on investments held outside of the closed block that support the closed block business, all of which enter into the determination of total gross margins of closed block policies. See Note 10 for further disclosure.
Separate Accounts
Separate account assets and liabilities represent contractholders’ funds that have been legally segregated into accounts with specific investment objectives. In the separate account, investment income and gains and losses on investments accrue directly to, and investment risk is borne by, the contractholder. Separate account assets are primarily comprised of public, privately registered and non-registered mutual funds. Separate account assets are recorded at fair value based on the methodology that would be applicable to the underlying assets. The value of separate account liabilities is set to equal the fair value for separate account assets.
Participating Business
Participating business, which refers to policies that participate in profits through policyholder dividends, represented approximately 4% of the Company’s life insurance in force in 2014 and 2013 and 5% in 2012 and 37% of the number of life insurance policies in force in 2014 (38% in 2013 and 40% in 2012). The provision for policyholder dividends was based on the respective year’s dividend scales and has been included in future policy benefits and claims in the consolidated balance sheets.
Subsequent Events
The Company evaluated subsequent events through February 25, 2015, the date the consolidated financial statements were issued.

Recently_Issued_Accounting_Sta

Recently Issued Accounting Standards	12 Months Ended
	Dec. 31, 2014
Recently Issued Accounting Standards	-3	Recently Issued Accounting Standards
	Adopted Accounting Standards
	On January 1, 2014, the Company adopted ASU 2013-04, which amends existing guidance in ASC 405, Liabilities. The ASU provides guidance for the recognition, measurement and disclosure of obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. The adoption of this guidance had no impact on the Company’s consolidated financial statements.
	On January 1, 2014, the Company adopted ASU 2013-08, which amends existing guidance in ASC 946, Financial Services – Investment Companies. The amended guidance modifies the definition of investment companies and requires new disclosures around the status and operations of investment companies. In addition, the guidance requires an investment company to measure its noncontrolling interests in another investment company at fair value rather than the equity method of accounting. The adoption of this guidance had no impact on the Company’s consolidated financial statements.
	On January 1, 2014, the Company adopted ASU 2013-11, which amends existing guidance in ASC 740, Income Taxes. The amended guidance provides clarification on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss or a tax credit carryforward exists. The adoption of this guidance had no impact on the Company’s consolidated financial statements.
	Pending Accounting Standards
	In January 2014, the FASB issued ASU 2014-01, which amends existing guidance in ASC 323, Equity Method and Joint Ventures. The amended guidance permits reporting entities to make an accounting policy election to account for their investments in qualified affordable housing projects using the proportional amortization method if certain conditions are met. The Company will adopt the ASU for interim and annual reporting periods beginning January 1, 2015. The Company is currently in the process of determining the impact of adoption.
	In January 2014, the FASB issued ASU 2014-04, which amends existing guidance in ASC 310, Receivables and ASC 360, Property, Plant and Equipment. The amended guidance provides clarification on the accounting for situations in which a creditor obtains collateral assets in satisfaction of all or part of a receivable. The Company will adopt the ASU for interim and annual periods beginning January 1, 2015. The Company is currently in the process of determining the impact of adoption.
	In May 2014, the FASB issued ASU 2014-09, which amends existing guidance in ASC 606, Revenue from Contracts with Customers and ASC 340, Other Assets and Deferred Costs – Contracts with Customers. The amended guidance develops a single standard to recognize revenue when the identified performance obligation is satisfied. The Company will adopt the ASU for interim and annual periods beginning January 1, 2017. The Company is currently in the process of determining the impact of adoption.
	In June 2014, the FASB issued ASU 2014-11, which amends existing guidance in ASC 860, Transfers and Servicing. The amended guidance amends certain criteria when evaluating effective control in certain repurchase agreement transactions and eliminates specific guidance on repurchase financing and requires that these transactions be treated in the same manner as repurchase transactions. Additionally, the amended guidance requires additional disclosures for repurchase agreements. The Company will adopt the ASU for interim and annual periods beginning January 1, 2015. The Company is currently in the process of determining the impact of adoption.
	In August 2014, the FASB issued ASU 2014-14, which amends ASC 310, Receivables. The amended guidance requires creditors to classify certain foreclosed government guaranteed mortgage loans as a receivable from the guarantor that is measured at the amount expected to be recovered under the guarantee, without treating the guarantee as a separate unit of account. The Company will adopt the ASU for interim and annual periods beginning January 1, 2015. The Company is currently in the process of determining the impact of adoption.
	In November 2014, the FASB issued ASU 2014-17, which amends ASC 805, Business Combinations. The amended guidance gives an acquired entity the option to apply pushdown accounting in its stand-alone financial statements. The Company will adopt the ASU for interim and annual periods beginning January 1, 2015. The Company is currently in the process of determining the impact of adoption.

Certain_LongDuration_Contracts

Certain Long-Duration Contracts	12 Months Ended
	Dec. 31, 2014
Certain Long-Duration Contracts	-4	Certain Long-Duration Contracts
	Variable Annuity Contracts
	Contractholder assets are invested in general and separate account investment options as directed by the contractholder. The Company issues variable annuity contracts through its separate accounts. The Company also provides various forms of guarantees to benefit the related contractholders. The Company provides five primary guarantee types: (1) GMDB; (2) GLWB; (3) GMAB; (4) a hybrid guarantee with GMAB and GLWB; and (5) GMIB.
	The GMDB, offered on every variable annuity contract, provides a specified minimum return upon death. Many of these death benefits are spousal, whereby a death benefit will be paid upon death of the first spouse. The survivor has the option to terminate the contract or continue it by having the death benefit paid into the contract and having a second death benefit paid upon the survivor’s death.
	The GLWB, offered in the Company’s Lifetime Income products, are living benefits that provide for enhanced retirement income security without the liquidity loss associated with annuitization. The withdrawal rates vary based on the age when withdrawals begin and are applied to a benefit base to determine the guaranteed lifetime income amount available to a contractholder. The benefit base is equal to the variable annuity premium at contract issuance and may increase as a result of a feature driven by account performance and policy duration.
	The GMAB, which was offered in the Company’s Capital Preservation Plus product, is a living benefit that provides the contractholder with a guaranteed return of deposits, adjusted proportionately for withdrawals, after a specified time period (5, 7 or 10 years) selected by the contractholder at the issuance of the variable annuity contract. In some cases, the contractholder also has the option, after a specified time period, to drop the guarantee and continue the variable annuity contract without the GMAB. In general, the GMAB requires a minimum allocation to guaranteed term options or adherence to limitations required by an approved asset allocation strategy.
	The GMIB, which was offered with several variable annuity contracts, is a living benefit that provides the contractholder with a guaranteed annuitization stream of income.
	The following table summarizes information regarding variable annuity contracts with guarantees invested in general and separate accounts, as of the dates indicated (a contract may contain multiple guarantees):
			December 31, 2014									December 31, 2013
	(in millions)		General		Separate			Net		Average		General		Separate		Net		Average
			account		account			amount		age2		account		account		amount		age2
			value		value			at risk1				value		value		at risk1
	Contracts with GMDB:
	Return of net deposits		$	872	$	23,079		$	21		65	$	916	$	19,927	$	13		64
	Minimum return or anniversary contract value			1,918		33,662			292		69		2,031		33,520		237		69
	Total contracts with GMDB		$	2,790	$	56,741		$	313		68	$	2,947	$	53,447	$	250		67
	GLWB Minimum return or anniversary contract value		$	135	$	31,031		$	195		66	$	178	$	28,071	$	74		64
	GMAB Return of net deposits3		$	43	$	1,552		$	—		67	$	92	$	2,383	$	—		64
	GMIB Minimum return or anniversary contract value		$	45	$	451		$	1		66	$	49	$	510	$	—		64
	1	Net amount at risk is calculated on a policy-level basis and equals the respective guaranteed benefit less the account value (or zero if the account value exceeds the guaranteed benefit).
	2	Represents the weighted average attained age of contractholders.
	3	Contracts with the hybrid accumulation/withdrawal benefits are included with the accumulation benefits contracts.
	The following table summarizes the reserve balances for guarantees on variable annuity contracts, as of the dates indicated:
			December 31,
	(in millions)		2014		2013
	GMDB		$	76	$	55
	GLWB1		$	174	$	(1,075	)
	GMAB1, 2		$	3	$	(19	)
	GMIB		$	1	$	2
	1	The changes in reserve balances for withdrawal benefits and accumulation benefits were primarily driven by declines in key interest rates, partially offset by rising equity markets during 2014. Refer to Note 7 for discussion of the related derivative programs.
	2	Contracts with the hybrid accumulation/withdrawal benefits are included with the accumulation benefits contracts.
	Paid claims for GMDBs were $11 million and $22 million for the years ended December 31, 2014 and 2013, respectively.
	Paid claims for GLWBs, GMABs and GMIBs were immaterial for the years ended December 31, 2014 and 2013.
	The following table summarizes the account balances of deferred variable annuity contracts with guarantees invested in separate accounts, as of the dates indicated:
			December 31,
	(in millions)		2014		2013
	Mutual funds:
	Bond		$	5,280	$	5,685
	Domestic equity			47,316		43,505
	International equity			2,969		3,179
	Total mutual funds		$	55,565	$	52,369
	Money market funds			1,176		1,078
	Total1		$	56,741	$	53,447
	1	Excludes $31.3 billion and $30.6 billion as of December 31, 2014 and 2013, respectively, of separate account assets not related to deferred variable annuity contracts with guarantees, primarily attributable to retirement plan, variable universal life and COLI products.
	The Company did not transfer any assets from the general account to the separate account to cover guarantees for any of its variable annuity contracts during the years ended December 31, 2014 and 2013.
	Universal and Variable Universal Life Insurance Contracts
	The Company offers certain universal life and variable universal life insurance products with no-lapse guarantees. These no-lapse guarantees provide that a policy will not lapse so long as the policyholder makes minimum premium payments. The reserve balances on these guarantees were $401 million and $325 million as of December 31, 2014 and 2013, respectively. Paid claims on contracts maintained in force by these guarantees were immaterial for the years ended December 31, 2014 and 2013.
	The following table summarizes information regarding universal and variable universal life insurance contracts with no-lapse guarantees invested in general and separate accounts, as of the dates indicated:
	(in millions)		General account		Separate account			Adjusted insurance		Average age2
			value		value			in force1
	December 31, 2014		$	1,954	$	2,191		$	41,484		51
	December 31, 20133		$	1,522	$	2,235		$	36,956		51
	1	The adjusted insurance in force is calculated on a policy-level basis and equals the respective guaranteed death benefit less the account value.
	2	Represents the weighted average attained age of contractholders.
	3	Amounts above are based on all policies with no-lapse guarantees. Previously, only those policies with a no-lapse guarantee carrying a reserve were included in the disclosure.

Deferred_Policy_Acquisition_Co

Deferred Policy Acquisition Costs	12 Months Ended
	Dec. 31, 2014
Deferred Policy Acquisition Costs	-5	Deferred Policy Acquisition Costs
	The following table summarizes changes in the DAC balance, as of the dates indicated:
			December 31,
	(in millions)		2014			2013			2012
	Balance at beginning of year		$	3,778		$	3,249		$	3,487
	Capitalization of DAC			685			604			470
	Amortization of DAC, excluding unlocks			(397	)		(373	)		(525	)
	Amortization of DAC related to unlocks			190			(1	)		(50	)
	Adjustments to DAC related to unrealized gains and losses on available-for-sale securities			(193	)		299			(133	)
	Balance at end of year		$	4,063		$	3,778		$	3,249
	During 2014, the Company recognized a decrease in DAC amortization of $190 million as a result of the annual comprehensive review of model assumptions and enhancements. The updated assumptions were primarily related to the actual performance of the block of business since the prior year review and the expectations for lapses, partially offset by an update to the Company’s long-term assumptions for separate account investment performance.
	During 2013, the net change in DAC amortization as a result of the annual comprehensive review of model assumptions was immaterial.
	During 2012, the Company incurred additional DAC amortization of $50 million as a result of the annual comprehensive review of model assumptions, as well as a deviation from equity market performance as compared to assumed net separate account returns. The updated assumptions were primarily related to actual gross profits and the in force block of business deviating from expectations, renewal premiums, general account margins and lapses.

Investments

Investments	12 Months Ended
	Dec. 31, 2014
Investments	-6	Investments
	Available-for-Sale Securities
	The following table summarizes the amortized cost, unrealized gains and losses and fair value of available-for-sale securities, as of the dates indicated:
	(in millions)		Amortized			Unrealized			Unrealized			Fair value
			cost			gains			losses
	December 31, 2014
	Fixed maturity securities:
	U.S. government and agencies		$	448		$	79		$	—		$	527
	Obligations of states, political subdivisions and foreign governments			1,966			320			1			2,285
	Corporate public securities			19,851			1,519			120			21,250
	Corporate private securities			4,398			286			34			4,650
	Residential mortgage-backed securities			3,694			190			45			3,839
	Commercial mortgage-backed securities			1,431			74			3			1,502
	Other asset-backed securities			1,410			27			72			1,365
	Total fixed maturity securities		$	33,198		$	2,495		$	275		$	35,418
	Equity securities			6			15			—			21
	Total available-for-sale securities		$	33,204		$	2,510		$	275		$	35,439
	December 31, 2013
	Fixed maturity securities:
	U.S. government and agencies		$	484		$	79		$	2		$	561
	Obligations of states, political subdivisions and foreign governments			1,892			111			40			1,963
	Corporate public securities			18,004			1,076			295			18,785
	Corporate private securities			4,374			258			38			4,594
	Residential mortgage-backed securities			3,919			163			79			4,003
	Commercial mortgage-backed securities			1,439			86			21			1,504
	Other asset-backed securities			890			26			77			839
	Total fixed maturity securities		$	31,002		$	1,799		$	552		$	32,249
	Equity securities			6			18			—			24
	Total available-for-sale securities		$	31,008		$	1,817		$	552		$	32,273
	The fair value of the Company’s investments may fluctuate significantly in response to changes in interest rates, investment quality ratings and credit spreads. The Company has the ability and intent to hold equity securities until recovery. The Company does not have the intent to sell, nor is it more likely than not it will be required to sell, debt securities in an unrealized loss position.
	The following table summarizes the amortized cost and fair value of fixed maturity securities, by contractual maturity, as of December 31, 2014. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without early redemption penalties.
	(in millions)		Amortized			Fair
			cost			value
	Fixed maturity securities:
	Due in one year or less		$	1,018		$	1,037
	Due after one year through five years			9,196			9,898
	Due after five years through ten years			8,267			8,617
	Due after ten years			8,182			9,160
	Subtotal		$	26,663		$	28,712
	Residential mortgage-backed securities			3,694			3,839
	Commercial mortgage-backed securities			1,431			1,502
	Other asset-backed securities			1,410			1,365
	Total fixed maturity securities		$	33,198		$	35,418
	The following table summarizes components of net unrealized gains and losses, as of the dates indicated:
			December 31,
	(in millions)		2014			2013
	Net unrealized gains on available-for-sale securities, before adjustments, taxes and fair value hedging		$	2,235		$	1,265
	Net unrealized gains on available-for-sale securities, before adjustments and taxes1		$	2,235		$	1,265
	Adjustment to DAC and other expense			(372	)		(176	)
	Adjustment to future policy benefits and claims			(159	)		(89	)
	Adjustment to policyholder dividend obligation			(120	)		(85	)
	Deferred federal income tax expense			(548	)		(314	)
	Net unrealized gains on available-for-sale securities		$	1,036		$	601
	1	Includes net unrealized losses of $9 million and $40 million as of December 31, 2014 and 2013, respectively, related to the non-credit portion of other-than-temporarily impaired securities.
	The following table summarizes the change in net unrealized gains and losses reported in accumulated other comprehensive income, for the years ended:
			December 31,
	(in millions)		2014			2013
	Balance at beginning of year		$	601		$	1,264
	Unrealized gains and losses arising during the year:
	Net unrealized gains (losses) on available-for-sale securities before adjustments			939			(1,657	)
	Non-credit impairments and subsequent changes in fair value of impaired debt securities			31			8
	Net adjustment to DAC and other expense			(196	)		306
	Net adjustment to future policy benefits and claims			(70	)		206
	Net adjustment to policyholder dividend obligations			(35	)		92
Related federal income tax (expense) benefit			(234	)		366
Unrealized gains (losses) on available-for-sale securities		$	435		$	(679	)
Reclassification adjustment for net losses realized on available-for-sale securities, net of tax benefit ($0 and $8 as of December 31, 2014 and 2013, respectively)			—			(16	)
Net unrealized gains (losses) on available-for-sale securities		$	435		$	(663	)
Balance at end of year		$	1,036		$	601
The following table summarizes, by asset class, available-for-sale securities, in an unrealized loss position based on the amount of time each type of security has been in an unrealized loss position, as well as the related fair value, as of the dates indicated:
		Less than or equal to one year						More than one year					Total
(in millions)		Fair			Unrealized			Fair			Unrealized		Unrealized
		value			losses			value			losses		losses1
December 31, 2014
Fixed maturity securities:
Corporate public securities		$	1,642		$	63		$	1,578		$	57	$	120
Residential mortgage-backed securities			268			2			487			43		45
Other asset-backed securities			662			5			493			67		72
Other			589			27			457			11		38
Total2		$	3,161		$	97		$	3,015		$	178	$	275
December 31, 2013
Fixed maturity securities:
Corporate public securities		$	4,889		$	256		$	442		$	39	$	295
Residential mortgage-backed securities			725			16			604			63		79
Other asset-backed securities			507			6			144			71		77
Other			1,838			85			222			16		101
Total2		$	7,959		$	363		$	1,412		$	189	$	552
1	As of December 31, 2014 and 2013, there were $66 million and $82 million, respectively, of unrealized losses related to available-for-sale securities with a fair value to amortized cost ratio of less than 80%.
2	Represents 541 and 816 available-for-sale securities in an unrealized loss position as of December 31, 2014 and 2013, respectively.
Residential mortgage-backed securities are assessed for impairment using default estimates based on loan level data, where available. Where loan level data is not available, a proxy based on collateral characteristics is used. The impairment assessment considers loss severity as a function of multiple factors, including unpaid balance, interest rate, mortgage insurance ratios, assessed property value at origination, change in property value, loan-to-value (“LTV”) ratio at origination and prepayment speeds. Cash flows generated by the collateral are then utilized, along with consideration for the instrument’s position in the overall structure, to determine cash flows associated with the security.
Certain other asset-backed securities are assessed for impairment using expected cash flows based on various inputs, including default estimates based on the underlying corporate securities, historical and forecasted loss severities or other market inputs when recovery estimates are not feasible. When the collateral is regional bank and insurance company trust preferred securities, default estimates used to estimate cash flows are based on U.S. Bank Rating service data and broker research.
The Company believes the unrealized losses on these available-for-sale securities represent temporary fluctuations in economic factors that are not indicative of other-than-temporary impairment.
Mortgage Loans, Net of Allowance
The following table summarizes the amortized cost of mortgage loans by method of evaluation for credit loss, and the related valuation allowances by type of credit loss, as of the dates indicated:
		December 31,
(in millions)		2014			2013
Amortized cost:
Loans with non-specific reserves		$	7,279		$	6,350
Loans with specific reserves			17			26
Total amortized cost		$	7,296		$	6,376
Valuation allowance:
Non-specific reserves		$	21		$	29
Specific reserves			5			6
Total valuation allowance		$	26		$	35
Mortgage loans, net of allowance		$	7,270		$	6,341
The following table summarizes activity in the valuation allowance for mortgage loans, for the years ended:
		December 31,
(in millions)		2014			2013			2012
Balance at beginning of year		$	35		$	44		$	60
Current period provision1			(8	)		(4	)		2
Recoveries2			(1	)		(5	)		(15	)
Charge offs and other			—			—			(3	)
Balance at end of year		$	26		$	35		$	44
1	Includes specific reserve provisions and all changes in non-specific reserves.
2	Includes recoveries on sales and increases in the valuation of loans with specific reserves.
As of December 31, 2014 and 2013, the carrying values of commercial mortgage loans specifically reserved were $12 million and $20 million, respectively, which is net of $5 million and $6 million, respectively, in specific reserves.
Interest income recognized on impaired commercial mortgage loans was $1 million and $3 million for the years ended December 31, 2014 and 2013, respectively. The average recorded investment was $16 million and $30 million for the years ended December 31, 2014 and 2013, respectively.
As of December 31, 2014 and 2013, the Company’s mortgage loans classified as delinquent and/or in non-accrual status were immaterial in relation to the total mortgage loan portfolio. The Company had no mortgage loans 90 days or more past due and still accruing interest.
Management evaluates the credit quality of individual mortgage loans and the portfolio as a whole through a number of loan quality measurements, including, but not limited to, LTV and debt service coverage (“DSC”) ratios. The LTV ratio is calculated as a ratio of the amortized cost of a loan to the estimated value of the underlying collateral. DSC is the amount of cash flow generated by the underlying collateral of the mortgage loan available to meet periodic interest and principal payments of the loan. This process identifies mortgage loans representing the lowest risk profile and lowest potential for loss and those representing the highest risk profile and highest potential for loss. These factors are updated and evaluated at least annually.
The following table summarizes the LTV ratio and DSC ratios of the mortgage loan portfolio, as of the dates indicated:
		LTV ratio											DSC ratio
(in millions)		Less			80% -			90% or			Total		Greater		1.00-		Less		Total
		than			less			greater					than		1.1		than
		80%			than								1.1				1
					90%
31-Dec-14
Apartment		$	2,156		$	111		$	17		$	2,284	$	2,252	$	26	$	6	$	2,284
Industrial			1,131			34			35			1,200		1,048		89		63		1,200
Office			1,004			16			20			1,040		990		4		46		1,040
Retail			2,506			64			11			2,581		2,421		128		32		2,581
Other			191			—			—			191		191		—		—		191
Total1		$	6,988		$	225		$	83		$	7,296	$	6,902	$	247	$	147	$	7,296
31-Dec-13
Apartment		$	1,788		$	52		$	30		$	1,870	$	1,857	$	6	$	7	$	1,870
Industrial			951			52			86			1,089		893		122		74		1,089
Office			837			30			38			905		800		43		62		905
Retail			2,236			41			21			2,298		2,214		61		23		2,298
Other			213			—			1			214		214		—		—		214
Total2		$	6,025		$	175		$	176		$	6,376	$	5,978	$	232	$	166	$	6,376
1	As of December 31, 2014, the weighted average DSC ratios for the respective LTV ratio ranges above were 1.97, 1.27 and 0.90, with a total weighted average DSC ratio of 1.93. As of December 31, 2014, the weighted average LTV ratios for the respective DSC ratio ranges above were 60%, 59% and 90%, with a total weighted average LTV ratio of 60%.
2	As of December 31, 2013, the weighted average DSC ratios for the respective LTV ratio ranges above were 1.77, 1.22 and 1.00, with a total weighted average DSC ratio of 1.74. As of December 31, 2013, the weighted average LTV ratios for the respective DSC ratio ranges above were 60%, 61% and 91%, with a total weighted average LTV ratio of 61%.
While these loan quality measurements contribute to management’s assessment of relative credit risk in the mortgage loan portfolio for the dates indicated, based on underwriting criteria and ongoing assessment of the properties’ performance, management believes the amounts, net of valuation allowance, are collectible.
Available-For-Sale Securities on Deposit, Held in Trust and Pledged as Collateral
Available-for-sale securities with a carrying value of $8 million were on deposit with various regulatory agencies as required by law as of December 31, 2014 and 2013. Additionally, available-for-sale securities with a carrying value of $683 million and $849 million were pledged as collateral to secure recoveries under reinsurance contracts and other funding agreements as of December 31, 2014 and 2013, respectively. These securities are primarily included in fixed maturity securities in the consolidated balance sheets.
Tax Credit Funds
The Company has sold $1.3 billion and $1.2 billion in Tax Credit Funds to unrelated third parties as of December 31, 2014 and 2013, respectively. The Company has guaranteed after-tax benefits to the third party investors through periods ending in 2029. The Company held immaterial reserves on these transactions as of December 31, 2014 and 2013. These guarantees are in effect for periods of approximately 15 years each. The Tax Credit Funds provide a stream of tax benefits to the investors that will generate a yield and return of capital. If the tax benefits are not sufficient to provide these cumulative after-tax yields, the Company must fund any shortfall. The maximum amount of undiscounted future payments that the Company could be required to pay the investors under the terms of the guarantees is $744 million, but the Company does not anticipate making any material payments related to the guarantees. The Company’s risks are mitigated in the following ways: (1) the Company has the right to buyout the equity related to the guarantee under certain circumstances, (2) the Company may replace underperforming properties to mitigate exposure to guarantee payments and (3) the Company oversees the asset management of the deals.
Consolidated VIEs
The Company has relationships with VIEs where the Company is the primary beneficiary. These consolidated VIEs are primarily made up of Tax Credit Funds with guarantees to limited partners. Net assets (controlling and noncontrolling interests) of all consolidated VIEs totaled $640 million and $680 million as of December 31, 2014 and 2013, respectively, and are included within the balance sheet primarily as other investments of $580 million, other assets of $109 million and other liabilities of $75 million as of December 31, 2014, other investments of $554 million, other assets of $182 million and other liabilities of $82 million as of December 31, 2013. The Company’s general credit is not exposed to the creditors or beneficial interest holders of these consolidated VIEs.
Unconsolidated VIEs
In addition to the consolidated VIEs, the Company holds investments in VIEs where the Company is not the primary beneficiary, which are primarily investments in Tax Credit Funds without guarantees to limited partners. The carrying value of these investments was $113 million and $104 million as of December 31, 2014 and 2013, respectively. In addition, the Company has made commitments for further investments in these VIEs of $17 million and $29 million as of December 31, 2014 and 2013, respectively.
Net Investment Income
The following table summarizes net investment income, by investment type, for the years ended:
		December 31,
(in millions)		2014			2013			2012
Fixed maturity securities, available-for-sale		$	1,575		$	1,565		$	1,506
Mortgage loans			362			348			366
Policy loans			51			52			53
Other			(29	)		(57	)		(45	)
Gross investment income		$	1,959		$	1,908		$	1,880
Investment expenses			59			59			55
Net investment income		$	1,900		$	1,849		$	1,825
Net Realized Investment Gains and Losses, Including Other-Than-Temporary Impairments
The following table summarizes net realized investment gains and losses, including other-than-temporary impairments, by source, for the years ended:
		December 31,
(in millions)		2014			2013			2012
Net realized derivative (losses) gains		$	(1,087	)	$	705		$	314
Realized gains on sales			31			32			48
Realized losses on sales			(19	)		(54	)		(23	)
Other			2			—			12
Net realized investment (losses) gains before other-than-temporary impairments on fixed maturity securities		$	(1,073	)	$	683		$	351
Other-than-temporary impairments on fixed maturity securities1			(5	)		(5	)		(32	)
Net realized investment (losses) gains, including other-than-temporary impairments		$	(1,078	)	$	678		$	319
1	Other-than-temporary impairments on fixed maturity securities are net $1 million, $6 million and $36 million of non-credit losses included in other comprehensive income for the years ended December 31, 2014, 2013 and 2012, respectively.
Proceeds from the sale of available-for-sale securities were $0.6 billion, $1.1 billion and $0.8 billion during the years ended December 31, 2014, 2013 and 2012, respectively. Gross gains of $17 million, $31 million and $47 million and gross losses of $10 million, $50 million and $20 million were realized on sales of available-for-sale securities during the years ended December 31, 2014, 2013 and 2012, respectively.
The following table summarizes the cumulative credit losses, for the years ended:
		December 31,
(in millions)		2014			2013			2012
Cumulative credit losses at beginning of year1		$	(272	)	$	(289	)	$	(328	)
New credit losses			(2	)		(3	)		(18	)
Incremental credit losses			(4	)		(3	)		(10	)
Losses related to securities included in the beginning balance sold or paid down during the period			24			23			67
Cumulative credit losses at end of year1		$	(254	)	$	(272	)	$	(289	)
1	Cumulative credit losses are defined as amounts related to the Company’s credit portion of the other-than-temporary impairment losses on debt securities that the Company does not intend to sell and that it is not more likely than not the Company will be required to sell prior to recovery of the amortized cost basis.

Derivative_Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2014
Derivative Instruments	-7	Derivative Instruments
	The Company is exposed to certain risks related to its ongoing business operations which are managed using derivative instruments.
	Interest rate risk management. The Company uses interest rate contracts, primarily interest rate swaps, to reduce or alter interest rate exposure arising from mismatches between assets and liabilities. In the case of interest rate swaps, the Company enters into a contractual agreement with a counterparty to exchange, at specified intervals, the difference between fixed and variable rates of interest, calculated on a reference notional amount.
	Interest rate swaps are used by the Company in association with fixed and variable rate investments to achieve cash flow streams that support certain financial obligations of the Company and to produce desired investment returns. As such, interest rate swaps are generally used to convert fixed rate cash flow streams to variable rate cash flow streams or vice versa. The Company also enters into interest rate swap transactions, which are structured to provide an offset against the negative impact of higher interest rates on the Company’s capital position.
	Equity market and interest rate risk management. The Company has a variety of variable annuity products with guaranteed benefit features. These products and related obligations expose the Company to various market risks, primarily equity and interest rate risks. Adverse changes in the equity markets or interest rate movements expose the Company to significant volatility. To mitigate these risks and hedge the guaranteed benefit obligations, the Company enters into a variety of derivatives including interest rate swaps, equity index futures, options and total return swaps.
	Other risk management. As part of its regular investing activities, the Company may purchase foreign currency denominated investments. These investments and the associated income expose the Company to volatility associated with movements in foreign exchange rates. As foreign exchange rates change, the increase or decrease in the cash flows of the derivative instrument generally offsets the changes in the functional-currency equivalent cash flows of the hedged item. To mitigate this risk, the Company uses cross-currency swaps and futures, which are primarily included in other derivative contracts in the following tables.
	Credit risk associated with derivatives transactions. The Company periodically evaluates the risks within the derivative portfolios due to credit exposure When evaluating this risk, the Company considers several factors which include, but are not limited to, the counterparty credit risk associated with derivative receivables, the Company’s own credit as it relates to derivative payables, the collateral thresholds associated with each counterparty and changes in relevant market data in order to gain insight into the probability of default by the counterparty. In addition, the impact the Company’s exposure to credit risk could have on the effectiveness of the Company’s hedging relationships is considered. As of December 31, 2014 and 2013, the impact of the exposure to credit risk on the fair value measurement of derivatives and the effectiveness of the Company’s hedging relationships was immaterial.
	The following table summarizes the fair value and related notional amounts of derivative instruments, as of the dates indicated:
			Derivative assets						Derivative liabilities
	(in millions)		Fair value			Notional			Fair value			Notional
	December 31, 2014
	Derivatives designated and qualifying as hedging instruments		$	29		$	381		$	9		$	176
	Derivatives not designated as hedging instruments:
	Interest rate contracts		$	2,602		$	32,829		$	2,611		$	32,756
	Equity contracts			411			5,990			—			—
	Total return swaps			—			—			41			2,808
	Other derivative contracts			—			—			3			2
	Total derivative instruments1		$	3,042		$	39,200		$	2,664		$	35,742
	Accrued interest on derivative assets and liabilities			243						244
	Total derivative positions		$	3,285					$	2,908
	December 31, 2013
	Derivatives designated and qualifying as hedging instruments		$	1		$	6		$	26		$	345
	Derivatives not designated as hedging instruments:
	Interest rate contracts		$	1,787		$	26,156		$	2,100		$	29,715
	Equity contracts			343			6,556			—			—
	Total return swaps			6			1,101			52			1,183
	Other derivative contracts			—			—			5			2
	Total derivative instruments1		$	2,137		$	33,819		$	2,183		$	31,245
	Accrued interest on derivative assets and liabilities			196						227
	Total derivative positions		$	2,333					$	2,410
	1	Derivative assets and liabilities are included in other assets and other liabilities, respectively, in the consolidated balance sheets.
	Of the $3.3 billion and $2.3 billion of fair value of total derivative assets at December 31, 2014 and 2013, $2.6 billion and $1.7 billion, respectively, are subject to master netting agreements. The Company received $535 million and $382 million of cash collateral and held $64 million and $29 million, respectively, of securities as off-balance sheet collateral, resulting in an immaterial uncollateralized position as of December 31, 2014 and 2013. Of the $2.9 billion and $2.4 billion of fair value of total derivative liabilities at December 31, 2014 and 2013, $2.6 billion and $1.7 billion, respectively, are subject to master netting agreements. The Company posted $330 million and $435 million of cash collateral and pledged securities with a fair value of $174 million and $173 million, respectively, resulting in an immaterial uncollateralized position as of December 31, 2014 and 2013.
	The following table summarizes gains and losses for derivative instruments recognized in net realized investment gains and losses in the consolidated statements of operations, for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Derivatives designated and qualifying as hedging instruments		$	—		$	(1	)	$	(1	)
	Derivatives not designated as hedging instruments:
	Interest rate contracts		$	142		$	(209	)	$	(125	)
	Equity contracts			(79	)		(776	)		(665	)
	Total return swaps			(195	)		(321	)		(343	)
	Other derivative contracts			4			(9	)		(1	)
	Net interest settlements			20			14			53
	Total derivative losses1		$	(108	)	$	(1,302	)	$	(1,082	)
	Change in embedded derivatives on guaranteed benefit annuity programs2			(1,271	)		1,751			1,185
	Other revenue on guaranteed benefit annuity programs			292			256			211
	Change in embedded derivative liabilities and related fees		$	(979	)	$	2,007		$	1,396
	Net realized derivative (losses) gains		$	(1,087	)	$	705		$	314
	1	Included in total derivative losses are economic hedging gains (losses) of $941 million, $(1.8) billion and $(827) million related to the guaranteed benefit annuity programs for the years ended December 31, 2014, 2013 and 2012, respectively. Also included are economic hedging (losses) gains of $(1.0) billion, $645 million and $(129) million, respectively, related to the program that protects against the negative impact of higher interest rates on the Company’s statutory surplus position.
	2	For the individual variable annuity business, the annual comprehensive review of model assumptions included a favorable impact for the years ended December 31, 2014 and 2013, primarily due to model enhancements and updated assumptions for discounting and benefit utilization, partially offset by mortality and lapse rates.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Measurements	-8	Fair Value Measurements
	The following table summarizes assets and liabilities held at fair value on a recurring basis as of December 31, 2014:
	(in millions)		Level 1			Level 2			Level 3			Total
	Assets
	Investments:
	Fixed maturity securities, available-for-sale:
	U.S. government and agencies		$	523		$	1		$	3		$	527
	Obligations of states, political subdivisions and foreign governments			66			2,219			—			2,285
	Corporate public securities			—			21,158			92			21,250
	Corporate private securities			—			3,659			991			4,650
	Residential mortgage-backed securities			1,034			2,796			9			3,839
	Commercial mortgage-backed securities			—			1,499			3			1,502
	Other asset-backed securities			—			1,196			169			1,365
	Total fixed maturity securities, available-for-sale, at fair value		$	1,623		$	32,528		$	1,267		$	35,418
	Other investments at fair value1			42			899			36			977
	Investments at fair value		$	1,665		$	33,427		$	1,303		$	36,395
	Derivative instruments - assets			—			2,631			411			3,042
	Separate account assets			84,583			1,387			2,106			88,076
	Assets at fair value		$	86,248		$	37,445		$	3,820		$	127,513
	Liabilities
	Future policy benefits and claims:
	Embedded derivatives on living benefits		$	—		$	—		$	(177	)	$	(177	)
	Embedded derivatives on indexed products			—			—			(84	)		(84	)
	Total future policy benefits and claims		$	—		$	—		$	(261	)	$	(261	)
	Derivative instruments - liabilities			—			(2,661	)		(3	)		(2,664	)
	Liabilities at fair value		$	—		$	(2,661	)	$	(264	)	$	(2,925	)
	1	Other investments at fair value includes $21 million of trading securities as of December 31, 2014.
	The following table presents the rollforward of Level 3 assets and liabilities held at fair value on a recurring basis during the year ended December 31, 2014:
	(in millions)		Fixed			Other			Derivative			Separate			Total assets			Liabilities at
			maturity			investments			assets3			account			at fair value			fair value3
			securities2									assets
	Balance as of December 31, 2013		$	1,088		$	45		$	343		$	2,083		$	3,559		$	1,005
	Net gains (losses)
	In operations1			(5	)		6			40			23			64			(1,269	)
	In other comprehensive income			21			1			—			—			22			—
	Purchases			121			—			46			—			167			—
	Sales			(241	)		(16	)		(18	)		—			(275	)		—
	Transfers into Level 3			400			—			—			—			400			—
	Transfers out of Level 3			(117	)		—			—			—			(117	)		—
	Balance as of December 31, 2014		$	1,267		$	36		$	411		$	2,106		$	3,820		$	(264	)
	1	Net gains and losses included in operations are reported in net realized investment gains and losses and interest credited to policyholder accounts. The net unrealized gains on separate account assets are attributable to contractholders and therefore are not included in the Company’s earnings. The change in unrealized (losses) gains included in operations on assets and liabilities still held at the end of the year was $(1.3) billion for future policy benefits and claims, $154 million for derivative assets, and $6 million for other investments at fair value.
	2	Non-binding broker quotes were utilized to determine a fair value of $1.1 billion of total fixed maturity securities as of December 31, 2014.
	3	Non-binding broker quotes were utilized to determine a fair value of all Level 3 derivative assets and liabilities.
	Transfers into and out of Level 3 during the year ended December 31, 2014 are primarily due to certain corporate private securities, which changed pricing sources between broker quotes and independent pricing services. There were no material transfers between Levels 1 and 2 during the year ended December 31, 2014.
	As discussed in Note 2, the valuation of embedded derivatives in living benefit guarantees and equity indexed products incorporates many inputs. Significant unobservable inputs for living benefit guarantees include discounting, index volatility, mortality, lapse rates, wait period and benefit utilization, while significant unobservable inputs for equity indexed products include mortality, lapse rates and index volatility. For both products, the Company derives these inputs, which vary widely by product, attained age, policy duration, benefits in the money (living benefit guarantees only) and the existence of surrender charges, from current experience and industry data. The fair value for these benefits is calculated using the mean of discounted cash flows across numerous random scenarios, an approach that is commonly used by the insurance industry for this type of valuation. This process considers a broader range of assumptions than what would be found in a deterministic approach.
	Living Benefit Guarantees
	The following table summarizes significant unobservable inputs used for fair value measurements for living benefits liabilities classified as Level 3 as of December 31, 2014:
	Unobservable Inputs		Range
	Mortality		0.1% - 8%2
	Lapse		0% - 35%
	Wait period		0 yrs – 30 yrs3
	Efficiency of benefit utilization1		65% -100%
	Discount rate		See footnote 4
	Index volatility		15% - 25%
	1	The unobservable input is not applicable to GMABs.
	2	Represents the mortality for the majority of business with living benefits, with policyholders ranging from 45 to 85.
	3	A portion of the contractholders could never use the benefit, which would extend the range to an indeterminate period.
	4	Incorporates the liquidity and non-performance risk adjustment. The liquidity spread takes into consideration market observables for spreads in illiquid assets. The non-performance risk adjustment reflects an additional spread over LIBOR determined by market observables for similarly rated public bonds.
	The following changes in any of the significant unobservable inputs presented in the table above may result in a change in the fair value measurements of the living benefits liability:
	Higher mortality rates tend to decrease the value of the liability and lower mortality rates tend to increase the value of the liability.
	Higher lapse rates tend to decrease the value of the liability and lower lapse rates tend to increase the value of the liability. Factors that impact the predicted lapse rate can include: age, policy duration, policy size, benefit in-the-moneyness, tax status (i.e. qualified or non-qualified), interest rate levels and applicable surrender charges. All else being equal, policies that are in-the-money will have lower lapse rates than policies that are out-of-the-money, and policies that have a surrender charge present will have lower lapse rates than policies without a surrender charge.
	The assumed wait period and the efficiency of utilization determine the timing and amount of living benefits withdrawals. These assumptions vary by the product type, age of the policyholder and policy duration. Many products have a bonus feature which enhances the guarantee on every policy anniversary for the first ten years so long as withdrawals have not commenced. All else being equal, policies commencing withdrawals at a time around the year ten bonus will have higher liability values than policies commencing withdrawals 20 years after issue or policies commencing withdrawals only one year after issue. In addition, policies that are assumed to withdraw the maximum permitted amount will have a higher liability value than a policy that is assumed to withdraw less than the maximum allowed amount.
	A higher discount rate tends to decrease the value of the liability and a lower discount rate tends to increase the value of the liability.
	Higher index volatility tends to increase the value of the liability and lower index volatility tends to decrease the value of the liability.
Equity Indexed Products
The following table summarizes significant unobservable inputs used for fair value measurements for indexed universal life equity indexed products classified as Level 3 as of December 31, 2014:
Unobservable Inputs		Range
Mortality		0% - 4%1
Lapse		0% - 10%
Index volatility		15% - 25%
1	Represents the mortality for the majority of business, with policyholders ranging from 0 to 75.
The following changes in any of the significant unobservable inputs presented in the table above may result in a change in the fair value measurements of the equity indexed products:
Higher mortality rates tend to decrease the value of the liability and lower mortality rates tend to increase the value of the liability.
Higher lapse rates tend to decrease the value of the liability and lower lapse rates tend to increase the value of the liability. Factors that impact the predicted lapse rate can include: age, policy duration, policy size, and applicable surrender charges. All else being equal, policies with a surrender charge present will have lower lapse rates than policies without a surrender charge.
Higher index volatility tends to increase the value of the liability and lower index volatility tends to decrease the value of the liability.
Separate Accounts
The Company’s separate account assets include an investment in a mutual fund with a non-readily determinable fair value. Net asset value has been used to estimate the fair value of this investment as a practical expedient. The investments are included in Level 3 as they may not be redeemed until the guarantee period expires in 2016. The investment strategy of this fund is to build a portfolio where the assets shall be sufficient to achieve a target portfolio value by the end of the guarantee period. The net asset value of this fund reported in separate account assets was $1.7 billion as of December 31, 2014 and 2013.
The following table summarizes assets and liabilities held at fair value on a recurring basis as of December 31, 2013:
(in millions)		Level 1			Level 2			Level 3			Total
Assets
Investments:
Fixed maturity securities, available-for-sale:
U.S. government and agencies		$	557		$	1		$	3		$	561
Obligations of states, political subdivisions and foreign governments			63			1,900			—			1,963
Corporate public securities			1			18,705			79			18,785
Corporate private securities			—			3,791			803			4,594
Residential mortgage-backed securities			791			3,203			9			4,003
Commercial mortgage-backed securities			—			1,504			—			1,504
Other asset-backed securities			—			645			194			839
Total fixed maturity securities, available-for-sale, at fair value		$	1,412		$	29,749		$	1,088		$	32,249
Other investments at fair value1			64			357			45			466
Investments at fair value		$	1,476		$	30,106		$	1,133		$	32,715
Derivative instruments - assets			—			1,794			343			2,137
Separate account assets			80,647			1,339			2,083			84,069
Assets at fair value		$	82,123		$	33,239		$	3,559		$	118,921
Liabilities
Future policy benefits and claims:
Embedded derivatives on living benefits		$	—		$	—		$	1,094		$	1,094
Embedded derivatives on indexed products			—			—			(84	)		(84	)
Total future policy benefits and claims		$	—		$	—		$	1,010		$	1,010
Derivative instruments - liabilities			—			(2,178	)		(5	)		(2,183	)
Liabilities at fair value		$	—		$	(2,178	)	$	1,005		$	(1,173	)
1	Other investments at fair value includes $31 million of trading securities as of December 31, 2013.
The following table presents the rollforward of Level 3 assets and liabilities held at fair value on a recurring basis during the year ended December 31, 2013:
(in millions)		Fixed			Other			Derivative			Separate			Total assets			Liabilities at
		maturity			investments			assets3			account			at fair value			fair value3
		securities2									assets
Balance as of December 31, 2012		$	1,197		$	62		$	822		$	2,025		$	4,106		$	(753	)
Net gains (losses)
In operations1			(1	)		(6	)		(447	)		58			(396	)		1,758
In other comprehensive income			1			6			—			—			7			—
Purchases			115			5			129			—			249			—
Sales			(232	)		(22	)		(161	)		—			(415	)		—
Transfers into Level 3			142			—			—			—			142			—
Transfers out of Level 3			(134	)		—			—			—			(134	)		—
Balance as of December 31, 2013		$	1,088		$	45		$	343		$	2,083		$	3,559		$	1,005
1	Net gains and losses included in operations are reported in net realized investment gains and losses and interest credited to policyholder accounts. The net unrealized gains on separate account assets are attributable to contractholders and therefore are not included in the Company’s earnings. The change in unrealized gains (losses) included in operations on assets and liabilities still held as of the end of the year was $1.8 billion for future policy benefits and claims, $(297) million for derivative assets and $(6) million for other investments at fair value.
2	Non-binding broker quotes were utilized to determine a fair value of $924 million of total fixed maturity securities as of December 31, 2013.
3	Non-binding broker quotes were utilized to determine a fair value of all Level 3 derivative assets and liabilities.
Transfers into and out of Level 3 during the year ended December 31, 2013 are primarily due to certain corporate private securities and other asset-backed securities, which changed pricing sources between broker quotes and independent pricing services. There were no transfers between Levels 1 and 2 during the year ended December 31, 2013.
Financial Instruments Not Carried at Fair Value
The following table summarizes the carrying value and fair value of the Company’s financial instruments not carried at fair value as of the dates indicated. The valuation techniques used to estimate these fair values are described below.
		December 31, 2014												December 31, 2013
(in millions)		Carrying			Fair			Level 2			Level 3			Carrying			Fair			Level 2		Level 3
		value			value									value			value
Assets
Investments:
Mortgage loans, net of allowance		$	7,270		$	7,616		$	—		$	7,616		$	6,341		$	6,481		$	—	$	6,481
Policy loans		$	992		$	992		$	—		$	992		$	987		$	987		$	—	$	987
Other investments		$	60		$	60		$	—		$	60		$	43		$	43		$	—	$	43
Liabilities
Investment contracts		$	23,470		$	21,742		$	—		$	21,742		$	21,874		$	20,436		$	—	$	20,436
Short-term debt		$	660		$	660		$	—		$	660		$	278		$	278		$	—	$	278
Long-term debt		$	709		$	1,069		$	1,060		$	9		$	707		$	1,004		$	997	$	7
Mortgage loans, net of allowance. The fair values of mortgage loans are estimated using discounted cash flow analyses based on interest rates currently being offered for similar loans to borrowers with similar credit ratings.
Policy loans. The carrying amount reported in the consolidated balance sheets approximates fair value.
Other investments. Other investments not held at fair value consist of FHLB stock. The carrying amount reported in the consolidated balance sheets approximates fair value.
Investment contracts. For investment contracts without defined maturities, fair value is the amount payable on demand, net of surrender charges. For investment contracts with known or determined maturities, fair value is estimated using discounted cash flow analysis. Interest rates used in this analysis are similar to currently offered contracts with maturities consistent with those remaining for the contracts being valued. The fair value of adjustable rate contracts approximates their carrying value.
Short-term debt. The carrying amount reported in the consolidated balance sheets approximates fair value.
Long-term debt. The fair values for long-term debt are based on estimated market prices using observable inputs from similar debt instruments.

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2014
Goodwill	-9	Goodwill
	The following table summarizes changes in the carrying value of goodwill by segment for the years indicated:
	(in millions)		Retirement		Individual		Total
			Plans		Products &
					Solutions - Life
					and NBSG
	Balance as of December 31, 20121		$	25	$	175	$	200
	Adjustments			—		—		—
	Balance as of December 31, 20131		$	25	$	175	$	200
	Adjustments			—		—		—
	Balance as of December 31, 20141		$	25	$	175	$	200
	1	The goodwill balances have not been previously impaired.

Closed_Block

Closed Block	12 Months Ended
	Dec. 31, 2014
Closed Block	-10	Closed Block
	The amounts shown in the following tables for assets, liabilities, revenues and expenses of the closed block are those that enter into the determination of amounts that are to be paid to policyholders.
	The following table summarizes financial information for the closed block, as of the dates indicated:
			December 31,
	(in millions)		2014			2013
	Liabilities:
	Future policyholder benefits		$	1,669		$	1,703
	Policyholder funds and accumulated dividends			139			141
	Policyholder dividends payable			22			23
	Policyholder dividend obligation			152			113
	Other policy obligations and liabilities			33			29
	Total liabilities		$	2,015		$	2,009
	Assets:
	Fixed maturity securities, available-for-sale		$	1,336		$	1,320
	Mortgage loans, net of allowance			272			257
	Policy loans			149			157
	Other assets			86			93
	Total assets		$	1,843		$	1,827
	Excess of reported liabilities over assets			172			182
	Portion of above representing other comprehensive income:
	Increase (decrease) in unrealized gain on fixed maturity securities, available-for-sale		$	35		$	(92	)
	Adjustment to policyholder dividend obligation			(35	)		92
	Total		$	—		$	—
	Maximum future earnings to be recognized from assets and liabilities		$	172		$	182
	Other comprehensive income:
	Fixed maturity securities, available-for-sale:
	Fair value		$	1,336		$	1,320
	Amortized cost			1,216			1,235
	Shadow policyholder dividend obligation			(120	)		(85	)
	Net unrealized appreciation		$	—		$	—
	The following table summarizes closed block operations for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Revenues:
	Premiums		$	61		$	66		$	73
	Net investment income			93			94			98
	Realized investment gains			1			—			1
	Realized losses credited to policyholder benefit obligation			(5	)		(4	)		(5	)
	Total revenues		$	150		$	156		$	167
	Benefits and expenses:
	Policy and contract benefits		$	124		$	123		$	134
	Change in future policyholder benefits and interest credited to policyholder accounts			(34	)		(29	)		(27	)
	Policyholder dividends			43			44			50
	Change in policyholder dividend obligation			(1	)		3			(8	)
	Other expenses			2			(2	)		1
	Total benefits and expenses		$	134		$	139		$	150
	Total revenues, net of benefits and expenses, before federal income tax expense		$	16		$	17		$	17
	Federal income tax expense			6			6			6
	Revenues, net of benefits and expenses and federal income tax expense		$	10		$	11		$	11
	Maximum future earnings from assets and liabilities:
	Beginning of period		$	182		$	193		$	204
	Change during period			(10	)		(11	)		(11	)
	End of period		$	172		$	182		$	193
	Cumulative closed block earnings from inception through December 31, 2014, 2013 and 2012 were higher than expected as determined in the actuarial calculation. Therefore, policyholder dividend obligations (excluding the adjustment for unrealized gains on available-for-sale securities) were $32 million, $28 million and $21 million as of December 31, 2014, 2013 and 2012, respectively.

ShortTerm_Debt

Short-Term Debt	12 Months Ended
	Dec. 31, 2014
Short-Term Debt	-11	Short-Term Debt
	The Company classifies debt as short-term if the maturity date at inception is less than one year.
	The following table summarizes the carrying value of short-term debt and weighted average annual interest rates, as of the dates indicated:
			December 31,
	(in millions)		2014		2013
	$600 million commercial paper program (0.20% and 0.24%, respectively)		$	264	$	278
	$400 million revolving variable rate line of credit (1.57% and 0.00%, respectively)			396		—
	Total short-term debt		$	660	$	278
	In November 2014, the Company entered into a $400 million unsecured revolving promissory note and line of credit agreement with its parent company, NFS. Outstanding principal balances of the line of credit bear interest at the rate of six-month London Interbank Offered Rate (“LIBOR”) plus 1.25%. Interest is due and payable as of the last day of each interest period, as defined in the agreement, while there are outstanding principal balances. Under the terms of the agreement, the Company may borrow, repay and re-borrow advances under the line of credit at any time prior to the termination of the note, which, among other conditions, is November 2015, subject to automatic renewal for additional one year periods unless either party terminates the agreement. In February 2015, the Company repaid $200 million of the outstanding balance.
	In March 2014, the Company renewed an agreement to extend its ability to borrow with the FHLB. This extension, which expires on March 27, 2015, allows the Company access to borrow up to $250 million, which would be collateralized by pledged securities. The Company had $8.5 billion and $4.3 billion in eligible collateral and no amounts outstanding under the agreement as of December 31, 2014 and 2013, respectively. Additionally, as part of the agreement, NLIC purchased $25 million in capital stock with the FHLB.
	NMIC, NFS, and NLIC have a $600 million revolving variable rate credit facility that matures on May 6, 2015. NLIC had no amounts outstanding under the facility as of December 31, 2014 and 2013.
	The Company has entered into an agreement with its custodial bank to borrow against the cash collateral that is posted in connection with its securities lending program. The maximum amount available under the agreement is $350 million. The borrowing rate on this program is equal to one-month U.S. LIBOR. The Company had no amounts outstanding under this agreement as of December 31, 2014 and 2013.
	The terms of each debt instrument contain various restrictive covenants, including, but not limited to, minimum statutory surplus and minimum net worth requirements, and maximum debt to statutory surplus leverage ratio requirements, as defined in the agreements. The Company was in compliance with all covenants as of December 31, 2014 and 2013.
	The amount of interest paid on short-term debt was immaterial in 2014, 2013 and 2012.

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2014
Long-Term Debt	-12	Long-Term Debt
	The following table summarizes the carrying value of long-term debt, as of the dates indicated:
			December 31,
	(in millions)		2014		2013
	8.15% surplus note, due June 26, 2032, payable to NFS		$	300	$	300
	7.50% surplus note, due December 17, 2031, payable to NFS			300		300
	6.75% surplus note, due December 23, 2033, payable to NFS			100		100
	Other			9		7
	Total long-term debt		$	709	$	707
	On December 31, 2010, Olentangy Reinsurance, LLC (“Olentangy”), a special purpose financial captive insurance company subsidiary of NLAIC domiciled in the State of Vermont, issued a variable funding surplus note due on December 31, 2040 to Nationwide Corporation, a majority-owned subsidiary of NMIC. In June 2013, the Company paid the outstanding balance of the surplus note. The Company made interest payments on the surplus note totaling $5 million during 2013 prior to the repayment of the outstanding balance. Payments of interest and principal under the notes require the prior approval of the State of Vermont.
	The Company made interest payments to NFS on surplus notes totaling $54 million for the years ended December 31, 2014, 2013 and 2012. Payments of interest and principal under the notes require the prior approval of the ODI.

Federal_Income_Taxes

Federal Income Taxes	12 Months Ended
	Dec. 31, 2014
Federal Income Taxes	-13	Federal Income Taxes
	The following table summarizes the components of federal income tax (benefit) expense for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Current tax expense (benefit)		$	5		$	(33	)	$	(144	)
	Deferred tax (benefit) expense			(152	)		346			243
	Total tax (benefit) expense		$	(147	)	$	313		$	99
	The following table summarizes how the total federal income tax (benefit) expense differs from the amount computed by applying the U.S. federal income tax rate to net (loss) income for the years ended:
			December 31,
			2014						2013						2012
	(in millions)		Amount			%			Amount			%			Amount			%
	Rate reconciliation:
	Computed (expected tax (benefit) expense)		$	(46	)		35	%	$	469			35	%	$	245			35	%
	Dividends received deduction			(87	)		66	%		(112	)		(8	)%		(75	)		(11	)%
	Tax credits			(53	)		41	%		(82	)		(6	)%		(85	)		(12	)%
	Other, net			39			(30	)%		38			2	%		14			2	%
	Total		$	(147	)		112	%	$	313			23	%	$	99			14	%
	The Company’s current federal income tax liability was $18 million and $13 million as of December 31, 2014 and 2013, respectively.
	The Company made immaterial payments for the year ended December 31, 2014 and received refunds of $107 million and $95 million for the years ended 2013 and 2012, respectively.
	During 2014 and 2013, the Company recorded a tax expense (benefit) of $16 million and $(13) million, respectively. These changes in estimates were primarily driven by differences in the Company’s separate account dividends received deduction (“DRD”) between the previous year’s estimate and the amount reported on the previous year’s tax return. No material changes in estimated income tax expense were recorded in 2012.
	As of December 31, 2014, the Company had gross federal net operating loss carryforwards of $332 million, which expire in 2028. In addition, the Company had $147 million in low-income-housing credit carryforwards, which expire between 2024 and 2034, and $155 million in alternative minimum tax credit carryforwards, which have an unlimited carryforward. In addition, the Company had $53 million in foreign tax credit carryforwards which expire between 2019 and 2024. The Company expects to fully utilize all carryforwards.
	The following table summarizes the tax effects of temporary differences that gave rise to significant components of the net deferred tax liability included in other liabilities in the consolidated balance sheets, as of the dates indicated:
			December 31,
	(in millions)		2014			2013
	Deferred tax assets
	Future policy benefits and claims		$	1,274		$	1,244
	Tax credit carryforwards			355			352
	Other			840			845
	Gross deferred tax assets		$	2,469		$	2,441
	Valuation allowance			(17	)		(17	)
	Net deferred tax assets		$	2,452		$	2,424
	Deferred tax liabilities
	Deferred policy acquisition costs		$	(1,113	)	$	(1,048	)
	Available-for-sale securities			(1,201	)		(821	)
	Derivatives, including embedded derivatives			(267	)		(600	)
	Other			(269	)		(255	)
	Gross deferred tax liabilities		$	(2,850	)	$	(2,724	)
	Net deferred tax liability		$	(398	)	$	(300	)
	In assessing the realizability of deferred tax assets, the Company considers whether it is more likely than not that some portion of the total gross deferred tax assets will not be realized. Valuation allowances are established when necessary to reduce the deferred tax assets to amounts expected to be realized. Based on the Company’s analysis, it is more likely than not that the results of future operations and the implementation of tax planning strategies will generate sufficient taxable income to enable the Company to realize the deferred tax assets for which the Company has not established valuation allowances.
	The following table is a rollforward of the beginning and ending uncertain tax positions, including permanent and temporary differences, but excluding interest and penalties:
	(in millions)		2014			2013			2012
	Balance at beginning of period		$	36		$	36		$	76
	Additions for current year tax positions			3			2			(2	)
	Additions for prior years tax positions			—			—			25
	Reductions for prior years tax positions			(1	)		(2	)		(63	)
	Balance at end of period		$	38		$	36		$	36
	The Company believes it is reasonably possible that the 2006 to 2010 IRS audit for the NLIC’s consolidated tax returns will be effectively settled within the next 12 months and as a result the liability for unrecognized tax benefits could decrease $15 million.
	The Company files income tax returns in the U.S. federal jurisdiction and various state jurisdictions. The Company is no longer subject to U.S. federal, state or local income tax examinations by tax authorities through the 2005 tax year. In 2013, the IRS commenced an examination of the Company’s U.S. income tax returns for the years 2009 through 2010. Any adjustments that may result from IRS examination of tax returns are not expected to have a material effect on the results of operations, cash flows or financial position of the Company.

Statutory_Financial_Informatio

Statutory Financial Information	12 Months Ended
	Dec. 31, 2014
Statutory Financial Information	-14	Statutory Financial Information
	Statutory Results
	The Company’s life insurance subsidiaries prepare their statutory financial statements in conformity with the statutory accounting practices prescribed and permitted by insurance regulatory authorities, subject to any deviations prescribed or permitted by the applicable state departments of insurance. Olentangy was granted a permitted practice from the State of Vermont that changed NLAIC’s valuation of this subsidiary by $66 million as of December 31, 2014 and 2013, which also allowed NLIC to admit additional deferred tax assets of $10 million as of December 31, 2014 and 2013. Statutory accounting practices focus on insurer solvency and differ materially from GAAP primarily due to charging policy acquisition and other costs to expense as incurred, establishing future policy benefits and claims reserves based on different actuarial assumptions, excluding certain assets from statutory admitted assets and valuing investments and establishing deferred taxes on a different basis.
	The following table summarizes the statutory net income (loss) and statutory capital and surplus for the Company’s primary life insurance subsidiaries for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Statutory net income (loss)
	NLIC		$	341		$	262		$	764
	NLAIC		$	(122	)	$	(103	)	$	(54	)
	Statutory capital and surplus
	NLIC		$	4,408		$	3,550		$	3,837
	NLAIC		$	691		$	534		$	311
	Dividend Restrictions
	The payment of dividends by NLIC is subject to restrictions set forth in the insurance laws and regulations of the State of Ohio, its domiciliary state. The State of Ohio insurance laws require Ohio-domiciled life insurance companies to seek prior regulatory approval to pay a dividend or distribute cash or other property if the fair market value thereof, together with that of other dividends or distributions made in the preceding twelve months, exceeds the greater of (1) 10% of statutory-basis policyholders’ surplus as of the prior December 31 or (2) the statutory-basis net income of the insurer for the prior year. During the years ended December 31, 2014 and 2013, NLIC did not pay any dividends to NFS. During the year ended December 31, 2012, NLIC paid a cash dividend of $40 million to NFS. As of January 1, 2015, NLIC has the ability to pay dividends to NFS totaling $441 million without obtaining prior approval.
	The State of Ohio insurance laws also require insurers to seek prior regulatory approval for any dividend paid from other than earned surplus. Earned capital and surplus is defined under the State of Ohio insurance laws as the amount equal to the Company’s unassigned funds as set forth in its most recent statutory financial statements, including net unrealized capital gains and losses or revaluation of assets. Additionally, following any dividend, an insurer’s policyholder capital and surplus must be reasonable in relation to the insurer’s outstanding liabilities and adequate for its financial needs. The payment of dividends by the Company may also be subject to restrictions set forth in the insurance laws of the State of New York that limit the amount of statutory profits on the Company’s participating policies (measured before dividends to policyholders) available for the benefit of the Company and its stockholders.
	The Company currently does not expect such regulatory requirements to impair the ability to pay operating expenses and dividends in the future.
	Regulatory Risk-Based Capital
	The National Association of Insurance Commissioners’ (“NAIC”) Risk-Based Capital (“RBC”) model law requires every insurer to calculate its total adjusted capital and RBC requirement to ensure insurer solvency. Regulatory guidelines provide for an insurance commissioner to intervene if the insurer experiences financial difficulty, as evidenced by a company’s total adjusted capital falling below established relationships to required RBC. The model includes components for asset risk, liability risk, interest rate exposure and other factors. The State of Ohio, where NLIC and NLAIC are domiciled, imposes minimum RBC requirements that are developed by the NAIC. The formulas in the model for determining the amount of RBC specify various weighting factors that are applied to financial balances or various levels of activity based on the perceived degree of risk. Regulatory compliance is determined by a ratio of total adjusted capital to authorized control level RBC, as defined by the NAIC. Companies below specific trigger points or ratios are classified within certain levels, all of which require specified corrective action. NLIC, NLAIC and Olentangy each exceeded the minimum RBC requirements for all periods presented.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions	-15	Related Party Transactions
	The Company has entered into significant, recurring transactions and agreements with NMIC, other affiliates and subsidiaries as a part of its ongoing operations. These include annuity and life insurance contracts, employee benefit plans, office space cost sharing arrangements, and agreements related to reinsurance, cost sharing, administrative services, marketing, intercompany loans, intercompany repurchases, cash management services and software licensing. Measures used to allocate expenses among companies include individual employee estimates of time spent, special cost studies, the number of full-time employees, commission expense and other methods agreed to by the participating companies.
	In addition, Nationwide Services Company, LLC (“NSC”), a subsidiary of NMIC, provides data processing, systems development, hardware and software support, telephone, mail and other services to the Company, based on specified rates for units of service consumed. For the years ended December 31, 2014, 2013 and 2012, the Company made payments to NMIC and NSC totaling $275 million, $277 million and $283 million, respectively.
	The Company has issued group annuity and life insurance contracts and performs administrative services for various employee benefit plans sponsored by NMIC or its affiliates. Total account values of these contracts were $3.3 billion as of December 31, 2014 and 2013. Total revenues from these contracts were $131 million, $137 million and $140 million for the years ended December 31, 2014, 2013 and 2012, respectively, and include policy charges, net investment income from investments backing the contracts and administrative fees. Total interest credited to the account balances was $109 million for the years ended December 31, 2014 and 2013, and $113 million for the year ended December 31, 2012. The terms of these contracts are materially consistent with what the Company offers to unaffiliated parties.
	The Company has a cost sharing arrangement with NMIC to occupy office space. The Company made payments to NMIC of $16 million for the years ended December 31, 2014 and 2013, and $15 million for the year ended December 31, 2012. In addition, an affiliate of NMIC has a cost sharing arrangement with the Company to occupy office space.
	NLIC has a reinsurance agreement with NMIC whereby all of NLIC’s accident and health business not ceded to unaffiliated reinsurers is ceded to NMIC on a modified coinsurance basis. Either party may terminate the agreement on January 1 of any year with prior notice. Under a modified coinsurance agreement, the ceding company retains invested assets, and investment earnings are paid to the reinsurer. Under the terms of NLIC’s agreements, the investment risk associated with changes in interest rates is borne by the reinsurer. The ceding of risk does not discharge the original insurer from its primary obligation to the policyholder. The Company believes that the terms of the modified coinsurance agreements are consistent in all material respects with what the Company could have obtained with unaffiliated parties. Revenues ceded to NMIC for the years ended December 31, 2014, 2013 and 2012 were $208 million, $179 million and $161 million, respectively, while benefits, claims and expenses ceded during these years were $217 million, $178 million and $167 million, respectively.
	Funds of Nationwide Funds Group (“NFG”), an affiliate, are offered to the Company’s customers as investment options in certain of the Company’s products. As of December 31, 2014 and 2013, customer allocations to NFG funds totaled $58.1 billion and $53.2 billion, respectively. For the years ended December 31, 2014, 2013 and 2012, NFG paid the Company $185 million, $163 million and $144 million, respectively, for the distribution and servicing of these funds.
	Amounts on deposit with NCMC for the benefit of the Company were $636 million and $228 million as of December 31, 2014 and 2013, respectively.
	Refer to Note 12 for discussion of variable funding surplus note between Olentangy Reinsurance, LLC and Nationwide Corporation.
	Nationwide Bank has a line of credit agreement with NLIC that allows the Bank access to borrow up to $50 million from NLIC. The borrowing rate on the line of credit is equal to the daily Prime Rate. The Bank had no amounts outstanding under this agreement as of December 31, 2014 and 2013.
	Certain annuity products are sold through affiliated companies, which are also subsidiaries of NFS. Total commissions and fees paid to these affiliates were $57 million for the year ended December 31, 2014, and $54 million for the years ended December 31, 2013 and 2012.
	The Company provides financing to Nationwide Realty Investors, LTD, a subsidiary of NMIC. As of December 31, 2014 and 2013, the Company had notes receivable outstanding of $142 million and $146 million, respectively.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2014
Contingencies	-16	Contingencies
	Legal and Regulatory Matters
	The Company is subject to legal and regulatory proceedings in the ordinary course of its business. The Company’s legal and regulatory matters include proceedings specific to the Company and other proceedings generally applicable to business practices in the industries in which the Company operates. These matters are subject to many uncertainties, and given their complexity and scope, their outcomes cannot be predicted. Regulatory proceedings could also affect the outcome of one or more of the Company’s litigation matters. Furthermore, it is often not possible to determine the ultimate outcomes of the pending regulatory investigations and legal proceedings or to provide reasonable ranges of potential losses with any degree of certainty. Some matters, including certain of those referred to below, are in very preliminary stages, and the Company does not have sufficient information to make an assessment of the plaintiffs’ claims for liability or damages. In some of the cases seeking to be certified as class actions, the court has not yet decided whether a class will be certified or (in the event of certification) the size of the class and class period. In many of the cases, the plaintiffs are seeking undefined amounts of damages or other relief, including punitive damages and equitable remedies, which are difficult to quantify and cannot be defined based on the information currently available. The Company believes, however, that based on currently known information, the ultimate outcome of all pending legal and regulatory matters is not likely to have a material adverse effect on the Company’s consolidated financial position. Nonetheless, given the large or indeterminate amounts sought in certain of these matters and the inherent unpredictability of litigation, it is possible that such outcomes could materially affect the Company’s consolidated financial position or results of operations in a particular quarter or annual period.
	The various businesses conducted by the Company are subject to oversight by numerous federal and state regulatory entities, including but not limited to the U.S. Securities and Exchange Commission, the Financial Industry Regulatory Authority, the Department of Labor, the IRS and state insurance authorities. Such regulatory entities may, in the normal course, be engaged in general or targeted inquiries, examinations and investigations of the Company and/or its affiliates. The financial services industry has been the subject of increasing scrutiny in connection with a broad spectrum of regulatory issues; with respect to all such scrutiny directed at the Company and/or its affiliates, the Company is cooperating with regulators. The Company will cooperate with NMIC insofar as any inquiry, examination or investigation encompasses NMIC’s operations.
	On August 15, 2001, NFS and NLIC were named in a lawsuit filed in the United States District Court for the District of Connecticut entitled Lou Haddock, as trustee of the Flyte Tool & Die, Incorporated Deferred Compensation Plan, et al v. Nationwide Financial Services, Inc. and Nationwide Life Insurance Company. On November 18, 2009, the plaintiffs filed a sixth amended complaint amending the list of named plaintiffs and claiming to represent a class of qualified retirement plan trustees under the Employee Retirement Income Security Act of 1974 (“ERISA”) that purchased variable annuities from NLIC. The plaintiffs allege that they invested ERISA plan assets in their variable annuity contracts and that NLIC and NFS breached ERISA fiduciary duties by allegedly accepting service payments from certain mutual funds. The complaint seeks damages in an amount equivalent to some or all of the payments allegedly received by NFS and NLIC, other unspecified relief for restitution, declaratory and injunctive relief and attorneys’ fees. On November 6, 2009, the Court granted the plaintiffs’ motion for class certification. On October 21, 2010, the District Court dismissed NFS from the lawsuit. On February 6, 2012, the Second Circuit Court of Appeals vacated the November 6, 2009 order granting class certification and remanded the case back to the District Court for further consideration. On September 6, 2013, the District Court granted the plaintiffs’ motion for class certification. On December 11, 2014, the plaintiffs filed a seventh amended complaint adding another sub class of defendants that held trust platform products. On December 11, 2014, the plaintiffs filed a motion for preliminary approval of settlement. On January 5, 2015, the Court signed the Order Preliminarily Approving Settlement and Approving Form and Manner of Notice. A Fairness Hearing has been set for March 31, 2015. NLIC has made adequate provision for all probable and reasonably estimable losses associated with this settlement.
	Lehman Brothers Holdings, Inc. (Debtors) and Giddens, James v NLIC and NMIC, et al. In 2012, the Plaintiff, Debtor in Possession Lehman Brothers Special Financing, Inc., filed a class action in the United States Bankruptcy Court for the Southern District of New York seeking the recovery of certain assets from approximately 200 defendants, including NLIC and NMIC (the “Distributed Action”). The claims against NLIC and NMIC arise from the bankruptcy filings in 2008 of the Plaintiff and its parent company, Lehman Brothers Holding, Inc., which triggered the early termination of two collateralized debt obligation transactions, resulting in payments to NLIC and NMIC. The Plaintiff seeks to have certain sums returned to the bankruptcy estate in addition to prejudgment interest and costs. In 2013, Plaintiff sent correspondence to all defendants inviting settlement discussions and served NMIC and NLIC with a “SPV Derivatives ADR Notice,” formally starting the Alternative Dispute Resolution process. NMIC and NLIC responded, taking part in the ADR process, including a mediation. On July 17, 2014, the parties reached a settlement of this matter. On December 8, 2014, the settlement agreements were finalized and executed. Nationwide has issued the settlement payment, was dismissed from the case with prejudice on December 31, 2014, and this matter will shortly be closed.
	Indemnifications
	In the normal course of business, the Company provides standard indemnifications to contractual counterparties. The types of indemnifications typically provided include breaches of representations and warranties, taxes and certain other liabilities, such as third party lawsuits. The indemnification clauses are often standard contractual terms and are entered into in the normal course of business based on an assessment that the risk of loss would be remote. The terms of the indemnifications vary in duration and nature. In many cases, the maximum obligation is not explicitly stated, and the contingencies triggering the obligation to indemnify have not occurred and are not expected to occur. Consequently, the amount of the obligation under such indemnifications is not determinable. Historically, the Company has not made any material payments pursuant to these obligations.
	Tax Matters
	The Company’s federal income tax returns are routinely audited by the IRS. The Company has established tax reserves as described in Note 2. The Company believes its tax reserves reasonably provide for potential assessments that may result from IRS examinations and other tax-related matters for all open tax years.

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2014
Reinsurance	-17	Reinsurance
	The following table summarizes the effects of reinsurance on life, accident and health insurance in force and premiums for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Premiums
	Direct		$	1,178		$	1,015		$	890
	Assumed from other companies			—			—			—
	Ceded to other companies			(347	)		(291	)		(255	)
	Net		$	831		$	724		$	635
	Life, accident and health insurance in force
	Direct		$	241,936		$	228,095		$	216,002
	Assumed from other companies			5			6			5
	Ceded to other companies			(59,588	)		(58,310	)		(59,895	)
	Net		$	182,353		$	169,791		$	156,112
	Amounts recoverable under reinsurance contracts totaled $704 million, $675 million and $684 million as of December 31, 2014, 2013 and 2012, respectively, and are included in other assets in the consolidated balance sheets.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Information	-18	Segment Information
	Management views the Company’s business primarily based on its underlying products and uses this basis to define its four reportable segments: Individual Products and Solutions-Annuity (formerly named Individual Investments), Retirement Plans, Individual Products and Solutions-Life and NBSG (formerly named Individual Protection) and Corporate and Other.
	The primary segment profitability measure that management uses is a non-GAAP financial measure called pre-tax operating earnings (loss), which is calculated by adjusting income before federal income taxes to exclude: (1) net realized investment gains and losses, except for operating items (trading portfolio realized gains and losses, trading portfolio valuation changes and net realized gains and losses related to hedges on GMDB contracts); (2) the adjustment to amortization of DAC and other related expenses related to net realized investment gains and losses; and (3) net losses attributable to noncontrolling interest.
	Due to a change in the manner in which we view our reportable segments, certain prior period amounts have been restated.
	Individual Products and Solutions-Annuity
	The Individual Products & Solutions - Annuity segment consists of individual annuity products marketed under the Nationwide DestinationSM and other Nationwide-specific or private label brands. Deferred annuity contracts provide the customer with tax-deferred accumulation of savings and flexible payout options including lump sum, systematic withdrawal or a stream of payments for life. In addition, deferred variable annuity contracts provide the customer with access to a wide range of investment options and asset protection features, while deferred fixed annuity contracts generate a return for the customer at a specified interest rate fixed for prescribed periods. Immediate annuities differ from deferred annuities in that the initial premium is exchanged for a stream of income for a certain period and/or for the owner’s lifetime without future access to the original investment. The majority of assets and recent sales for the Individual Products & Solutions - Annuity segment consist of deferred variable annuities.
	Retirement Plans
	The Retirement Plans segment is comprised of the private and public sector retirement plans businesses. The private sector business primarily includes Internal Revenue Code (“IRC”) Section 401 qualified plans funded through fixed and variable group annuity contracts issued through NLIC. The public sector business primarily includes IRC Section 457 (b) and Section 401(a) governmental plans, both in the form of full-service arrangements that provide plan administration along with fixed and variable group annuities, as well as administration-only business. Across the public and private sector business Nationwide Investment Advisors managed account services are also available. The Retirement Plans segment also includes stable value wrap products and solutions.
	Individual Products and Solutions-Life and NBSG
	The Individual Products & Solutions - Life and NBSG segment consists of life insurance products, including individual variable universal life, COLI and BOLI products, traditional life insurance products, fixed universal life insurance products and indexed universal life insurance products. Life insurance products provide a death benefit and, for certain products, allow the customer to build cash value on a tax-advantaged basis.
	Corporate and Other
	The Corporate and Other segment includes non-operating realized gains and losses and related amortization, including mark-to-market adjustments on embedded derivatives, net of economic hedges, related to products with living benefits included in the Individual Products & Solutions - Annuity segment, other-than-temporary impairment losses, and other revenues and expenses not allocated to other segments. Additionally, this segment includes the funding agreements with the FHLB, as well as the medium-term note (“MTN”) program that concluded in the fourth quarter of 2012.
	The following tables summarize the Company’s business segment operating results for the years ended:
	(in millions)		Individual			Retirement			Individual		Corporate			Total
			Products and			Plans			Products and		and Other
			Solutions-						Solutions-Life
			Annuity						and NBSG
	December 31, 2014
	Revenues:
	Policy charges		$	1,175		$	107		$	783	$	—		$	2,065
	Premiums			518			—			284		29			831
	Net investment income			546			750			565		39			1,900
	Non-operating net realized investment losses, including other-than-temporary impairment losses1			—			—			—		(1,051	)		(1,051	)
	Other revenues2			(38	)		—			12		10			(16	)
	Total revenues		$	2,201		$	857		$	1,644	$	(973	)	$	3,729
	Benefits and expenses:
	Interest credited to policyholder accounts		$	370		$	482		$	231	$	13		$	1,096
	Benefits and claims			828			—			644		30			1,502
	Amortization of DAC			120			(28	)		122		(7	)		207
	Other expenses, net of deferrals			300			153			348		254			1,055
	Total benefits and expenses		$	1,618		$	607		$	1,345	$	290		$	3,860
	Income before federal income taxes and noncontrolling interests		$	583		$	250		$	299	$	(1,263	)	$	(131	)
	Less:    non-operating net realized investment losses, including other-than-temporary impairment losses1			—			—			—		1,051
	Less:    adjustment to amortization of DAC and other related expenses related to net realized investment gains and losses			—			—			—		(11	)
	Less:    net loss attributable to noncontrolling interest			—			—			—		94
	Pre-tax operating earnings (loss)		$	583		$	250		$	299	$	(129	)
	Assets as of year end		$	72,429		$	30,744		$	29,322	$	11,029		$	143,524
	1	Excluding operating items (trading portfolio realized gains and losses, trading portfolio valuation changes and net realized gains and losses related to hedges on GMDB contracts).
	2	Includes operating items discussed above.
	(in millions)		Individual			Retirement			Individual		Corporate			Total
			Products and			Plans			Products and		and Other
			Solutions-						Solutions-Life
			Annuity						and NBSG
	December 31, 2013
	Revenues:
	Policy charges		$	1,021		$	101		$	727	$	—		$	1,849
	Premiums			416			—			282		26			724
	Net investment income			546			743			544		16			1,849
	Non-operating net realized investment gains, including other-than-temporary impairment losses1			—			—			—		783			783
	Other revenues2			(109	)		—			6		15			(88	)
	Total revenues		$	1,874		$	844		$	1,559	$	840		$	5,117
	Benefits and expenses:
	Interest credited to policyholder accounts		$	377		$	473		$	213	$	4		$	1,067
	Benefits and claims			694			—			636		24			1,354
	Amortization of DAC			185			(2	)		125		66			374
	Other expenses, net of deferrals			295			151			347		188			981
	Total benefits and expenses		$	1,551		$	622		$	1,321	$	282		$	3,776
	Income before federal income taxes and noncontrolling interests		$	323		$	222		$	238	$	558		$	1,341
	Less:    non-operating net realized investment gains, including other-than-temporary impairment losses1			—			—			—		(783	)
	Less:    adjustment to amortization of DAC and other related expenses related to net realized investment gains and losses			—			—			—		70
	Less:    net loss attributable to noncontrolling interest			—			—			—		82
	Pre-tax operating earnings (loss)		$	323		$	222		$	238	$	(73	)
	Assets as of year end		$	68,805		$	29,904		$	27,183	$	7,553		$	133,445
	1	Excluding operating items (trading portfolio realized gains and losses, trading portfolio valuation changes and net realized gains and losses related to hedges on GMDB contracts).
2	Includes operating items discussed above.
(in millions)		Individual			Retirement			Individual		Corporate			Total
		Products and			Plans			Products and		and Other
		Solutions-						Solutions-Life
		Annuity						and NBSG
December 31, 2012
Revenues:
Policy charges		$	899		$	94		$	677	$	—		$	1,670
Premiums			334			—			274		27			635
Net investment income			551			736			534		4			1,825
Non-operating net realized investment gains, including of other-than-temporary impairment losses1			—			—			—		427			427
Other revenues2			(124	)		—			—		23			(101	)
Total revenues		$	1,660		$	830		$	1,485	$	481		$	4,456
Benefits and expenses:
Interest credited to policyholder accounts		$	375		$	457		$	199	$	7		$	1,038
Benefits and claims			613			—			588		26			1,227
Amortization of DAC			185			14			150		226			575
Other expenses, net of deferrals			266			164			307		180			917
Total benefits and expenses		$	1,439		$	635		$	1,244	$	439		$	3,757
Income before federal income taxes and noncontrolling interests		$	221		$	195		$	241	$	42		$	699
Less:    non-operating net realized investment gains, including other-than-temporary impairment losses1			—			—			—		(427	)
Less:    adjustment to amortization of DAC and other related expenses related to net realized investment gains and losses			—			—			—		243
Less:    net loss attributable to noncontrolling interest			—			—			—		61
Pre-tax operating earnings (loss)		$	221		$	195		$	241	$	(81	)
Assets as of year end		$	58,707		$	27,842		$	25,301	$	8,320		$	120,170
1	Excluding operating items (trading portfolio realized gains and losses, trading portfolio valuation changes and net realized gains and losses related to hedges on GMDB contracts).
2	Includes operating items discussed above.

Consolidated_Summary_of_Invest

Consolidated Summary of Investments - Other Than Investments in Related Parties	12 Months Ended
	Dec. 31, 2014
Consolidated Summary of Investments - Other Than Investments in Related Parties	Schedule I Consolidated Summary of Investments – Other Than Investments in Related Parties
	As of December 31, 2014 (in millions)
	Column A		Column B		Column C		Column D
	Type of investment		Cost		Fair value		Amount at
							which shown
							in the
							consolidated
							balance sheet
	Fixed maturity securities, available-for-sale:
	Bonds:
	U.S. government and agencies		$	448	$	527	$	527
	Obligations of states, political subdivisions and foreign governments			1,966		2,285		2,285
	Public utilities			2,969		3,228		3,228
	All other corporate, mortgage-backed and asset-backed securities			27,815		29,378		29,378
	Total fixed maturity securities, available-for-sale		$	33,198	$	35,418	$	35,418
	Equity securities, available-for-sale:
	Common stocks:
	Industrial, miscellaneous and all other		$	6	$	16	$	16
	Nonredeemable preferred stocks			—		5		5
	Total equity securities, available-for-sale		$	6	$	21	$	21
	Trading assets			20		21		21
	Mortgage loans, net of allowance			7,296				7,270	1
	Policy loans			992				992
	Other investments			780				780
	Short-term investments			935				935
	Total investments		$	43,227			$	45,437
	1	Difference from Column B primarily is attributable to valuation allowances due to impairments on mortgage loans (see Note 6 to the audited consolidated financial statements).
	See accompanying notes to consolidated financial statements and report of independent registered public accounting firm.

Supplementary_Insurance_Inform

Supplementary Insurance Information	12 Months Ended
	Dec. 31, 2014
Supplementary Insurance Information	Schedule III Supplementary Insurance Information
	As of December 31, 2014, 2013 and 2012 and for each of the years then ended (in millions)
	Column A		Column B			Column C		Column D			Column E		Column F
	Year: Segment		Deferred			Future policy		Unearned			Other policy		Premium
			policy			benefits, losses,		premiums1			claims and		revenue
			acquisition			claims and					benefits payable1
			costs			loss expenses
	2014
	IPS - Annuity		$	2,495		$	12,619						$	518
	Retirement Plans			216			14,905							—
	IPS - Life and NBSG			1,717			10,763							284
	Corporate and Other			(365	)		2,443							29
	Total		$	4,063		$	40,730						$	831
	2013
	IPS - Annuity		$	2,214		$	10,985						$	416
	Retirement Plans			179			14,313							—
	IPS - Life and NBSG			1,557			10,068							282
	Corporate and Other			(172	)		1,399							26
	Total		$	3,778		$	36,765						$	724
	2012
	IPS - Annuity		$	2,110		$	12,214						$	334
	Retirement Plans			168			13,628							—
	IPS - Life and NBSG			1,442			9,564							301
	Corporate and Other			(471	)		748							—
	Total		$	3,249		$	36,154						$	635
	Column A		Column G			Column H		Column I			Column J		Column K
	Year: Segment		Net			Benefits, claims,		Amortization			Other		Premiums
			investment			losses and		of deferred policy			operating		written
			income2			settlement expenses		acquisition costs			expenses2
	2014
	IPS - Annuity		$	546		$	1,198	$	120		$	300
	Retirement Plans			750			482		(28	)		153
	IPS - Life and NBSG			565			875		122			348
	Corporate and Other			39			43		(7	)		254
	Total		$	1,900		$	2,598	$	207		$	1,055
	2013
	IPS - Annuity		$	546		$	1,071	$	185		$	295
	Retirement Plans			743			473		(2	)		151
	IPS - Life and NBSG			544			849		125			347
	Corporate and Other			16			28		66			188
	Total		$	1,849		$	2,421	$	374		$	981
	2012
	IPS - Annuity		$	551		$	988	$	185		$	266
	Retirement Plans			736			457		14			164
	IPS - Life and NBSG			536			787		150			307
	Corporate and Other			2			33		226			180
	Total		$	1,825		$	2,265	$	575		$	917
	1	Unearned premiums and other policy claims and benefits payable are included in Column C amounts.
	2	Allocations of net investment income and certain operating expenses are based on numerous assumptions and estimates, and reported segment operating results would change if different methods were applied.
	See accompanying notes to consolidated financial statements and report of independent registered public accounting firm.

Reinsurance1

Reinsurance	12 Months Ended
	Dec. 31, 2014
Reinsurance	Schedule IV Reinsurance
	As of December 31, 2014, 2013 and 2012 and for each of the years then ended (in millions)
	Column A		Column B		Column C			Column D		Column E		Column F
			Gross		Ceded to			Assumed		Net		Percentage
			amount		other			from other		amount		of amount
					companies			companies				assumed
												to net
	2014
	Life, accident and health insurance in force		$	241,936	$	(59,588	)	$	5	$	182,353		—
	Premiums:
	Life insurance1		$	888	$	(57	)	$	—	$	831		—
	Accident and health insurance			290		(290	)		—		—		—
	Total		$	1,178	$	(347	)	$	—	$	831		—
	2013
	Life, accident and health insurance in force		$	228,095	$	(58,310	)	$	6	$	169,791		—
	Premiums:
	Life insurance1		$	783	$	(59	)	$	—	$	724		—
	Accident and health insurance			232		(232	)		—		—		—
	Total		$	1,015	$	(291	)	$	—	$	724		—
	2012
	Life, accident and health insurance in force		$	216,002	$	(59,895	)	$	5	$	156,112		—
	Premiums:
	Life insurance1		$	701	$	(66	)	$	—	$	635		—
	Accident and health insurance			189		(189	)		—		—		—
	Total		$	890	$	(255	)	$	—	$	635		—
	1	Primarily represents premiums from traditional life insurance and life-contingent immediate annuities and excludes deposits on investment and universal life insurance products.
	See accompanying notes to consolidated financial statements and report of independent registered public accounting firm.

Valuation_and_Qualifying_Accou

Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts	Schedule V Valuation and Qualifying Accounts
	Years ended December 31, 2014, 2013 and 2012 (in millions)
	Column A		Column B		Column C					Column D		Column E
	Description		Balance at		Charged to			Charged to		Deductions1		Balance at
			beginning		costs and			other				end of
			of period		expenses			accounts				period
	2014
	Valuation allowances - mortgage loans		$	35	$	(8	)	$	—	$	1	$	26
	2013
	Valuation allowances - mortgage loans		$	44	$	(4	)	$	—	$	5	$	35
	2012
	Valuation allowances - mortgage loans		$	60	$	1		$	—	$	17	$	44
	1	Amounts generally represent payoffs, sales and recoveries.
	See accompanying notes to consolidated financial statements and report of independent registered public accounting firm.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Basis of Presentation	Basis of Presentation
	The consolidated financial statements include the accounts of NLIC and companies in which NLIC directly or indirectly has a controlling financial interest. The consolidated financial statements include majority-owned subsidiaries and consolidated variable interest entities (“VIEs”). All significant intercompany accounts and transactions have been eliminated.
	Entities in which NLIC does not have a controlling interest, but the Company has significant influence over the operating and financing decisions, and also certain other investments, are reported using the equity method.
Use of Estimates	Use of Estimates
	The Company’s consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”). The preparation of the consolidated financial statements in accordance with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Significant estimates include the balance and amortization of deferred policy acquisition costs (“DAC”), legal and regulatory reserves, certain investment and derivative valuations, future policy benefits and claims including the valuation of embedded derivatives resulting from living benefit guarantees on variable annuity contracts, goodwill, provision for income taxes and valuation of deferred tax assets. Actual results could differ significantly from those estimates.
Revenues and Benefits	Revenues and Benefits
	Investment and universal life insurance products. Investment products are long-duration contracts that do not subject the Company to significant risk arising from mortality (the incidence of death) or morbidity (the incidence of disability resulting from disease or physical impairment). These include variable and fixed deferred annuity contracts in the accumulation phase with both individuals and groups, as well as certain annuities without life contingencies. Universal life insurance products include long-duration insurance contracts that do not have fixed or guaranteed terms. These include universal life insurance, variable universal life insurance, COLI, bank-owned life insurance (“BOLI”) and other interest-sensitive life insurance policies. Revenues for investment products and universal life insurance products consist of net investment income, surrender charges and other policy charges earned and assessed against policy account balances during the period. Policy charges are assessed on a daily or monthly basis and are recognized as revenue when assessed and earned. Assessments for services provided in future periods are recorded as unearned revenue and recognized as revenue over the periods benefited. Surrender charges are recognized as revenue upon surrender of a contract in accordance with contractual terms. Policy benefits and claims that are charged to expense include interest credited to policyholder accounts and benefits and claims incurred in the period in excess of related policyholder accounts.
	Traditional life insurance products. Traditional life insurance products include those products with fixed and guaranteed terms, primarily consisting of whole life insurance, term life insurance and certain annuities with life contingencies. Premiums for traditional life insurance products are generally recognized as revenue when due. For certain annuities with life contingencies, any excess of gross premium over the net premium is deferred and recognized with the amount of expected future benefits. Benefits and expenses are associated with earned premiums so that profits are recognized over the life of the contract. This association is accomplished through the provision for future policy benefits and the deferral and amortization of policy acquisition costs.
Future Policy Benefits and Claims	Future Policy Benefits and Claims
	Investment and universal life insurance products. The Company calculates its liability for future policy benefits and claims for investment products in the accumulation phase and for universal life insurance policies at the policy accrued account balance, which represents participants’ net deposits adjusted for investment performance, interest credited and applicable contract charges.
	The Company offers certain universal life insurance and variable universal life insurance with no-lapse guarantees and variable annuity products with guaranteed minimum death benefits (“GMDB”) and/or guaranteed minimum income benefits (“GMIB”). Liabilities for these guarantees are calculated by multiplying the current benefit ratio by the cumulative assessments recorded from contract inception through the balance sheet date less the cumulative guaranteed benefit payments plus interest. The Company annually evaluates its experience and assumptions and adjusts the benefit ratio as appropriate. If experience or assumption changes result in a new benefit ratio, the reserves are adjusted to reflect the changes with a related charge or credit to other benefits and claims in the period of evaluation. Determination of the expected benefit payments and assessments are based on a range of scenarios and assumptions, including those related to market rates of return and volatility, contract surrenders and mortality experience. The accounting for these guarantees impacts estimated gross profits used to calculate the balance and amortization of DAC and other expenses. Refer to Note 4 for further discussion of these guarantees.
	Guarantees to variable annuity contractholders can include a return of no less than the total deposits made on the contract less any customer withdrawals, total deposits made on the contract less any customer withdrawals plus a minimum return, or the highest contract value on a specified anniversary date minus any customer withdrawals following the contract anniversary. In addition, these guarantees can include benefits payable in the event of death, upon annuitization, upon periodic withdrawal or at specified dates during the accumulation period. Refer to Note 4 for further discussion of these guarantees.
	The Company’s guaranteed minimum accumulation benefit (“GMAB”) and guaranteed living withdrawal benefit (“GLWB”) living benefit guarantees represent embedded derivatives in variable annuity contracts that are required to be separated from, and valued apart from, the host variable annuity contracts. The embedded derivatives are held at fair value and include the present value of attributed fees. Subsequent changes in the fair value of the embedded derivatives are recognized in earnings as a component of net realized investment gains and losses. The fair value of the embedded derivatives is calculated based on a combination of capital market and actuarial assumptions. Projections of cash flows inherent in the valuation of the embedded derivatives incorporate numerous assumptions including, but not limited to, mortality, lapse rates, index volatility, benefit utilization and discounting. Benefit utilization includes wait period (the number of years the policyholder is assumed to wait prior to beginning withdrawals once eligible) and efficiency of benefit utilization (the percent of the maximum permitted withdrawal that a policyholder takes). Discounting includes liquidity and non-performance risk (the risk that the liability will not be fulfilled) and affects the value at which the liability is transferred. The assumptions used to calculate the fair value of embedded derivatives are reviewed as part of an annual comprehensive study of assumptions. Quarterly, consideration is given as to whether adjustments to these assumptions are necessary.
	The Company’s equity indexed products (life and annuity) have the policyholders’ interest credits based on market performance with caps and floors. The interest credits represent embedded derivatives within the insurance contract and therefore are required to be separated from, and valued apart from, the host contracts. The embedded derivatives are held at fair value. Subsequent changes in the fair value of the embedded derivatives are recognized in earnings as a component of interest credited. The fair value of the embedded derivatives is calculated based on a combination of capital market and actuarial assumptions. Projections of cash flows inherent in the valuation of the embedded derivative incorporate numerous assumptions including, but not limited to, mortality, lapse rates and index volatility. The assumptions used to calculate the fair value of embedded derivatives are reviewed as part of an annual comprehensive study of assumptions. Quarterly, consideration is given as to whether adjustments to these assumptions are necessary.
	Traditional life insurance products. The process of calculating reserve amounts for traditional life insurance products involves the use of a number of assumptions, including those related to persistency, mortality, morbidity, interest rates (the rates expected to be paid or received on financial instruments) and certain other expenses.
	The liability for future policy benefits and claims for traditional life insurance policies was determined using the net level premium method, with weighted average interest rates of 6.6% and estimates of mortality, morbidity, investment yields and persistency that were used or being experienced at the time the policies were issued, with a provision for adverse deviation.
	The liability for future policy benefits for certain annuities with life contingencies was calculated using the present value of future benefits and certain expenses, discounted using weighted average interest rates of 4.8% with a provision for adverse deviation.
	The Company issues fixed and floating rate funding agreements to the Federal Home Loan Bank of Cincinnati (“FHLB”). The liability for such funding agreements is recorded in future policy benefits and claims at amortized cost. The amount of collateralized funding agreements outstanding with the FHLB as of December 31, 2014 and 2013 was $1.8 billion and $913 million, respectively. In connection with an FHLB requirement for funding agreements, the Company held $35 million and $18 million of FHLB stock as of December 31, 2014 and 2013, respectively.
Reinsurance ceded	Reinsurance ceded
	The Company cedes insurance to other companies in order to limit potential losses and to diversify its exposures. Such agreements do not relieve the original insurer from its primary obligation to the policyholder in the event the reinsurer is unable to meet the obligations it has assumed. Reinsurance premiums ceded and reinsurance recoveries on benefits and claims incurred are deducted from the respective income and expense accounts. Assets and liabilities related to reinsurance ceded are reported in the consolidated balance sheets on a gross basis, separately from the related future policy benefits and claims of the Company.
Deferred Policy Acquisition Costs	Deferred Policy Acquisition Costs
	The Company has deferred certain acquisition costs that are directly related to the successful acquisition of new and renewal insurance and investment contracts. The methods and assumptions used to amortize and assess recoverability of the DAC balance depend on the type of product.
	Investment and universal life insurance products. For certain investment and universal life insurance products, DAC is amortized with interest over the lives of the policies in relation to the present value of estimated gross profits, which is determined primarily from projected interest margins, policy charges and net realized investment gains and losses, less policy benefits and other expenses. The DAC asset related to investment and universal life insurance products is adjusted to reflect the impact of unrealized gains and losses on available-for-sale securities, with the corresponding adjustment recorded in accumulated other comprehensive income (“AOCI”). This adjustment to DAC represents the change in amortization that would have been required as a charge or credit to operations had such unrealized amounts been realized. DAC for investment and universal life insurance products is subject to recoverability testing in the year of policy issuance, and DAC for universal life insurance products is also subject to loss recognition testing at the end of each reporting period.
	The Company regularly evaluates and adjusts the DAC balance when actual gross profits in a given reporting period vary from management’s initial estimates. Additionally, the assumptions used in the estimation of gross profits are based on the Company’s current best estimates of future events and are reviewed as part of an annual process. During the annual process, the Company performs a comprehensive study of assumptions, including mortality and persistency studies, maintenance expense studies and an evaluation of projected general and separate account investment returns. The most significant assumptions that are involved in the estimation of future gross profits include future net separate account investment performance, surrender/lapse rates, interest margins, renewal premiums and mortality. The Company refers to this process as “unlocking.” Quarterly, consideration is given as to whether adjustments to these assumptions are necessary. The Company uses a reversion to the mean process to determine the assumption for the future net separate account investment performance. This process assumes different performance levels over the next three years, such that the separate account mean return, measured from the anchor date to the end of the life of the product, equals the long-term assumption. The Company’s long-term assumptions for net separate account investment performance consist of assumed gross returns of 10.5% for equity funds and 5.0% for fixed funds.
	Changes in assumptions and the emergence of actual gross profits can have a significant impact on the amount of DAC reported for investment and universal life insurance products and their related amortization patterns. Additionally, the amortization of DAC can be affected by the change in the valuation of the Company’s variable annuity guarantees. See Future Policy Benefits and Claims for further discussion of the valuation of the Company’s variable annuity guarantees. In the event actual experience differs from assumptions or future assumptions are revised, the Company will record an increase or decrease in DAC amortization expense, which could be significant.
	Traditional life insurance. DAC is amortized with interest over the premium-paying period of the related policies in proportion to premium revenue recognized. These assumptions are consistent with those used in the calculation of liabilities for future policy benefits at issuance. DAC is evaluated for recoverability at the time of policy issuance, and loss recognition testing is conducted each reporting period.
	Refer to Note 5 for discussion regarding assumption changes impacting DAC amortization and related balances.
Investments	Investments
	Available-for-sale securities. Available-for-sale securities are reported at fair value, with unrealized holding gains and losses reported as a separate component of other comprehensive income, net of adjustments for DAC and other expenses, future policy benefits and claims, policyholder dividend obligations and deferred federal income taxes. Realized gains and losses on sales of available-for-sale securities are recognized in income based on the specific identification method. Interest and dividend income is recognized when earned.
	As of December 31, 2014 and 2013, 99% of fixed maturity securities were priced using external source data. Independent pricing services are most often utilized (87% and 86% as of December 31, 2014 and 2013, respectively) to determine the fair value of securities for which market quotations are available. For these securities, the Company obtains the pricing services’ methodologies, inputs and assumptions and classifies the investments accordingly in the fair value hierarchy.
	A corporate pricing matrix is used in valuing certain corporate debt securities. The corporate pricing matrix is developed using private spreads for corporate securities with varying weighted average lives and credit quality ratings. The weighted average life and credit quality rating of a particular fixed maturity security to be priced using the corporate pricing matrix are important inputs into the model and are used to determine a corresponding spread that is added to the appropriate U.S. Treasury yield to create an estimated market yield for that security. The estimated market yield and other relevant factors are then used to estimate the fair value of the particular security.
	Non-binding broker quotes are also utilized to determine the fair value of certain corporate debt, mortgage-backed and other asset-backed securities when quotes are not available from independent pricing services, corporate pricing matrix or internal pricing models. These securities are classified with the lowest priority in the fair value hierarchy as only one broker quote is ordinarily obtained, the investment is not traded on an exchange, the pricing is not available to other entities and/or the transaction volume in the same or similar investments has decreased. Inputs used in the development of prices are not provided to the Company by the brokers, as the brokers often do not provide the necessary transparency into their quotes and methodologies. At least annually, the Company performs reviews and tests to ensure that quotes are a reasonable estimate of the investments’ fair value. Price movements of broker quotes are subject to validation and require approval from the Company’s management. Management uses its knowledge of the investment and current market conditions to determine if the price is indicative of the investment’s fair value.
	When the collectability of contractual interest payments on fixed maturity securities is considered doubtful, such securities are placed in non-accrual status and any accrued interest is excluded from investment income. These securities are not restored to accrual status until the Company determines that payment of future principal and interest is probable.
	For investments in certain residential and commercial mortgage-backed securities, the Company recognizes income and amortizes discounts and premiums using the effective-yield method, based on prepayment assumptions and the estimated economic life of the securities. When actual prepayments differ significantly from estimated prepayments, the effective-yield is recalculated to reflect actual payments to date and anticipated future payments. Any resulting adjustment is included in net investment income in the period the estimates are revised. All other investment income is recorded using the effective-yield method without anticipating the impact of prepayments.
	The Company periodically reviews its available-for-sale securities to determine if any decline in fair value to below amortized cost is other-than-temporary. Factors considered in determining whether a decline is other-than-temporary include the length of time a security has been in an unrealized loss position, the severity of the unrealized loss, reasons for the decline in value and expectations for the amount and timing of a recovery in fair value.
	In assessing corporate debt securities for other-than-temporary impairment, the Company evaluates the ability of the issuer to meet its debt obligations, the value of the company or specific collateral securing the debt, the Company’s intent to sell the security and whether it is more likely than not the Company will be required to sell the security before the recovery of its amortized cost basis. The Company evaluates U.S. government and agencies, as well as obligations of states, political subdivisions and foreign governments for other-than-temporary impairment by examining similar characteristics.
	When evaluating whether residential mortgage-backed securities, commercial mortgage-backed securities and other asset-backed securities are other-than-temporarily impaired, the Company examines characteristics of the underlying collateral, such as delinquency and default rates, the quality of the underlying borrower, the type of collateral in the pool, the vintage year of the collateral, subordination levels within the structure of the collateral pool, the quality of any credit guarantors, the Company’s intent to sell the security and whether it is more likely than not it will be required to sell the security before the recovery of its amortized cost basis.
	The Company evaluates its intent to sell on an individual security basis. Other-than-temporary impairment losses on securities when the Company does not intend to sell the security and it is not more likely than not it will be required to sell the security prior to recovery of the security’s amortized cost basis are bifurcated, with the credit portion of the impairment loss being recognized in earnings and the non-credit loss portion of the impairment and any subsequent changes in the fair value of those debt securities being recognized in other comprehensive income, net of applicable taxes and other offsets. To estimate the credit portion of an impairment loss recognized in earnings, the Company considers the present value of the cash flows. To the extent that the present value of cash flows generated by a debt security is less than the amortized cost, an other-than-temporary impairment is recognized through earnings.
	It is possible that further declines in fair values of such investments, or changes in assumptions or estimates of anticipated recoveries and/or cash flows, may cause further other-than-temporary impairments in the near term, which could be significant.
	Mortgage loans, net of allowance. The Company holds commercial mortgage loans that are collateralized by properties throughout the U.S. These mortgage loans are further segregated into the following classes based on the unique risk profiles of the underlying property types: office, industrial, retail, apartment and other. Mortgage loans held-for-investment are held at amortized cost less a valuation allowance.
	As part of the underwriting process, specific guidelines are followed to ensure the initial quality of a new mortgage loan. Third-party appraisals are generally obtained to support loaned amounts, as the loans are usually collateral dependent.
	The collectability and value of a mortgage loan are based on the ability of the borrower to repay and/or the value of the underlying collateral. Many of the Company’s commercial mortgage loans are structured with balloon payment maturities, exposing the Company to risks associated with the borrowers’ ability to make the balloon payment or refinance the property.
	The Company actively monitors the credit quality of its mortgage loans to support the development of the valuation allowance. This monitoring process includes quantitative analyses, which facilitate the identification of deteriorating loans, and qualitative analyses, which consider other factors relevant to the borrowers’ ability to repay. Surveillance procedures identify loans with deteriorating credit fundamentals and these loans are evaluated based on the severity of their deterioration and management’s judgment as to the likelihood of loss.
	Mortgage loans require a loan-specific reserve when, based on current information and events, it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. When management determines that a loan requires a loan-specific reserve, a provision for loss is established equal to the difference between the carrying value and either the fair value of the collateral less costs to sell or the present value of expected future cash flows discounted at the loan’s market interest rate. Loan-specific reserve charges are recorded in net realized investment gains and losses. In the event a loan-specific reserve charge is reversed, the recovery is also recorded in net realized investment gains and losses.
	In addition to the loan-specific reserves, the Company maintains a non-specific reserve based primarily on loan surveillance categories and property type classes, which reflects management’s best estimate of probable credit losses inherent in the portfolio of loans without specific reserves as of the balance sheet date. Management’s periodic evaluation of the adequacy of the non-specific reserve is based on past loan loss experience, known and inherent risks in the portfolio, adverse situations that may affect a borrower’s ability to repay, the estimated value of the underlying collateral, composition of the loan portfolio, current economic conditions and other relevant factors. Non-specific reserve changes are recorded in net realized investment gains and losses.
	Interest income on performing mortgage loans is recognized over the life of the loan using the effective-yield method. Loans in default or in the process of foreclosure are placed on non-accrual status. Interest received on non-accrual status mortgage loans is included in net investment income in the period received. Loans are considered delinquent when contractual payments are 90 days past due.
	Policy loans. Policy loans, which are collateralized by the related insurance policy, are held at the outstanding principal balance and do not exceed the net cash surrender value of the policy. As such, no valuation allowance for policy loans is required.
	Short-term investments. Short-term investments consist primarily of highly liquid mutual funds and government agency discount notes with maturities of twelve months or less at acquisition. The Company and various affiliates maintain agreements with Nationwide Cash Management Company (“NCMC”), an affiliate, under which NCMC acts as a common agent in handling the purchase and sale of short-term securities for the respective accounts of the participants. Amounts on deposit with NCMC for the benefit of the Company are included in short-term investments on the consolidated balance sheets. The Company carries short-term investments at fair value.
	Other investments. Other investments consist primarily of equity method investments in private equity, hedge funds and partnerships, as well as COLI, trading securities, equity securities and capital stock with the FHLB.
	Securities lending. The Company has entered into securities lending agreements with a custodial bank whereby eligible securities are loaned to third parties, primarily major brokerage firms. These transactions are used to generate additional income on the securities portfolio. The Company is entitled to receive from the borrower any payments of interest and dividends received on loaned securities during the loan term. The agreements require a minimum of 102% of the fair value of loaned securities to be held as collateral. Cash collateral is invested by the custodial bank in investment-grade securities, which are included in the total investments of the Company. Periodically, the Company may receive non-cash collateral, which would be recorded off-balance sheet. The Company recognizes loaned securities in either available-for-sale or other investments. A securities lending payable is recorded in other liabilities for the amount of cash collateral received. Net income received from securities lending activities is included in net investment income. As of December 31, 2014 and 2013, the fair value of loaned securities was $254 million and $116 million, respectively.
	Variable interest entities. In the normal course of business, the Company has relationships with VIEs. If the Company determines that it has a variable interest and is the primary beneficiary, it consolidates the VIE. The Company is the primary beneficiary if the Company has the power to direct the activities of the VIE that most significantly impact the economic performance of the entity and the obligation to absorb losses or receive benefits from the entity that could be potentially significant to the VIE. This determination is based on a review of the entity’s contract and other deal related information, such as the entity’s equity investment at risk, decision-making abilities, obligations to absorb economic risks and right to receive economic rewards of the entity.
	The majority of the VIEs consolidated by the Company are due to guarantees provided to limited partners related to the amount of tax credits that will be generated by Low-Income-Housing Tax Credit Funds (“Tax Credit Funds”). The results of operations and financial position of each VIE for which the Company is the primary beneficiary, as well as the corresponding noncontrolling interests, are recorded in the consolidated financial statements. Ownership interests held by unrelated third parties in the consolidated VIEs are presented as noncontrolling interests in the equity section of the consolidated financial statements. Losses attributable to noncontrolling interests are excluded from the net income attributable to NLIC on the consolidated statements of operations.
	The Company invests in fixed maturity securities that could qualify as VIEs, including corporate securities, mortgage-backed securities and asset-backed securities. The Company is not the primary beneficiary of these securities as the Company does not have the power to direct the activities that most significantly impact the entities’ performance. The Company’s maximum exposure to loss is limited to the carrying values of these securities. There are no liquidity arrangements, guarantees or other commitments by third parties that affect the fair value of the Company’s interest in these assets. Refer to Note 6 for additional disclosures related to these investments.
	The Company is not required and does not intend to provide financial or other support outside of contractual requirements to any VIE.
Derivative Instruments	Derivative Instruments
	The Company uses derivative instruments to manage exposures and mitigate risks primarily associated with interest rates, equity markets and foreign currency. These derivative instruments primarily include interest rate swaps, futures contracts and options. Certain features embedded in the Company’s indexed products and certain variable annuity contracts require derivative accounting. Refer to the prior discussion of Future Policy Benefits and Claims for a description of the valuation applicable to these products. All derivative instruments are held at fair value and are reflected as assets or liabilities in the consolidated balance sheets.
	The fair value of derivative instruments is determined using various valuation techniques relying predominantly on observable market inputs. These inputs include interest rate swap curves, credit spreads, interest rates, counterparty credit risk, equity volatility and equity index levels. In cases where observable inputs are not available, the Company will utilize non-binding broker quotes to determine fair value, and these instruments are classified accordingly in the fair value hierarchy. Price movements of these broker quotes are subject to validation and require approval from the Company’s management. Management uses models to internally value the instruments for comparison to the values received through broker quotes.
	For derivatives that are not designated for hedge accounting, the gain or loss on the derivative is primarily recognized in net realized investment gains and losses.
	For derivative instruments that are designated and qualify for fair value hedge accounting, the gain or loss on the derivative instrument, as well as the hedged item to the extent of the risk being hedged, are recognized in net realized investment gains and losses.
	For derivative instruments that are designated and qualify for cash flow hedge accounting, the effective portion of the gain or loss on the derivative instrument is reported as a component of AOCI and reclassified into earnings in the same period or periods that the hedged transaction impacts earnings. The ineffective portion of the derivative’s change in value, if any, along with any of the derivative’s change in value that is excluded from the assessment of hedge effectiveness, are recorded in net realized investment gains and losses.
	The Company’s derivative transaction counterparties are generally financial institutions. To reduce the credit risk associated with open contracts, the Company enters into master netting agreements, which permit the closeout and netting of transactions with the same counterparty upon the occurrence of certain events. In addition, the Company attempts to reduce credit risk by obtaining collateral from counterparties. The determination of the need for and the levels of collateral vary based on an assessment of the credit risk of the counterparty. The Company accepts collateral in the form of cash and marketable securities.
Fair Value Measurements	Fair Value Measurements
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements are based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s view of market assumptions in the absence of observable market information. The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. In determining fair value, the Company uses various methods, including market and income approaches.
	The Company categorizes its financial instruments into a three-level hierarchy based on the priority of the inputs to the valuation technique. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). If the inputs used to measure fair value fall within different levels of the hierarchy, the category level is based on the lowest priority level input that is significant to the fair value measurement of the instrument in its entirety.
	The Company categorizes assets and liabilities held at fair value in the consolidated balance sheets as follows:
	Level 1. Unadjusted quoted prices accessible in active markets for identical assets or liabilities at the measurement date and mutual funds where the value per share (unit) is determined and published daily and is the basis for current transactions.
	Level 2. Unadjusted quoted prices for similar assets or liabilities in active markets or inputs (other than quoted prices) that are observable or that are derived principally from or corroborated by observable market data through correlation or other means. Primary inputs to this valuation technique may include comparative trades, bid/asks, interest rate movements, U.S. Treasury rates, London Interbank Offered Rate (“LIBOR”), prime rates, cash flows, maturity dates, call ability, estimated prepayments, and/or underlying collateral values.
	Level 3. Prices or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement. Inputs reflect management’s best estimate about the assumptions market participants would use at the measurement date in pricing the asset or liability. Consideration is given to the risk inherent in both the method of valuation and the valuation inputs.
	The Company reviews its fair value hierarchy classifications for assets and liabilities quarterly. Changes in the observability of significant valuation inputs identified during these reviews may trigger reclassifications. Reclassifications are reported as transfers at the beginning of the period in which the change occurs.
Fair Value Option	Fair Value Option
	The Company assesses the fair value option election for newly acquired assets or liabilities on a prospective basis. There are no material assets or liabilities for which the Company has elected the fair value option.
Federal Income Taxes	Federal Income Taxes
	The Company recognizes deferred tax assets and liabilities for the expected future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, net operating losses and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income or loss in the years in which those temporary differences are expected to be recovered or settled. Under this method, the effect on deferred tax assets and liabilities due to a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are recorded to reduce a deferred tax asset to the amount expected to be realized. Interest expense and any associated penalties which relate to tax years still subject to review by the Internal Revenue Service (“IRS”) are recorded as income tax expense.
	The Company provides for federal income taxes based on amounts the Company believes it ultimately will owe. Inherent in the provision for federal income taxes are estimates regarding the deductibility of certain items and the realization of certain tax credits. In the event the ultimate deductibility of certain items or the realization of certain tax credits differs from estimates, the Company may be required to change the provision for federal income taxes recorded in the consolidated financial statements, which could be significant.
	Tax reserves are reviewed regularly and are adjusted as events occur that the Company believes impact its liability for additional taxes, such as the lapsing of applicable statutes of limitations, conclusion of tax audits or substantial agreement with taxing authorities on the deductibility/nondeductibility of uncertain items, additional exposure based on current calculations, identification of new issues, release of administrative guidance or rendering of a court decision affecting a particular tax issue.
	NLIC files a separate consolidated federal income tax return with its subsidiaries and is eligible to join the NMIC consolidated tax return group in 2015.
Cash and Cash Equivalents	Cash and Cash Equivalents
	Cash and cash equivalents include highly liquid investments with original maturities of less than three months.
Goodwill	Goodwill
	In connection with business acquisitions, the Company recognizes goodwill as the excess of the purchase price over the fair value of net assets acquired as goodwill. Goodwill is not amortized, but is evaluated for impairment at the reporting unit level annually. Goodwill of a reporting unit is tested for impairment on an interim basis, in addition to the annual evaluation, if an event occurs or circumstances change which would more likely than not reduce the fair value of a reporting unit below its carrying amount. If a reporting unit’s fair value is less than its carrying value, the Company will calculate implied goodwill. An impairment would be recognized on a reporting unit for the amount that the carrying value of its goodwill exceeds the implied value of its goodwill.
	The process of evaluating goodwill for impairment requires several judgments and assumptions to be made to determine the fair value of the reporting units, including the method used to determine fair value, discount rates, expected levels of cash flows, revenues and earnings, and the selection of comparable companies used to develop market-based assumptions. The Company performed its 2014 annual impairment test and determined that no impairment was required.
Closed Block	Closed Block
	In connection with the sponsored demutualization of Provident Mutual Life Insurance Company (“Provident”) prior to its acquisition by the Company, Provident established a closed block for the benefit of certain classes of individual participating policies that had a dividend scale payable in 2001. Assets were allocated to the closed block in an amount that produces cash flows which, together with anticipated revenues from closed block business, is reasonably expected to be sufficient to provide for (1) payment of policy benefits, specified expenses and taxes, and (2) the continuation of dividends throughout the life of the Provident policies included in the closed block based upon the dividend scales payable for 2001, if the experience underlying such dividend scales continues.
	Assets allocated to the closed block benefit only the holders of the policies included in the closed block and will not revert to the benefit of the Company. No reallocation, transfer, borrowing or lending of assets can be made between the closed block and other portions of the Company’s general account, any of its separate accounts, or any affiliate of the Company without the approval of the Pennsylvania Insurance Department and Ohio Department of Insurance (“ODI”). The closed block will remain in effect as long as any policy in the closed block is in force.
	If, over time, the aggregate performance of the closed block assets and policies is better than was assumed in funding the closed block, dividends to policyholders will increase. If, over time, the aggregate performance of the closed block assets and policies is less favorable than was assumed in the funding, dividends to policyholders could be reduced. If the closed block has insufficient funds to make guaranteed policy benefit payments, such payments will be made from the Company’s assets outside of the closed block, which are general account assets.
	The assets and liabilities allocated to the closed block are recorded in the Company’s consolidated financial statements on the same basis as other similar assets and liabilities. The carrying amount of closed block liabilities in excess of the carrying amount of closed block assets at the date Provident was acquired by the Company represents the maximum future earnings from the assets and liabilities designated to the closed block that can be recognized in income, for the benefit of stockholders, over the period the policies in the closed block remain in force.
	If actual cumulative earnings exceed expected cumulative earnings, the expected earnings are recognized in income. This is because the excess actual cumulative earnings over expected cumulative earnings, which represents undistributed accumulated earnings attributable to policyholders, is recorded as a policyholder dividend obligation. Therefore, the excess will be paid to closed block policyholders as an additional policyholder dividend expense in the future unless it is otherwise offset by future performance of the closed block that is less favorable than originally expected. If actual cumulative performance is less favorable than expected, actual earnings will be recognized in income.
	The principal cash flow items that affect the amount of closed block assets and liabilities are premiums, net investment income, purchases and sales of investments, policyholder benefits, policyholder dividends, premium taxes and income taxes. The principal income and expense items excluded from the closed block are management and maintenance expenses, commissions and net investment income and realized gains and losses on investments held outside of the closed block that support the closed block business, all of which enter into the determination of total gross margins of closed block policies. See Note 10 for further disclosure.
Separate Accounts	Separate Accounts
	Separate account assets and liabilities represent contractholders’ funds that have been legally segregated into accounts with specific investment objectives. In the separate account, investment income and gains and losses on investments accrue directly to, and investment risk is borne by, the contractholder. Separate account assets are primarily comprised of public, privately registered and non-registered mutual funds. Separate account assets are recorded at fair value based on the methodology that would be applicable to the underlying assets. The value of separate account liabilities is set to equal the fair value for separate account assets.
Participating Business	Participating Business
	Participating business, which refers to policies that participate in profits through policyholder dividends, represented approximately 4% of the Company’s life insurance in force in 2014 and 2013 and 5% in 2012 and 37% of the number of life insurance policies in force in 2014 (38% in 2013 and 40% in 2012). The provision for policyholder dividends was based on the respective year’s dividend scales and has been included in future policy benefits and claims in the consolidated balance sheets.
Subsequent Events	Subsequent Events
	The Company evaluated subsequent events through February 25, 2015, the date the consolidated financial statements were issued.

Certain_LongDuration_Contracts1

Certain Long-Duration Contracts (Tables)	12 Months Ended
	Dec. 31, 2014
Summarizes information regarding variable annuity contracts with guarantees invested in general and separate accounts	The following table summarizes information regarding variable annuity contracts with guarantees invested in general and separate accounts, as of the dates indicated (a contract may contain multiple guarantees):
			December 31, 2014									December 31, 2013
	(in millions)		General		Separate			Net		Average		General		Separate		Net		Average
			account		account			amount		age2		account		account		amount		age2
			value		value			at risk1				value		value		at risk1
	Contracts with GMDB:
	Return of net deposits		$	872	$	23,079		$	21		65	$	916	$	19,927	$	13		64
	Minimum return or anniversary contract value			1,918		33,662			292		69		2,031		33,520		237		69
	Total contracts with GMDB		$	2,790	$	56,741		$	313		68	$	2,947	$	53,447	$	250		67
	GLWB Minimum return or anniversary contract value		$	135	$	31,031		$	195		66	$	178	$	28,071	$	74		64
	GMAB Return of net deposits3		$	43	$	1,552		$	—		67	$	92	$	2,383	$	—		64
	GMIB Minimum return or anniversary contract value		$	45	$	451		$	1		66	$	49	$	510	$	—		64
	1	Net amount at risk is calculated on a policy-level basis and equals the respective guaranteed benefit less the account value (or zero if the account value exceeds the guaranteed benefit).
	2	Represents the weighted average attained age of contractholders.
	3	Contracts with the hybrid accumulation/withdrawal benefits are included with the accumulation benefits contracts.
Summarizes the reserve balances, for variable annuity contracts with guarantees	The following table summarizes the reserve balances for guarantees on variable annuity contracts, as of the dates indicated:
			December 31,
	(in millions)		2014		2013
	GMDB		$	76	$	55
	GLWB1		$	174	$	(1,075	)
	GMAB1, 2		$	3	$	(19	)
	GMIB		$	1	$	2
	1	The changes in reserve balances for withdrawal benefits and accumulation benefits were primarily driven by declines in key interest rates, partially offset by rising equity markets during 2014. Refer to Note 7 for discussion of the related derivative programs.
	2	Contracts with the hybrid accumulation/withdrawal benefits are included with the accumulation benefits contracts.
Summarizes account balances of deferred variable annuity	The following table summarizes the account balances of deferred variable annuity contracts with guarantees invested in separate accounts, as of the dates indicated:
			December 31,
	(in millions)		2014		2013
	Mutual funds:
	Bond		$	5,280	$	5,685
	Domestic equity			47,316		43,505
	International equity			2,969		3,179
	Total mutual funds		$	55,565	$	52,369
	Money market funds			1,176		1,078
	Total1		$	56,741	$	53,447
	1	Excludes $31.3 billion and $30.6 billion as of December 31, 2014 and 2013, respectively, of separate account assets not related to deferred variable annuity contracts with guarantees, primarily attributable to retirement plan, variable universal life and COLI products.
Summarizes information regarding universal and variable universal life insurance contracts with no lapse guarantees invested in general and separate accounts	The following table summarizes information regarding universal and variable universal life insurance contracts with no-lapse guarantees invested in general and separate accounts, as of the dates indicated:
	(in millions)		General account		Separate account			Adjusted insurance		Average age2
			value		value			in force1
	December 31, 2014		$	1,954	$	2,191		$	41,484		51
	December 31, 20133		$	1,522	$	2,235		$	36,956		51
	1	The adjusted insurance in force is calculated on a policy-level basis and equals the respective guaranteed death benefit less the account value.
	2	Represents the weighted average attained age of contractholders.
	3	Amounts above are based on all policies with no-lapse guarantees. Previously, only those policies with a no-lapse guarantee carrying a reserve were included in the disclosure.

Deferred_Policy_Acquisition_Co1

Deferred Policy Acquisition Costs (Tables)	12 Months Ended
	Dec. 31, 2014
Deferred policy acquisition costs	The following table summarizes changes in the DAC balance, as of the dates indicated:
		December 31,
	(in millions)	2014			2013			2012
	Balance at beginning of year	$	3,778		$	3,249		$	3,487
	Capitalization of DAC		685			604			470
	Amortization of DAC, excluding unlocks		(397	)		(373	)		(525	)
	Amortization of DAC related to unlocks		190			(1	)		(50	)
	Adjustments to DAC related to unrealized gains and losses on available-for-sale securities		(193	)		299			(133	)
	Balance at end of year	$	4,063		$	3,778		$	3,249

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Available-for-Sale Securities	The following table summarizes the amortized cost, unrealized gains and losses and fair value of available-for-sale securities, as of the dates indicated:
	(in millions)		Amortized			Unrealized			Unrealized			Fair value
			cost			gains			losses
	December 31, 2014
	Fixed maturity securities:
	U.S. government and agencies		$	448		$	79		$	—		$	527
	Obligations of states, political subdivisions and foreign governments			1,966			320			1			2,285
	Corporate public securities			19,851			1,519			120			21,250
	Corporate private securities			4,398			286			34			4,650
	Residential mortgage-backed securities			3,694			190			45			3,839
	Commercial mortgage-backed securities			1,431			74			3			1,502
	Other asset-backed securities			1,410			27			72			1,365
	Total fixed maturity securities		$	33,198		$	2,495		$	275		$	35,418
	Equity securities			6			15			—			21
	Total available-for-sale securities		$	33,204		$	2,510		$	275		$	35,439
	December 31, 2013
	Fixed maturity securities:
	U.S. government and agencies		$	484		$	79		$	2		$	561
	Obligations of states, political subdivisions and foreign governments			1,892			111			40			1,963
	Corporate public securities			18,004			1,076			295			18,785
	Corporate private securities			4,374			258			38			4,594
	Residential mortgage-backed securities			3,919			163			79			4,003
	Commercial mortgage-backed securities			1,439			86			21			1,504
	Other asset-backed securities			890			26			77			839
	Total fixed maturity securities		$	31,002		$	1,799		$	552		$	32,249
	Equity securities			6			18			—			24
	Total available-for-sale securities		$	31,008		$	1,817		$	552		$	32,273
Summarizes the amortized cost and fair value of fixed maturity securities	Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without early redemption penalties.
	(in millions)		Amortized			Fair
			cost			value
	Fixed maturity securities:
	Due in one year or less		$	1,018		$	1,037
	Due after one year through five years			9,196			9,898
	Due after five years through ten years			8,267			8,617
	Due after ten years			8,182			9,160
	Subtotal		$	26,663		$	28,712
	Residential mortgage-backed securities			3,694			3,839
	Commercial mortgage-backed securities			1,431			1,502
	Other asset-backed securities			1,410			1,365
	Total fixed maturity securities		$	33,198		$	35,418
Summarizes components of net unrealized gains and losses on available-for-sale securities	The following table summarizes components of net unrealized gains and losses, as of the dates indicated:
			December 31,
	(in millions)		2014			2013
	Net unrealized gains on available-for-sale securities, before adjustments, taxes and fair value hedging		$	2,235		$	1,265
	Net unrealized gains on available-for-sale securities, before adjustments and taxes1		$	2,235		$	1,265
	Adjustment to DAC and other expense			(372	)		(176	)
	Adjustment to future policy benefits and claims			(159	)		(89	)
	Adjustment to policyholder dividend obligation			(120	)		(85	)
	Deferred federal income tax expense			(548	)		(314	)
	Net unrealized gains on available-for-sale securities		$	1,036		$	601
	1	Includes net unrealized losses of $9 million and $40 million as of December 31, 2014 and 2013, respectively, related to the non-credit portion of other-than-temporarily impaired securities.
Summarizes change in net unrealized gains and losses on available for sale securities	The following table summarizes the change in net unrealized gains and losses reported in accumulated other comprehensive income, for the years ended:
			December 31,
	(in millions)		2014			2013
	Balance at beginning of year		$	601		$	1,264
	Unrealized gains and losses arising during the year:
	Net unrealized gains (losses) on available-for-sale securities before adjustments			939			(1,657	)
	Non-credit impairments and subsequent changes in fair value of impaired debt securities			31			8
	Net adjustment to DAC and other expense			(196	)		306
	Net adjustment to future policy benefits and claims			(70	)		206
	Net adjustment to policyholder dividend obligations			(35	)		92
	Related federal income tax (expense) benefit			(234	)		366
	Unrealized gains (losses) on available-for-sale securities		$	435		$	(679	)
	Reclassification adjustment for net losses realized on available-for-sale securities, net of tax benefit ($0 and $8 as of December 31, 2014 and 2013, respectively)			—			(16	)
	Net unrealized gains (losses) on available-for-sale securities		$	435		$	(663	)
	Balance at end of year		$	1,036		$	601
Summarizes available for sale securities by asset class in gross unrealized loss position	The following table summarizes, by asset class, available-for-sale securities, in an unrealized loss position based on the amount of time each type of security has been in an unrealized loss position, as well as the related fair value, as of the dates indicated:
			Less than or equal to one year						More than one year					Total
	(in millions)		Fair			Unrealized			Fair			Unrealized		Unrealized
			value			losses			value			losses		losses1
	December 31, 2014
	Fixed maturity securities:
	Corporate public securities		$	1,642		$	63		$	1,578		$	57	$	120
	Residential mortgage-backed securities			268			2			487			43		45
	Other asset-backed securities			662			5			493			67		72
	Other			589			27			457			11		38
	Total2		$	3,161		$	97		$	3,015		$	178	$	275
	December 31, 2013
	Fixed maturity securities:
	Corporate public securities		$	4,889		$	256		$	442		$	39	$	295
	Residential mortgage-backed securities			725			16			604			63		79
	Other asset-backed securities			507			6			144			71		77
	Other			1,838			85			222			16		101
	Total2		$	7,959		$	363		$	1,412		$	189	$	552
	1	As of December 31, 2014 and 2013, there were $66 million and $82 million, respectively, of unrealized losses related to available-for-sale securities with a fair value to amortized cost ratio of less than 80%.
	2	Represents 541 and 816 available-for-sale securities in an unrealized loss position as of December 31, 2014 and 2013, respectively.
Summary of the amortized cost of mortgage loans	The following table summarizes the amortized cost of mortgage loans by method of evaluation for credit loss, and the related valuation allowances by type of credit loss, as of the dates indicated:
			December 31,
	(in millions)		2014			2013
	Amortized cost:
	Loans with non-specific reserves		$	7,279		$	6,350
	Loans with specific reserves			17			26
	Total amortized cost		$	7,296		$	6,376
	Valuation allowance:
	Non-specific reserves		$	21		$	29
	Specific reserves			5			6
	Total valuation allowance		$	26		$	35
	Mortgage loans, net of allowance		$	7,270		$	6,341
Activity in the valuation allowance for mortgage loans	The following table summarizes activity in the valuation allowance for mortgage loans, for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Balance at beginning of year		$	35		$	44		$	60
	Current period provision1			(8	)		(4	)		2
	Recoveries2			(1	)		(5	)		(15	)
	Charge offs and other			—			—			(3	)
	Balance at end of year		$	26		$	35		$	44
	1	Includes specific reserve provisions and all changes in non-specific reserves.
	2	Includes recoveries on sales and increases in the valuation of loans with specific reserves.
Summary of LTV ratio and DSC ratios of the mortgage loan portfolio	The following table summarizes the LTV ratio and DSC ratios of the mortgage loan portfolio, as of the dates indicated:
			LTV ratio											DSC ratio
	(in millions)		Less			80% -			90% or			Total		Greater		1.00-		Less		Total
			than			less			greater					than		1.1		than
			80%			than								1.1				1
						90%
	31-Dec-14
	Apartment		$	2,156		$	111		$	17		$	2,284	$	2,252	$	26	$	6	$	2,284
	Industrial			1,131			34			35			1,200		1,048		89		63		1,200
	Office			1,004			16			20			1,040		990		4		46		1,040
	Retail			2,506			64			11			2,581		2,421		128		32		2,581
	Other			191			—			—			191		191		—		—		191
	Total1		$	6,988		$	225		$	83		$	7,296	$	6,902	$	247	$	147	$	7,296
	31-Dec-13
	Apartment		$	1,788		$	52		$	30		$	1,870	$	1,857	$	6	$	7	$	1,870
	Industrial			951			52			86			1,089		893		122		74		1,089
	Office			837			30			38			905		800		43		62		905
	Retail			2,236			41			21			2,298		2,214		61		23		2,298
	Other			213			—			1			214		214		—		—		214
	Total2		$	6,025		$	175		$	176		$	6,376	$	5,978	$	232	$	166	$	6,376
	1	As of December 31, 2014, the weighted average DSC ratios for the respective LTV ratio ranges above were 1.97, 1.27 and 0.90, with a total weighted average DSC ratio of 1.93. As of December 31, 2014, the weighted average LTV ratios for the respective DSC ratio ranges above were 60%, 59% and 90%, with a total weighted average LTV ratio of 60%.
	2	As of December 31, 2013, the weighted average DSC ratios for the respective LTV ratio ranges above were 1.77, 1.22 and 1.00, with a total weighted average DSC ratio of 1.74. As of December 31, 2013, the weighted average LTV ratios for the respective DSC ratio ranges above were 60%, 61% and 91%, with a total weighted average LTV ratio of 61%.
Summary of net investment income by investment type	The following table summarizes net investment income, by investment type, for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Fixed maturity securities, available-for-sale		$	1,575		$	1,565		$	1,506
	Mortgage loans			362			348			366
	Policy loans			51			52			53
	Other			(29	)		(57	)		(45	)
	Gross investment income		$	1,959		$	1,908		$	1,880
	Investment expenses			59			59			55
	Net investment income		$	1,900		$	1,849		$	1,825
Net Realized Investment Gains and Losses	The following table summarizes net realized investment gains and losses, including other-than-temporary impairments, by source, for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Net realized derivative (losses) gains		$	(1,087	)	$	705		$	314
	Realized gains on sales			31			32			48
	Realized losses on sales			(19	)		(54	)		(23	)
	Other			2			—			12
	Net realized investment (losses) gains before other-than-temporary impairments on fixed maturity securities		$	(1,073	)	$	683		$	351
	Other-than-temporary impairments on fixed maturity securities1			(5	)		(5	)		(32	)
	Net realized investment (losses) gains, including other-than-temporary impairments		$	(1,078	)	$	678		$	319
	1	Other-than-temporary impairments on fixed maturity securities are net $1 million, $6 million and $36 million of non-credit losses included in other comprehensive income for the years ended December 31, 2014, 2013 and 2012, respectively.
Other-Than-Temporary Impairment Losses	The following table summarizes the cumulative credit losses, for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Cumulative credit losses at beginning of year1		$	(272	)	$	(289	)	$	(328	)
	New credit losses			(2	)		(3	)		(18	)
	Incremental credit losses			(4	)		(3	)		(10	)
	Losses related to securities included in the beginning balance sold or paid down during the period			24			23			67
	Cumulative credit losses at end of year1		$	(254	)	$	(272	)	$	(289	)
	1	Cumulative credit losses are defined as amounts related to the Company’s credit portion of the other-than-temporary impairment losses on debt securities that the Company does not intend to sell and that it is not more likely than not the Company will be required to sell prior to recovery of the amortized cost basis.

Derivative_Instruments_Tables

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of fair value of derivative instruments	The following table summarizes the fair value and related notional amounts of derivative instruments, as of the dates indicated:
			Derivative assets						Derivative liabilities
	(in millions)		Fair value			Notional			Fair value			Notional
	December 31, 2014
	Derivatives designated and qualifying as hedging instruments		$	29		$	381		$	9		$	176
	Derivatives not designated as hedging instruments:
	Interest rate contracts		$	2,602		$	32,829		$	2,611		$	32,756
	Equity contracts			411			5,990			—			—
	Total return swaps			—			—			41			2,808
	Other derivative contracts			—			—			3			2
	Total derivative instruments1		$	3,042		$	39,200		$	2,664		$	35,742
	Accrued interest on derivative assets and liabilities			243						244
	Total derivative positions		$	3,285					$	2,908
	December 31, 2013
	Derivatives designated and qualifying as hedging instruments		$	1		$	6		$	26		$	345
	Derivatives not designated as hedging instruments:
	Interest rate contracts		$	1,787		$	26,156		$	2,100		$	29,715
	Equity contracts			343			6,556			—			—
	Total return swaps			6			1,101			52			1,183
	Other derivative contracts			—			—			5			2
	Total derivative instruments1		$	2,137		$	33,819		$	2,183		$	31,245
	Accrued interest on derivative assets and liabilities			196						227
	Total derivative positions		$	2,333					$	2,410
	1	Derivative assets and liabilities are included in other assets and other liabilities, respectively, in the consolidated balance sheets.
Summary of realized gains and losses for derivative instruments	The following table summarizes gains and losses for derivative instruments recognized in net realized investment gains and losses in the consolidated statements of operations, for the years ended:
			December 31,
	(in millions)		2014			2013			2012
	Derivatives designated and qualifying as hedging instruments		$	—		$	(1	)	$	(1	)
	Derivatives not designated as hedging instruments:
	Interest rate contracts		$	142		$	(209	)	$	(125	)
	Equity contracts			(79	)		(776	)		(665	)
	Total return swaps			(195	)		(321	)		(343	)
	Other derivative contracts			4			(9	)		(1	)
	Net interest settlements			20			14			53
	Total derivative losses1		$	(108	)	$	(1,302	)	$	(1,082	)
	Change in embedded derivatives on guaranteed benefit annuity programs2			(1,271	)		1,751			1,185
	Other revenue on guaranteed benefit annuity programs			292			256			211
	Change in embedded derivative liabilities and related fees		$	(979	)	$	2,007		$	1,396
	Net realized derivative (losses) gains		$	(1,087	)	$	705		$	314
	1	Included in total derivative losses are economic hedging gains (losses) of $941 million, $(1.8) billion and $(827) million related to the guaranteed benefit annuity programs for the years ended December 31, 2014, 2013 and 2012, respectively. Also included are economic hedging (losses) gains of $(1.0) billion, $645 million and $(129) million, respectively, related to the program that protects against the negative impact of higher interest rates on the Company’s statutory surplus position.
	2	For the individual variable annuity business, the annual comprehensive review of model assumptions included a favorable impact for the years ended December 31, 2014 and 2013, primarily due to model enhancements and updated assumptions for discounting and benefit utilization, partially offset by mortality and lapse rates.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Assets and liabilities measured at fair value on a recurring basis	The following table summarizes assets and liabilities held at fair value on a recurring basis as of December 31, 2014:
	(in millions)		Level 1			Level 2			Level 3			Total
	Assets
	Investments:
	Fixed maturity securities, available-for-sale:
	U.S. government and agencies		$	523		$	1		$	3		$	527
	Obligations of states, political subdivisions and foreign governments			66			2,219			—			2,285
	Corporate public securities			—			21,158			92			21,250
	Corporate private securities			—			3,659			991			4,650
	Residential mortgage-backed securities			1,034			2,796			9			3,839
	Commercial mortgage-backed securities			—			1,499			3			1,502
	Other asset-backed securities			—			1,196			169			1,365
	Total fixed maturity securities, available-for-sale, at fair value		$	1,623		$	32,528		$	1,267		$	35,418
	Other investments at fair value1			42			899			36			977
	Investments at fair value		$	1,665		$	33,427		$	1,303		$	36,395
	Derivative instruments - assets			—			2,631			411			3,042
	Separate account assets			84,583			1,387			2,106			88,076
	Assets at fair value		$	86,248		$	37,445		$	3,820		$	127,513
	Liabilities
	Future policy benefits and claims:
	Embedded derivatives on living benefits		$	—		$	—		$	(177	)	$	(177	)
	Embedded derivatives on indexed products			—			—			(84	)		(84	)
	Total future policy benefits and claims		$	—		$	—		$	(261	)	$	(261	)
	Derivative instruments - liabilities			—			(2,661	)		(3	)		(2,664	)
	Liabilities at fair value		$	—		$	(2,661	)	$	(264	)	$	(2,925	)
	1	Other investments at fair value includes $21 million of trading securities as of December 31, 2014.
	The following table summarizes assets and liabilities held at fair value on a recurring basis as of December 31, 2013:
	(in millions)		Level 1			Level 2			Level 3			Total
	Assets
	Investments:
	Fixed maturity securities, available-for-sale:
	U.S. government and agencies		$	557		$	1		$	3		$	561
	Obligations of states, political subdivisions and foreign governments			63			1,900			—			1,963
	Corporate public securities			1			18,705			79			18,785
	Corporate private securities			—			3,791			803			4,594
	Residential mortgage-backed securities			791			3,203			9			4,003
	Commercial mortgage-backed securities			—			1,504			—			1,504
	Other asset-backed securities			—			645			194			839
	Total fixed maturity securities, available-for-sale, at fair value		$	1,412		$	29,749		$	1,088		$	32,249
	Other investments at fair value1			64			357			45			466
	Investments at fair value		$	1,476		$	30,106		$	1,133		$	32,715
	Derivative instruments - assets			—			1,794			343			2,137
	Separate account assets			80,647			1,339			2,083			84,069
	Assets at fair value		$	82,123		$	33,239		$	3,559		$	118,921
	Liabilities
	Future policy benefits and claims:
	Embedded derivatives on living benefits		$	—		$	—		$	1,094		$	1,094
	Embedded derivatives on indexed products			—			—			(84	)		(84	)
	Total future policy benefits and claims		$	—		$	—		$	1,010		$	1,010
	Derivative instruments - liabilities			—			(2,178	)		(5	)		(2,183	)
	Liabilities at fair value		$	—		$	(2,178	)	$	1,005		$	(1,173	)
	1	Other investments at fair value includes $31 million of trading securities as of December 31, 2013.
Fair value measurements of unobservable inputs	The following table presents the rollforward of Level 3 assets and liabilities held at fair value on a recurring basis during the year ended December 31, 2014:
	(in millions)		Fixed			Other			Derivative			Separate			Total assets			Liabilities at
			maturity			investments			assets3			account			at fair value			fair value3
			securities2									assets
	Balance as of December 31, 2013		$	1,088		$	45		$	343		$	2,083		$	3,559		$	1,005
	Net gains (losses)
	In operations1			(5	)		6			40			23			64			(1,269	)
	In other comprehensive income			21			1			—			—			22			—
	Purchases			121			—			46			—			167			—
	Sales			(241	)		(16	)		(18	)		—			(275	)		—
	Transfers into Level 3			400			—			—			—			400			—
	Transfers out of Level 3			(117	)		—			—			—			(117	)		—
	Balance as of December 31, 2014		$	1,267		$	36		$	411		$	2,106		$	3,820		$	(264	)
	1	Net gains and losses included in operations are reported in net realized investment gains and losses and interest credited to policyholder accounts. The net unrealized gains on separate account assets are attributable to contractholders and therefore are not included in the Company’s earnings. The change in unrealized (losses) gains included in operations on assets and liabilities still held at the end of the year was $(1.3) billion for future policy benefits and claims, $154 million for derivative assets, and $6 million for other investments at fair value.
	2	Non-binding broker quotes were utilized to determine a fair value of $1.1 billion of total fixed maturity securities as of December 31, 2014.
	3	Non-binding broker quotes were utilized to determine a fair value of all Level 3 derivative assets and liabilities.
	The following table presents the rollforward of Level 3 assets and liabilities held at fair value on a recurring basis during the year ended December 31, 2013:
	(in millions)		Fixed			Other			Derivative			Separate			Total assets			Liabilities at
			maturity			investments			assets3			account			at fair value			fair value3
			securities2									assets
	Balance as of December 31, 2012		$	1,197		$	62		$	822		$	2,025		$	4,106		$	(753	)
	Net gains (losses)
	In operations1			(1	)		(6	)		(447	)		58			(396	)		1,758
	In other comprehensive income			1			6			—			—			7			—
	Purchases			115			5			129			—			249			—
	Sales			(232	)		(22	)		(161	)		—			(415	)		—
	Transfers into Level 3			142			—			—			—			142			—
	Transfers out of Level 3			(134	)		—			—			—			(134	)		—
	Balance as of December 31, 2013		$	1,088		$	45		$	343		$	2,083		$	3,559		$	1,005
	1	Net gains and losses included in operations are reported in net realized investment gains and losses and interest credited to policyholder accounts. The net unrealized gains on separate account assets are attributable to contractholders and therefore are not included in the Company’s earnings. The change in unrealized gains (losses) included in operations on assets and liabilities still held as of the end of the year was $1.8 billion for future policy benefits and claims, $(297) million for derivative assets and $(6) million for other investments at fair value.
	2	Non-binding broker quotes were utilized to determine a fair value of $924 million of total fixed maturity securities as of December 31, 2013.
	3	Non-binding broker quotes were utilized to determine a fair value of all Level 3 derivative assets and liabilities.
Summary of significant unobservable inputs used for fair value measurements for living benefits liabilities	The following table summarizes significant unobservable inputs used for fair value measurements for living benefits liabilities classified as Level 3 as of December 31, 2014:
	Unobservable Inputs		Range
	Mortality		0.1% - 8%2
	Lapse		0% - 35%
	Wait period		0 yrs – 30 yrs3
	Efficiency of benefit utilization1		65% -100%
	Discount rate		See footnote 4
	Index volatility		15% - 25%
	1	The unobservable input is not applicable to GMABs.
	2	Represents the mortality for the majority of business with living benefits, with policyholders ranging from 45 to 85.
	3	A portion of the contractholders could never use the benefit, which would extend the range to an indeterminate period.
	4	Incorporates the liquidity and non-performance risk adjustment. The liquidity spread takes into consideration market observables for spreads in illiquid assets. The non-performance risk adjustment reflects an additional spread over LIBOR determined by market observables for similarly rated public bonds.
Summary of significant unobservable inputs used for fair value measurements for indexed universal life equity indexed products	The following table summarizes significant unobservable inputs used for fair value measurements for indexed universal life equity indexed products classified as Level 3 as of December 31, 2014:
	Unobservable Inputs		Range
	Mortality		0% - 4%1
	Lapse		0% - 10%
	Index volatility		15% - 25%
	1	Represents the mortality for the majority of business, with policyholders ranging from 0 to 75.
Summary of carrying value and fair value of the Company's financial instruments not carried at fair value	The following table summarizes the carrying value and fair value of the Company’s financial instruments not carried at fair value as of the dates indicated. The valuation techniques used to estimate these fair values are described below.
			December 31, 2014												December 31, 2013
	(in millions)		Carrying			Fair			Level 2			Level 3			Carrying			Fair			Level 2		Level 3
			value			value									value			value
	Assets
	Investments:
	Mortgage loans, net of allowance		$	7,270		$	7,616		$	—		$	7,616		$	6,341		$	6,481		$	—	$	6,481
	Policy loans		$	992		$	992		$	—		$	992		$	987		$	987		$	—	$	987
	Other investments		$	60		$	60		$	—		$	60		$	43		$	43		$	—	$	43
	Liabilities
	Investment contracts		$	23,470		$	21,742		$	—		$	21,742		$	21,874		$	20,436		$	—	$	20,436
	Short-term debt		$	660		$	660		$	—		$	660		$	278		$	278		$	—	$	278
	Long-term debt		$	709		$	1,069		$	1,060		$	9		$	707		$	1,004		$	997	$	7

Goodwill_Tables

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of changes in the carrying value of goodwill by segment	The following table summarizes changes in the carrying value of goodwill by segment for the years indicated:
	(in millions)		Retirement		Individual		Total
			Plans		Products &
					Solutions - Life
					and NBSG
	Balance as of December 31, 20121		$	25	$	175	$	200
	Adjustments			—		—		—
	Balance as of December 31, 20131		$	25	$	175	$	200
	Adjustments			—		—		—
	Balance as of December 31, 20141		$	25	$	175	$	200
	1	The goodwill balances have not been previously impaired.

Closed_Block_Tables

Closed Block (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of financial information for the closed block	The following table summarizes financial information for the closed block, as of the dates indicated:
		December 31,
	(in millions)	2014			2013
	Liabilities:
	Future policyholder benefits	$	1,669		$	1,703
	Policyholder funds and accumulated dividends		139			141
	Policyholder dividends payable		22			23
	Policyholder dividend obligation		152			113
	Other policy obligations and liabilities		33			29
	Total liabilities	$	2,015		$	2,009
	Assets:
	Fixed maturity securities, available-for-sale	$	1,336		$	1,320
	Mortgage loans, net of allowance		272			257
	Policy loans		149			157
	Other assets		86			93
	Total assets	$	1,843		$	1,827
	Excess of reported liabilities over assets		172			182
	Portion of above representing other comprehensive income:
	Increase (decrease) in unrealized gain on fixed maturity securities, available-for-sale	$	35		$	(92	)
	Adjustment to policyholder dividend obligation		(35	)		92
	Total	$	—		$	—
	Maximum future earnings to be recognized from assets and liabilities	$	172		$	182
	Other comprehensive income:
	Fixed maturity securities, available-for-sale:
	Fair value	$	1,336		$	1,320
	Amortized cost		1,216			1,235
	Shadow policyholder dividend obligation		(120	)		(85	)
	Net unrealized appreciation	$	—		$	—
Summary of closed block operations	The following table summarizes closed block operations for the years ended:
		December 31,
	(in millions)	2014			2013			2012
	Revenues:
	Premiums	$	61		$	66		$	73
	Net investment income		93			94			98
	Realized investment gains		1			—			1
	Realized losses credited to policyholder benefit obligation		(5	)		(4	)		(5	)
	Total revenues	$	150		$	156		$	167
	Benefits and expenses:
	Policy and contract benefits	$	124		$	123		$	134
	Change in future policyholder benefits and interest credited to policyholder accounts		(34	)		(29	)		(27	)
	Policyholder dividends		43			44			50
	Change in policyholder dividend obligation		(1	)		3			(8	)
	Other expenses		2			(2	)		1
	Total benefits and expenses	$	134		$	139		$	150
	Total revenues, net of benefits and expenses, before federal income tax expense	$	16		$	17		$	17
	Federal income tax expense		6			6			6
	Revenues, net of benefits and expenses and federal income tax expense	$	10		$	11		$	11
	Maximum future earnings from assets and liabilities:
	Beginning of period	$	182		$	193		$	204
	Change during period		(10	)		(11	)		(11	)
	End of period	$	172		$	182		$	193

ShortTerm_Debt_Tables

Short-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of short-term debt and weighted average annual interest rates	The following table summarizes the carrying value of short-term debt and weighted average annual interest rates, as of the dates indicated:
		December 31,
	(in millions)	2014		2013
	$600 million commercial paper program (0.20% and 0.24%, respectively)	$	264	$	278
	$400 million revolving variable rate line of credit (1.57% and 0.00%, respectively)		396		—
	Total short-term debt	$	660	$	278

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of long-term debt	The following table summarizes the carrying value of long-term debt, as of the dates indicated:
		December 31,
	(in millions)	2014		2013
	8.15% surplus note, due June 26, 2032, payable to NFS	$	300	$	300
	7.50% surplus note, due December 17, 2031, payable to NFS		300		300
	6.75% surplus note, due December 23, 2033, payable to NFS		100		100
	Other		9		7
	Total long-term debt	$	709	$	707

Federal_Income_Taxes_Tables

Federal Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of federal income tax expense	The following table summarizes the components of federal income tax (benefit) expense for the years ended:
		December 31,
	(in millions)	2014			2013			2012
	Current tax expense (benefit)	$	5		$	(33	)	$	(144	)
	Deferred tax (benefit) expense		(152	)		346			243
	Total tax (benefit) expense	$	(147	)	$	313		$	99
Summary of amount computed by applying the U.S. federal income tax rate to income	The following table summarizes how the total federal income tax (benefit) expense differs from the amount computed by applying the U.S. federal income tax rate to net (loss) income for the years ended:
		December 31,
		2014						2013						2012
	(in millions)	Amount			%			Amount			%			Amount			%
	Rate reconciliation:
	Computed (expected tax (benefit) expense)	$	(46	)		35	%	$	469			35	%	$	245			35	%
	Dividends received deduction		(87	)		66	%		(112	)		(8	)%		(75	)		(11	)%
	Tax credits		(53	)		41	%		(82	)		(6	)%		(85	)		(12	)%
	Other, net		39			(30	)%		38			2	%		14			2	%
	Total	$	(147	)		112	%	$	313			23	%	$	99			14	%
Net deferred tax liability	The following table summarizes the tax effects of temporary differences that gave rise to significant components of the net deferred tax liability included in other liabilities in the consolidated balance sheets, as of the dates indicated:
		December 31,
	(in millions)	2014			2013
	Deferred tax assets
	Future policy benefits and claims	$	1,274		$	1,244
	Tax credit carryforwards		355			352
	Other		840			845
	Gross deferred tax assets	$	2,469		$	2,441
	Valuation allowance		(17	)		(17	)
	Net deferred tax assets	$	2,452		$	2,424
	Deferred tax liabilities
	Deferred policy acquisition costs	$	(1,113	)	$	(1,048	)
	Available-for-sale securities		(1,201	)		(821	)
	Derivatives, including embedded derivatives		(267	)		(600	)
	Other		(269	)		(255	)
	Gross deferred tax liabilities	$	(2,850	)	$	(2,724	)
	Net deferred tax liability	$	(398	)	$	(300	)
Uncertain tax positions	The following table is a rollforward of the beginning and ending uncertain tax positions, including permanent and temporary differences, but excluding interest and penalties:
	(in millions)	2014			2013			2012
	Balance at beginning of period	$	36		$	36		$	76
	Additions for current year tax positions		3			2			(2	)
	Additions for prior years tax positions		—			—			25
	Reductions for prior years tax positions		(1	)		(2	)		(63	)
	Balance at end of period	$	38		$	36		$	36

Statutory_Financial_Informatio1

Statutory Financial Information (Tables)	12 Months Ended
	Dec. 31, 2014
Schedule of statutory net income loss and statutory capital and surplus	The following table summarizes the statutory net income (loss) and statutory capital and surplus for the Company’s primary life insurance subsidiaries for the years ended:
		December 31,
	(in millions)	2014			2013			2012
	Statutory net income (loss)
	NLIC	$	341		$	262		$	764
	NLAIC	$	(122	)	$	(103	)	$	(54	)
	Statutory capital and surplus
	NLIC	$	4,408		$	3,550		$	3,837
	NLAIC	$	691		$	534		$	311

Reinsurance_Tables

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of the Effects of Reinsurance on Life, Accident and Health Insurance	The following table summarizes the effects of reinsurance on life, accident and health insurance in force and premiums for the years ended:
		December 31,
	(in millions)	2014			2013			2012
	Premiums
	Direct	$	1,178		$	1,015		$	890
	Assumed from other companies		—			—			—
	Ceded to other companies		(347	)		(291	)		(255	)
	Net	$	831		$	724		$	635
	Life, accident and health insurance in force
	Direct	$	241,936		$	228,095		$	216,002
	Assumed from other companies		5			6			5
	Ceded to other companies		(59,588	)		(58,310	)		(59,895	)
	Net	$	182,353		$	169,791		$	156,112

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of the Company's Business Segment Operating Results	The following tables summarize the Company’s business segment operating results for the years ended:
	(in millions)		Individual			Retirement			Individual		Corporate			Total
			Products and			Plans			Products and		and Other
			Solutions-						Solutions-Life
			Annuity						and NBSG
	December 31, 2014
	Revenues:
	Policy charges		$	1,175		$	107		$	783	$	—		$	2,065
	Premiums			518			—			284		29			831
	Net investment income			546			750			565		39			1,900
	Non-operating net realized investment losses, including other-than-temporary impairment losses1			—			—			—		(1,051	)		(1,051	)
	Other revenues2			(38	)		—			12		10			(16	)
	Total revenues		$	2,201		$	857		$	1,644	$	(973	)	$	3,729
	Benefits and expenses:
	Interest credited to policyholder accounts		$	370		$	482		$	231	$	13		$	1,096
	Benefits and claims			828			—			644		30			1,502
	Amortization of DAC			120			(28	)		122		(7	)		207
	Other expenses, net of deferrals			300			153			348		254			1,055
	Total benefits and expenses		$	1,618		$	607		$	1,345	$	290		$	3,860
	Income before federal income taxes and noncontrolling interests		$	583		$	250		$	299	$	(1,263	)	$	(131	)
	Less:    non-operating net realized investment losses, including other-than-temporary impairment losses1			—			—			—		1,051
	Less:    adjustment to amortization of DAC and other related expenses related to net realized investment gains and losses			—			—			—		(11	)
	Less:    net loss attributable to noncontrolling interest			—			—			—		94
	Pre-tax operating earnings (loss)		$	583		$	250		$	299	$	(129	)
	Assets as of year end		$	72,429		$	30,744		$	29,322	$	11,029		$	143,524
	1	Excluding operating items (trading portfolio realized gains and losses, trading portfolio valuation changes and net realized gains and losses related to hedges on GMDB contracts).
	2	Includes operating items discussed above.
	(in millions)		Individual			Retirement			Individual		Corporate			Total
			Products and			Plans			Products and		and Other
			Solutions-						Solutions-Life
			Annuity						and NBSG
	December 31, 2013
	Revenues:
	Policy charges		$	1,021		$	101		$	727	$	—		$	1,849
	Premiums			416			—			282		26			724
	Net investment income			546			743			544		16			1,849
	Non-operating net realized investment gains, including other-than-temporary impairment losses1			—			—			—		783			783
	Other revenues2			(109	)		—			6		15			(88	)
	Total revenues		$	1,874		$	844		$	1,559	$	840		$	5,117
	Benefits and expenses:
	Interest credited to policyholder accounts		$	377		$	473		$	213	$	4		$	1,067
	Benefits and claims			694			—			636		24			1,354
	Amortization of DAC			185			(2	)		125		66			374
	Other expenses, net of deferrals			295			151			347		188			981
	Total benefits and expenses		$	1,551		$	622		$	1,321	$	282		$	3,776
	Income before federal income taxes and noncontrolling interests		$	323		$	222		$	238	$	558		$	1,341
	Less:    non-operating net realized investment gains, including other-than-temporary impairment losses1			—			—			—		(783	)
	Less:    adjustment to amortization of DAC and other related expenses related to net realized investment gains and losses			—			—			—		70
	Less:    net loss attributable to noncontrolling interest			—			—			—		82
	Pre-tax operating earnings (loss)		$	323		$	222		$	238	$	(73	)
	Assets as of year end		$	68,805		$	29,904		$	27,183	$	7,553		$	133,445
	1	Excluding operating items (trading portfolio realized gains and losses, trading portfolio valuation changes and net realized gains and losses related to hedges on GMDB contracts).
	2	Includes operating items discussed above.
	(in millions)		Individual			Retirement			Individual		Corporate			Total
			Products and			Plans			Products and		and Other
			Solutions-						Solutions-Life
			Annuity						and NBSG
	December 31, 2012
	Revenues:
	Policy charges		$	899		$	94		$	677	$	—		$	1,670
	Premiums			334			—			274		27			635
	Net investment income			551			736			534		4			1,825
	Non-operating net realized investment gains, including of other-than-temporary impairment losses1			—			—			—		427			427
	Other revenues2			(124	)		—			—		23			(101	)
Total revenues		$	1,660		$	830		$	1,485	$	481		$	4,456
Benefits and expenses:
Interest credited to policyholder accounts		$	375		$	457		$	199	$	7		$	1,038
Benefits and claims			613			—			588		26			1,227
Amortization of DAC			185			14			150		226			575
Other expenses, net of deferrals			266			164			307		180			917
Total benefits and expenses		$	1,439		$	635		$	1,244	$	439		$	3,757
Income before federal income taxes and noncontrolling interests		$	221		$	195		$	241	$	42		$	699
Less:    non-operating net realized investment gains, including other-than-temporary impairment losses1			—			—			—		(427	)
Less:    adjustment to amortization of DAC and other related expenses related to net realized investment gains and losses			—			—			—		243
Less:    net loss attributable to noncontrolling interest			—			—			—		61
Pre-tax operating earnings (loss)		$	221		$	195		$	241	$	(81	)
Assets as of year end		$	58,707		$	27,842		$	25,301	$	8,320		$	120,170
1	Excluding operating items (trading portfolio realized gains and losses, trading portfolio valuation changes and net realized gains and losses related to hedges on GMDB contracts).
2	Includes operating items discussed above.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of Significant Accounting Policies (Textual) [Abstract]
Premium method using interest rates	6.60%
Expenses discounted using weighted average interest rates	4.80%
Reversion period	3 years
Fixed maturity securities priced using external source data	87.00%	86.00%
Fixed maturity securities priced using independent pricing services	99.00%	99.00%
Loans delinquent period	90 days
Valuation allowance for policy loan	$0
Government agency discount notes maturity period	12 months
Agreements require a minimum of fair value	102.00%
Fair value of loaned securities	254	116
Cash and cash equivalents liquid investments maturities period	Less than three months
Company's life insurance	4.00%	4.00%	5.00%
Life insurance policies	37.00%	38.00%	40.00%
Federal Home Loan Bank Borrowings [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Amount of collateralized funding agreements outstanding	1,800	913
Federal Home Loan Bank stock held	$35	$18
Equity securities [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Reflect assumed gross returns, discount rate	10.50%
Fixed maturity securities [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Reflect assumed gross returns, discount rate	5.00%

Certain_Long_Duration_Contract

Certain Long Duration Contracts - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	Security
Certain Long Duration Contracts Textual [Abstract]
Number of primary guarantee types	5
Guaranteed return of deposits period one	5 years
Guaranteed return of deposits period two	7 years
Guaranteed return of deposits period three	10 years
Transfer of assets from general account to separate account	$0	$0
Reserve balances on guarantees	401	325
GMDB [Member]
Certain Long Duration Contracts Textual [Abstract]
Paid claims for variable annuity contracts with guarantees	11	22
Reserve balances on guarantees	$76	$55

Summary_of_Annuity_Contracts_w

Summary of Annuity Contracts with Guarantees Invested in General and Separate Accounts (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
GMDB [Member]
Summarizes information regarding variable annuity contracts with guarantees invested in general and separate accounts
Net general account value	$2,790		$2,947
Net separate account value	56,741		53,447
Net amount at risk	313	[1]	250	[1]
Average age	68 years	[2]	67 years	[2]
GMDB [Member] | Return of net deposits [Member]
Summarizes information regarding variable annuity contracts with guarantees invested in general and separate accounts
Net general account value	872		916
Net separate account value	23,079		19,927
Net amount at risk	21	[1]	13	[1]
Average age	65 years	[2]	64 years	[2]
GMDB [Member] | Minimum return or anniversary contract value [Member]
Summarizes information regarding variable annuity contracts with guarantees invested in general and separate accounts
Net general account value	1,918		2,031
Net separate account value	33,662		33,520
Net amount at risk	292	[1]	237	[1]
Average age	69 years	[2]	69 years	[2]
GMAB [Member]
Summarizes information regarding variable annuity contracts with guarantees invested in general and separate accounts
Net general account value	43	[3]	92	[3]
Net separate account value	1,552	[3]	2,383	[3]
Average age	67 years	[2],[3]	64 years	[2],[3]
GLWB [Member]
Summarizes information regarding variable annuity contracts with guarantees invested in general and separate accounts
Net general account value	135		178
Net separate account value	31,031		28,071
Net amount at risk	195	[1]	74	[1]
Average age	66 years	[2]	64 years	[2]
GMIB [Member]
Summarizes information regarding variable annuity contracts with guarantees invested in general and separate accounts
Net general account value	45		49
Net separate account value	451		510
Net amount at risk	$1	[1]
Average age	66 years	[2]	64 years	[2]
[1]	Net amount at risk is calculated on a policy-level basis and equals the respective guaranteed benefit less the account value (or zero if the account value exceeds the guaranteed benefit).
[2]	Represents the weighted average attained age of contractholders.
[3]	Contracts with the hybrid accumulation/withdrawal benefits are included with the accumulation benefits contracts.

Summary_of_Reserve_Balances_fo

Summary of Reserve Balances for Variable Annuity Contracts With Guarantees (Detail) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Summarizes the reserve balances, for variable annuity contracts with guarantees
Reserve balances on guarantees	$401		$325
GMDB [Member]
Summarizes the reserve balances, for variable annuity contracts with guarantees
Reserve balances on guarantees	76		55
GMAB [Member]
Summarizes the reserve balances, for variable annuity contracts with guarantees
Reserve balances on guarantees	-3	[1],[2]	19	[1],[2]
GLWB [Member]
Summarizes the reserve balances, for variable annuity contracts with guarantees
Reserve balances on guarantees	-174	[1]	1,075	[1]
GMIB [Member]
Summarizes the reserve balances, for variable annuity contracts with guarantees
Reserve balances on guarantees	$1		$2
[1]	The changes in reserve balances for withdrawal benefits and accumulation benefits were primarily driven by declines in key interest rates, partially offset by rising equity markets during 2014. Refer to Note 7 for discussion of the related derivative programs.
[2]	Contracts with the hybrid accumulation/withdrawal benefits are included with the accumulation benefits contracts.

Summary_of_Account_Balances_of

Summary of Account Balances of Deferred Variable Annuity Contracts With Guarantees Invested in Separate Accounts (Detail) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Summarizes account balances of deferred variable annuity
Deferred variable annuity	$56,741	[1]	$53,447	[1]
Bonds [Member]
Summarizes account balances of deferred variable annuity
Deferred variable annuity	5,280		5,685
Domestic equity [Member]
Summarizes account balances of deferred variable annuity
Deferred variable annuity	47,316		43,505
International Equity [Member]
Summarizes account balances of deferred variable annuity
Deferred variable annuity	2,969		3,179
Total mutual funds [Member]
Summarizes account balances of deferred variable annuity
Deferred variable annuity	55,565		52,369
Money market funds [Member]
Summarizes account balances of deferred variable annuity
Deferred variable annuity	$1,176		$1,078
[1]	Excludes $31.3 billion and $30.6 billion as of December 31, 2014 and 2013, respectively, of separate account assets not related to deferred variable annuity contracts with guarantees, primarily attributable to retirement plan, variable universal life and COLI products.

Summary_of_Account_Balances_of1

Summary of Account Balances of Deferred Variable Annuity Contracts With Guarantees Invested in Separate Accounts (Parenthetical) (Detail) (Separate Account Value [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Billions, unless otherwise specified
Separate Account Value [Member]
Summarizes account balances of deferred variable annuity
Deferred variable annuity	$31.30	$30.60

Summary_of_Universal_and_Unive

Summary of Universal and Universal Variable Life Insurance Contracts With No Larger Guarantees Invested in general and Separate Accounts (Detail) (Universal Life [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Universal Life [Member]
Summarizes information regarding universal and variable universal life insurance contracts with no lapse guarantees invested in general and separate accounts
General account value	$1,954		$1,522	[1]
Separate account value	2,191		2,235	[1]
Adjusted insurance in force	$41,484	[2]	$36,956	[1],[2]
Average age	51 years	[3]	51 years	[1],[3]
[1]	Amounts above are based on all policies with no-lapse guarantees. Previously, only those policies with a no-lapse guarantee carrying a reserve were included in the disclosure.
[2]	The adjusted insurance in force is calculated on a policy-level basis and equals the respective guaranteed death benefit less the account value.
[3]	Represents the weighted average attained age of contractholders.

Summary_of_Changes_in_DAC_Bala

Summary of Changes in DAC Balance (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Policy Acquisition Costs
Balance at beginning of year	$3,778	$3,249	$3,487
Capitalization of DAC	685	604	470
Amortization of DAC, excluding unlocks	-397	-373	-525
Amortization of DAC related to unlocks	190	-1	-50
Adjustments to DAC related to unrealized gains and losses on available-for-sale securities	-193	299	-133
Balance at end of year	$4,063	$3,778	$3,249

Deferred_Policy_Acquisition_Co2

Deferred Policy Acquisition Costs and Value of Business Acquired - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Policy Acquisition Costs Disclosures [Abstract]
Amortization of DAC related to unlocks	($190)	$1	$50

Summary_of_Amortized_Cost_Unre

Summary of Amortized Cost, Unrealized Gains and Losses and Fair Value of Available For Sale Securities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	$33,204	$31,008
Available-for-sale Securities, Gross unrealized gains	2,510	1,817
Available-for-sale Securities, Gross unrealized losses	275	552
Available-for-sale Securities, Fair value	35,439	32,273
Fixed maturity securities [Member]
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	33,198	31,002
Available-for-sale Securities, Gross unrealized gains	2,495	1,799
Available-for-sale Securities, Gross unrealized losses	275	552
Available-for-sale Securities, Fair value	35,418	32,249
Fixed maturity securities [Member] | U.S. Treasury securities and obligations of U.S. Government corporations and agencies [Member]
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	448	484
Available-for-sale Securities, Gross unrealized gains	79	79
Available-for-sale Securities, Gross unrealized losses		2
Available-for-sale Securities, Fair value	527	561
Fixed maturity securities [Member] | Obligations of states, political subdivisions and foreign governments [Member]
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	1,966	1,892
Available-for-sale Securities, Gross unrealized gains	320	111
Available-for-sale Securities, Gross unrealized losses	1	40
Available-for-sale Securities, Fair value	2,285	1,963
Fixed maturity securities [Member] | Corporate public securities [Member]
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	19,851	18,004
Available-for-sale Securities, Gross unrealized gains	1,519	1,076
Available-for-sale Securities, Gross unrealized losses	120	295
Available-for-sale Securities, Fair value	21,250	18,785
Fixed maturity securities [Member] | Corporate private securities [Member]
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	4,398	4,374
Available-for-sale Securities, Gross unrealized gains	286	258
Available-for-sale Securities, Gross unrealized losses	34	38
Available-for-sale Securities, Fair value	4,650	4,594
Fixed maturity securities [Member] | Residential mortgage-backed securities [Member]
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	3,694	3,919
Available-for-sale Securities, Gross unrealized gains	190	163
Available-for-sale Securities, Gross unrealized losses	45	79
Available-for-sale Securities, Fair value	3,839	4,003
Fixed maturity securities [Member] | Commercial mortgage-backed securities [Member]
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	1,431	1,439
Available-for-sale Securities, Gross unrealized gains	74	86
Available-for-sale Securities, Gross unrealized losses	3	21
Available-for-sale Securities, Fair value	1,502	1,504
Fixed maturity securities [Member] | Other asset-backed securities [Member]
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	1,410	890
Available-for-sale Securities, Gross unrealized gains	27	26
Available-for-sale Securities, Gross unrealized losses	72	77
Available-for-sale Securities, Fair value	1,365	839
Equity securities [Member]
Available-for-Sale Securities
Available-for-Sale Securities, Amortized cost	6	6
Available-for-sale Securities, Gross unrealized gains	15	18
Available-for-sale Securities, Fair value	$21	$24

Summary_of_Amortized_Cost_and_

Summary of Amortized Cost and Fair Value of Fixed Maturity Securities, By Maturity (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Summarizes the amortized cost and fair value of fixed maturity securities
Subtotal, Fair value	$35,418	$32,249
Available-for-Sale Securities, Amortized cost	33,204	31,008
Available-for-sale Securities, Fair value	35,439	32,273
Fixed maturity securities [Member]
Summarizes the amortized cost and fair value of fixed maturity securities
Due in one year or less, Amortized cost	1,018
Due in one year or less, Fair Value	1,037
Due after one year through five years, Amortized cost	9,196
Due after one year through five years, Fair value	9,898
Due after five years through ten years, Amortized cost	8,267
Due after five years through ten years, Fair value	8,617
Due after ten years, Amortized cost	8,182
Due after ten years, Fair value	9,160
Subtotal, Amortized cost	26,663
Subtotal, Fair value	28,712
Available-for-Sale Securities, Amortized cost	33,198	31,002
Available-for-sale Securities, Fair value	35,418	32,249
Fixed maturity securities [Member] | Residential mortgage-backed securities [Member]
Summarizes the amortized cost and fair value of fixed maturity securities
Available-for-Sale Securities, Amortized cost	3,694	3,919
Available-for-sale Securities, Fair value	3,839	4,003
Fixed maturity securities [Member] | Commercial mortgage-backed securities [Member]
Summarizes the amortized cost and fair value of fixed maturity securities
Available-for-Sale Securities, Amortized cost	1,431	1,439
Available-for-sale Securities, Fair value	1,502	1,504
Fixed maturity securities [Member] | Other asset-backed securities [Member]
Summarizes the amortized cost and fair value of fixed maturity securities
Available-for-Sale Securities, Amortized cost	1,410	890
Available-for-sale Securities, Fair value	$1,365	$839

Summary_of_Components_of_Net_U

Summary of Components of Net Unrealized Gains and Losses (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Summarizes components of net unrealized gains and losses on available-for-sale securities
Net unrealized gains on available-for-sale securities, before adjustments, taxes and fair value hedging	$2,235		$1,265
Net unrealized gains on available-for-sale securities, before adjustments and taxes	2,235	[1]	1,265	[1]
Adjustment to DAC and other expense	-372		-176
Adjustment to future policy benefits and claims	-159		-89
Adjustment to policyholder dividend obligation	-120		-85
Deferred federal income tax expense	-548		-314
Net unrealized gains on available-for-sale securities	$1,036		$601
[1]	Includes net unrealized losses of $9 million and $40 million as of December 31, 2014 and 2013, respectively, related to the non-credit portion of other-than-temporarily impaired securities.

Summary_of_Components_of_Net_U1

Summary of Components of Net Unrealized Gains and Losses (Parenthetical) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Non-credit portion of other-than-temporary impairments	$9	$40

Summary_of_Change_in_Net_Unrea

Summary of Change in Net Unrealized Gains and Losses Reported in Accumulated Other Comprehensive Income (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summarizes the change in net unrealized gains and losses on available-for-sale securities
Balance at beginning of period	$601	$1,264
Unrealized gains and losses arising during the year:
Net unrealized gains (losses) on available-for-sale securities before adjustments	939	-1,657
Non-credit impairments and subsequent changes in fair value of impaired debt securities	31	8
Net adjustment to DAC and other expense	-196	306
Net adjustment to future policy benefits and claims	-70	206
Net adjustment to policyholder dividend obligations	-35	92
Related federal income tax (expense) benefit	-234	366
Unrealized gains (losses) on available-for-sale securities	435	-679
Reclassification adjustment for net losses realized on available-for-sale securities, net of tax benefit ($0 and $8 as of December 31, 2014 and 2013, respectively)		-16
Net unrealized gains (losses) on available-for-sale securities	435	-663	571
Balance at end of period	$1,036	$601	$1,264

Summary_of_Change_in_Net_Unrea1

Summary of Change in Net Unrealized Gains and Losses Reported in Accumulated Other Comprehensive Income (Parenthetical) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Summarizes the change in net unrealized gains and losses on available-for-sale securities
Reclassification adjustments to net investment losses, tax benefit	$0	$8

Summary_of_Available_for_Sale_

Summary of Available for Sale Securities, By Asset Class, in Unrealized Loss Position (Detail) (Fixed maturity securities [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Fair value
Less than or equal to one year, Fair value	$3,161	[1]	$7,959	[1]
More than one year, Fair value	3,015	[1]	1,412	[1]
Gross unrealized losses
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Less than or equal to one year	97	[1]	363	[1]
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, More than one year	178	[1],[2]	189	[1],[2]
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Total	275	[1]	552	[1]
Corporate public securities [Member]
Fair value
Less than or equal to one year, Fair value	1,642		4,889
More than one year, Fair value	1,578		442
Gross unrealized losses
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Less than or equal to one year	63		256
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, More than one year	57	[2]	39	[2]
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Total	120		295
Residential mortgage-backed securities [Member]
Fair value
Less than or equal to one year, Fair value	268		725
More than one year, Fair value	487		604
Gross unrealized losses
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Less than or equal to one year	2		16
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, More than one year	43	[2]	63	[2]
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Total	45		79
Other asset-backed securities [Member]
Fair value
Less than or equal to one year, Fair value	662		507
More than one year, Fair value	493		144
Gross unrealized losses
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Less than or equal to one year	5		6
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, More than one year	67	[2]	71	[2]
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Total	72		77
Other [Member]
Fair value
Less than or equal to one year, Fair value	589		1,838
More than one year, Fair value	457		222
Gross unrealized losses
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Less than or equal to one year	27		85
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, More than one year	11	[2]	16	[2]
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, Total	$38		$101
[1]	Represents 541 and 816 available-for-sale securities in an unrealized loss position as of December 31, 2014 and 2013, respectively.
[2]	As of December 31, 2014 and 2013, there were $66 million and $82 million, respectively, of unrealized losses related to available-for-sale securities with a fair value to amortized cost ratio of less than 80%.

Summary_of_Available_for_Sale_1

Summary of Available for Sale Securities, By Asset Class, in Unrealized Loss Position (Parenthetical) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Net Investment Income [Line Items]
Net unrealized (losses) gains on available-for-sale securities	$435		($663)		$571
Fixed maturity securities [Member]
Net Investment Income [Line Items]
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, More than one year	178	[1],[2]	189	[1],[2]
Ratio of estimated fair value to amortized cost	80.00%		80.00%
Net unrealized (losses) gains on available-for-sale securities	541		816
Less than 80.0% [Member] | Fixed maturity securities [Member]
Net Investment Income [Line Items]
Gross unrealized losses based on the ratio of estimated fair value to amortized cost, More than one year	$66		$82
[1]	Represents 541 and 816 available-for-sale securities in an unrealized loss position as of December 31, 2014 and 2013, respectively.
[2]	As of December 31, 2014 and 2013, there were $66 million and $82 million, respectively, of unrealized losses related to available-for-sale securities with a fair value to amortized cost ratio of less than 80%.

Summary_Of_Amortized_Cost_Of_M

Summary Of Amortized Cost Of Mortgage Loans (Detail) (Mortgage loans, net of allowance [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Summary of the amortized cost of mortgage loans
Total amortized cost	$7,296	$6,376
Total valuation allowance	26	35
Mortgage loans, net of allowance	7,270	6,341
Non-specific reserves [Member]
Summary of the amortized cost of mortgage loans
Amortized cost	7,279	6,350
Non-specific reserves	21	29
Specific reserve [Member]
Summary of the amortized cost of mortgage loans
Amortized cost	17	26
Specific reserves	$5	$6

Summary_Of_Activity_In_Valuati

Summary Of Activity In Valuation Allowance For Mortgage Loans (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Activity in the valuation allowance for mortgage loans
Balance at end of period	$0
Mortgage loans, net of allowance [Member]
Activity in the valuation allowance for mortgage loans
Balance at beginning of year	35		44		60
Current period provision	-8	[1]	-4	[1]	2	[1]
Recoveries	-1	[2]	-5	[2]	-15	[2]
Charge offs and other					-3
Balance at end of period	$26		$35		$44
[1]	Includes specific reserve provisions and all changes in non-specific reserves.
[2]	Includes recoveries on sales and increases in the valuation of loans with specific reserves.

Investments_Additional_Informa

Investments - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments (Textual) [Abstract]
Interest income recognized	$1,000,000	$3,000,000
Average recorded investment	16,000,000	30,000,000
No mortgage loans past due and still accruing	90 days
Available-for-sale securities, carrying value	35,439,000,000	32,273,000,000
LIHTC Funds Sold	1,300,000,000	1,200,000,000
Cumulative yields after tax maturity	2029
Effective period of Guarantees	15 years	15 years
Maximum amount payment to investors under guarantees	744,000,000
Net assets of all consolidated VIEs	640,000,000	680,000,000
Investments in tax credit funds carrying value	113,000,000	104,000,000
Investments in tax credit funds	17,000,000	29,000,000
Proceeds from sales of available-for-sale securities	647,000,000	1,091,000,000	796,000,000
Gross realized gains	17,000,000	31,000,000	47,000,000
Gross realized losses	10,000,000	50,000,000	20,000,000
Industrial Property [Member]
Investments (Textual) [Abstract]
Carrying value of impaired mortgage loans, net of allowance	12,000,000	20,000,000
Industrial Property [Member] | Specific reserve [Member]
Investments (Textual) [Abstract]
Specific reserves	5,000,000	6,000,000
Deposits [Member]
Investments (Textual) [Abstract]
Available-for-sale securities, carrying value	8,000,000	8,000,000
Available-for-sale securities, collateral value	683,000,000	849,000,000
Mortgage loans, net of allowance [Member]
Investments (Textual) [Abstract]
Mortgage Loans	0
Other [Member]
Investments (Textual) [Abstract]
Other long-term investments	580,000,000	554,000,000
Other Assets [Member]
Investments (Textual) [Abstract]
Other assets	109,000,000	182,000,000
Other Liabilities [Member]
Investments (Textual) [Abstract]
Other liabilities	$75,000,000	$82,000,000

Summary_of_LTV_Ratio_and_DSC_R

Summary of LTV Ratio and DSC Ratios of Mortgage Loan (Detail) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	$7,296	[1]	$6,376	[2]
Apartment [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	2,284		1,870
Warehouse [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	1,200		1,089
Office [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	1,040		905
Retail [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	2,581		2,298
Other [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	191		214
Less than 80% [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	6,988	[1]	6,025	[2]
Less than 80% [Member] | Apartment [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	2,156		1,788
Less than 80% [Member] | Warehouse [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	1,131		951
Less than 80% [Member] | Office [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	1,004		837
Less than 80% [Member] | Retail [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	2,506		2,236
Less than 80% [Member] | Other [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	191		213
80% - less than 90% [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	225	[1]	175	[2]
80% - less than 90% [Member] | Apartment [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	111		52
80% - less than 90% [Member] | Warehouse [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	34		52
80% - less than 90% [Member] | Office [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	16		30
80% - less than 90% [Member] | Retail [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	64		41
90% or greater [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	83	[1]	176	[2]
90% or greater [Member] | Apartment [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	17		30
90% or greater [Member] | Warehouse [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	35		86
90% or greater [Member] | Office [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	20		38
90% or greater [Member] | Retail [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	11		21
90% or greater [Member] | Other [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total			1
Greater than 1.10 [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	6,902	[1]	5,978	[2]
Greater than 1.10 [Member] | Apartment [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	2,252		1,857
Greater than 1.10 [Member] | Warehouse [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	1,048		893
Greater than 1.10 [Member] | Office [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	990		800
Greater than 1.10 [Member] | Retail [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	2,421		2,214
Greater than 1.10 [Member] | Other [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	191		214
1.00-1.10 [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	247	[1]	232	[2]
1.00-1.10 [Member] | Apartment [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	26		6
1.00-1.10 [Member] | Warehouse [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	89		122
1.00-1.10 [Member] | Office [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	4		43
1.00-1.10 [Member] | Retail [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	128		61
Less than 1.00 [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	147	[1]	166	[2]
Less than 1.00 [Member] | Apartment [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	6		7
Less than 1.00 [Member] | Warehouse [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	63		74
Less than 1.00 [Member] | Office [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	46		62
Less than 1.00 [Member] | Retail [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Total	$32		$23
[1]	As of December 31, 2014, the weighted average DSC ratios for the respective LTV ratio ranges above were 1.97, 1.27 and 0.90, with a total weighted average DSC ratio of 1.93. As of December 31, 2014, the weighted average LTV ratios for the respective DSC ratio ranges above were 60%, 59% and 90%, with a total weighted average LTV ratio of 60%.
[2]	As of December 31, 2013, the weighted average DSC ratios for the respective LTV ratio ranges above were 1.77, 1.22 and 1.00, with a total weighted average DSC ratio of 1.74. As of December 31, 2013, the weighted average LTV ratios for the respective DSC ratio ranges above were 60%, 61% and 91%, with a total weighted average LTV ratio of 61%.

Summary_of_LTV_Ratio_and_DSC_R1

Summary of LTV Ratio and DSC Ratios of Mortgage Loan (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Weighted-average DSC ratio	1.93	1.74
Weighted-average LTV ratio	0.6	0.61
Less than 80% [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Weighted-average DSC ratio	1.97	1.77
80% - less than 90% [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Weighted-average DSC ratio	1.27	1.22
90% or greater [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Weighted-average DSC ratio	0.9	1
Greater than 1.10 [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Weighted-average LTV ratio	0.6	0.6
1.00-1.10 [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Weighted-average LTV ratio	0.59	0.61
Less than 1.00 [Member]
Summary of loan-to-value ratio and debt service coverage ratios of the commercial mortgage loan portfolio
Weighted-average LTV ratio	0.9	0.91

Summary_of_Net_Investment_Inco

Summary of Net Investment Income by Investment Type (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of net investment income by investment type
Gross investment income	$1,959	$1,908	$1,880
Investment expenses	59	59	55
Net investment income	1,900	1,849	1,825
Fixed maturity securities [Member]
Summary of net investment income by investment type
Gross investment income	1,575	1,565	1,506
Mortgage loans, net of allowance [Member]
Summary of net investment income by investment type
Gross investment income	362	348	366
Policy loans [Member]
Summary of net investment income by investment type
Gross investment income	51	52	53
Other [Member]
Summary of net investment income by investment type
Gross investment income	$29	$57	$45

Summary_of_Net_Realized_Invest

Summary of Net Realized Investment Gains And Losses (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Net Realized Investment Gains and Losses
Net realized derivative (losses) gains	($1,087)		$705		$314
Realized gains on sales	31		32		48
Realized losses on sales	-19		-54		-23
Other	2				12
Net realized investment (losses) gains before other-than-temporary impairments on fixed maturity securities	-1,073		683		351
Other-than-temporary impairments on fixed maturity securities	-5	[1]	-5	[1]	-32	[1]
Net realized investment (losses) gains, including other-than-temporary impairments	($1,078)		$678		$319
[1]	Other-than-temporary impairments on fixed maturity securities are net $1 million, $6 million and $36 million of non-credit losses included in other comprehensive income for the years ended December 31, 2014, 2013 and 2012, respectively.

Summary_of_Net_Realized_Invest1

Summary of Net Realized Investment Gains And Losses (Parenthetical) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Realized Investment Gains and Losses
Non-credit losses included in other comprehensive income	$1	$6	$36

Summary_of_Cumulative_Credit_L

Summary of Cumulative Credit Losses (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Other-Than-Temporary Impairment Losses on Debt Securities
Cumulative credit losses at beginning of year	($272)	[1]	($289)	[1]	($328)	[1]
New credit losses	-2		-3		-18
Incremental credit losses	-4		-3		-10
Losses related to securities included in the beginning balance sold or paid down during the period	24		23		67
Cumulative credit losses at end of year	($254)	[1]	($272)	[1]	($289)	[1]
[1]	Cumulative credit losses are defined as amounts related to the Company's credit portion of the other-than-temporary impairment losses on debt securities that the Company does not intend to sell and that it is not more likely than not the Company will be required to sell prior to recovery of the amortized cost basis.

Summary_of_Fair_Value_and_Rela

Summary of Fair Value and Related Notional Amounts of Derivative Instruments (Detail) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Summary of fair value of derivative instruments
Derivative asset, Fair value	$3,285		$2,333
Derivative liability, Fair value	2,908		2,410
Accrued Interest [Member]
Summary of fair value of derivative instruments
Derivative asset, Fair value	243		196
Derivative liability, Fair value	244		227
Designated as Hedging Instrument [Member]
Summary of fair value of derivative instruments
Derivative asset, Fair value	29		1
Derivative asset, Notional amount	381		6
Derivative liability, Fair value	9		26
Derivative liability, Notional amount	176		345
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Summary of fair value of derivative instruments
Derivative asset, Fair value	2,602		1,787
Derivative asset, Notional amount	32,829		26,156
Derivative liability, Fair value	2,611		2,100
Derivative liability, Notional amount	32,756		29,715
Not Designated as Hedging Instrument [Member] | Equity Contracts [Member]
Summary of fair value of derivative instruments
Derivative asset, Fair value	411		343
Derivative asset, Notional amount	5,990		6,556
Not Designated as Hedging Instrument [Member] | Total Return Swap [Member]
Summary of fair value of derivative instruments
Derivative asset, Fair value			6
Derivative asset, Notional amount			1,101
Derivative liability, Fair value	41		52
Derivative liability, Notional amount	2,808		1,183
Not Designated as Hedging Instrument [Member] | Other Derivative Contracts [Member]
Summary of fair value of derivative instruments
Derivative liability, Fair value	3		5
Derivative liability, Notional amount	2		2
Other Assets Liabilities [Member]
Summary of fair value of derivative instruments
Derivative asset, Fair value	3,042	[1]	2,137	[1]
Derivative asset, Notional amount	39,200	[1]	33,819	[1]
Derivative liability, Fair value	2,664	[1]	2,183	[1]
Derivative liability, Notional amount	$35,742	[1]	$31,245	[1]
[1]	Derivative assets and liabilities are included in other assets and other liabilities, respectively, in the consolidated balance sheets.

Derivative_Instruments_Additio

Derivative Instruments - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments (Textual) [Abstract]
Derivative asset, Fair value	$3,285,000,000	$2,333,000,000
Fair value of Derivative subject to offsetting by collateral agreement	2,600,000,000	1,700,000,000
Cash collateral from derivative counterparties	535,000,000	382,000,000
Off balance sheet Collateral	64,000,000	29,000,000
Net uncollateralized derivative asset and liability	Immaterial	Immaterial
Derivative liability, Fair value	2,908,000,000	2,410,000,000
Posted cash collateral	330,000,000	435,000,000
Pledged securities of fair value	$174,000,000	$173,000,000

Summary_of_Gains_and_Losses_fo

Summary of Gains and Losses for Derivative Instruments Recognized in Net Realized Investment Gains and Losses in Statements of Operations (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Summary of realized gains and losses for derivative instruments
Total derivative losses	($108)	[1]	($1,302)	[1]	($1,082)	[1]
Change in embedded derivatives on guaranteed benefit annuity programs	-1,271	[2]	1,751	[2]	1,185	[2]
Other revenue on guaranteed benefit annuity programs	292		256		211
Change in embedded derivative liabilities and related fees	-979		2,007		1,396
Net realized derivative gains	-1,087		705		314
Designated as Hedging Instrument [Member]
Summary of realized gains and losses for derivative instruments
Total derivative losses			-1		-1
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Summary of realized gains and losses for derivative instruments
Total derivative losses	142		-209		-125
Not Designated as Hedging Instrument [Member] | Equity Contracts [Member]
Summary of realized gains and losses for derivative instruments
Total derivative losses	-79		-776		-665
Not Designated as Hedging Instrument [Member] | Total Return Swap [Member]
Summary of realized gains and losses for derivative instruments
Total derivative losses	-195		-321		-343
Not Designated as Hedging Instrument [Member] | Other Derivative Contracts [Member]
Summary of realized gains and losses for derivative instruments
Total derivative losses	4		-9		-1
Not Designated as Hedging Instrument [Member] | Net Interest Settlements [Member]
Summary of realized gains and losses for derivative instruments
Total derivative losses	$20		$14		$53
[1]	Included in total derivative losses are economic hedging gains (losses) of $941 million, $(1.8) billion and $(827) million related to the guaranteed benefit annuity programs for the years ended December 31, 2014, 2013 and 2012, respectively. Also included are economic hedging (losses) gains of $(1.0) billion, $645 million and $(129) million, respectively, related to the program that protects against the negative impact of higher interest rates on the Company's statutory surplus position.
[2]	For the individual variable annuity business, the annual comprehensive review of model assumptions included a favorable impact for the years ended December 31, 2014 and 2013, primarily due to model enhancements and updated assumptions for discounting and benefit utilization, partially offset by mortality and lapse rates.

Summary_of_Gains_and_Losses_fo1

Summary of Gains and Losses for Derivative Instruments Recognized in Net Realized Investment Gains and Losses in Statements of Operations (Parenthetical) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
GBAP [Member]
Summary of realized gains and losses for derivative instruments
Hedging gains/losses	$941	($1,800)	($827)
Negative Impact of Higher Interest Rate Risk [Member]
Summary of realized gains and losses for derivative instruments
Hedging gains/losses	($1,000)	$645	($129)

Summary_of_Assets_and_Liabilit

Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Assets
Separate account assets	$56,741	[1]	$53,447	[1]
Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	36,395		32,715
Derivative instruments - assets	3,042		2,137
Separate account assets	88,076		84,069
Assets at fair value	127,513		118,921
Liabilities
Total future policy benefits and claims	-261		1,010
Derivative instruments - liabilities	-2,664		-2,183
Liabilities at fair value	-2,925		-1,173
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value	1,665		1,476
Derivative instruments - assets			0
Separate account assets	84,583		80,647
Assets at fair value	86,248		82,123
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	33,427		30,106
Derivative instruments - assets	2,631		1,794
Separate account assets	1,387		1,339
Assets at fair value	37,445		33,239
Liabilities
Derivative instruments - liabilities	-2,661		-2,178
Liabilities at fair value	-2,661		-2,178
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value	1,303		1,133
Derivative instruments - assets	411		343
Separate account assets	2,106		2,083
Assets at fair value	3,820		3,559
Liabilities
Total future policy benefits and claims	-261		1,010
Derivative instruments - liabilities	-3		-5
Liabilities at fair value	-264		1,005
Living Benefits [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities
Total future policy benefits and claims	-177		1,094
Living Benefits [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Liabilities
Total future policy benefits and claims	-177		1,094
Indexed Products [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities
Total future policy benefits and claims	-84		-84
Indexed Products [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Liabilities
Total future policy benefits and claims	-84		-84
Fixed maturity securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	35,418		32,249
Fixed maturity securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value	1,623		1,412
Fixed maturity securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	32,528		29,749
Fixed maturity securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value	1,267		1,088
Fixed maturity securities [Member] | U.S. Treasury securities and obligations of U.S. Government corporations and agencies [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	527		561
Fixed maturity securities [Member] | U.S. Treasury securities and obligations of U.S. Government corporations and agencies [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value	523		557
Fixed maturity securities [Member] | U.S. Treasury securities and obligations of U.S. Government corporations and agencies [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	1		1
Fixed maturity securities [Member] | U.S. Treasury securities and obligations of U.S. Government corporations and agencies [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value	3		3
Fixed maturity securities [Member] | Obligations of states, political subdivisions and foreign governments [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	2,285		1,963
Fixed maturity securities [Member] | Obligations of states, political subdivisions and foreign governments [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value	66		63
Fixed maturity securities [Member] | Obligations of states, political subdivisions and foreign governments [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	2,219		1,900
Fixed maturity securities [Member] | Obligations of states, political subdivisions and foreign governments [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value			0
Fixed maturity securities [Member] | Corporate public securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	21,250		18,785
Fixed maturity securities [Member] | Corporate public securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value			1
Fixed maturity securities [Member] | Corporate public securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	21,158		18,705
Fixed maturity securities [Member] | Corporate public securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value	92		79
Fixed maturity securities [Member] | Corporate private securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	4,650		4,594
Fixed maturity securities [Member] | Corporate private securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value			0
Fixed maturity securities [Member] | Corporate private securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	3,659		3,791
Fixed maturity securities [Member] | Corporate private securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value	991		803
Fixed maturity securities [Member] | Residential mortgage-backed securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	3,839		4,003
Fixed maturity securities [Member] | Residential mortgage-backed securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value	1,034		791
Fixed maturity securities [Member] | Residential mortgage-backed securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	2,796		3,203
Fixed maturity securities [Member] | Residential mortgage-backed securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value	9		9
Fixed maturity securities [Member] | Commercial mortgage-backed securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	1,502		1,504
Fixed maturity securities [Member] | Commercial mortgage-backed securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value			0
Fixed maturity securities [Member] | Commercial mortgage-backed securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	1,499		1,504
Fixed maturity securities [Member] | Commercial mortgage-backed securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value	3		0
Fixed maturity securities [Member] | Other asset-backed securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	1,365		839
Fixed maturity securities [Member] | Other asset-backed securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value			0
Fixed maturity securities [Member] | Other asset-backed securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	1,196		645
Fixed maturity securities [Member] | Other asset-backed securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value	169		194
Other [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments at fair value	977	[2]	466	[3]
Other [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets
Investments at fair value	42	[2]	64	[3]
Other [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets
Investments at fair value	899	[2]	357	[3]
Other [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets
Investments at fair value	$36	[2]	$45	[3]
[1]	Excludes $31.3 billion and $30.6 billion as of December 31, 2014 and 2013, respectively, of separate account assets not related to deferred variable annuity contracts with guarantees, primarily attributable to retirement plan, variable universal life and COLI products.
[2]	Other investments at fair value includes $21 million of trading securities as of December 31, 2014.
[3]	Other investments at fair value includes $31 million of trading securities as of December 31, 2013.

Summary_of_Assets_and_Liabilit1

Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Parenthetical) (Detail) (Other [Member], Trading assets [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Other [Member] | Trading assets [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Investments at fair value	$21	$31

Rollforward_of_Level_3_Assets_

Rollforward of Level 3 Assets and Liabilities Held at Fair Value on a Recurring Basis (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Significant unobservable inputs (Level 3) to determine fair value
Assets, Beginning balance	$3,559		$4,106
Assets, Net gains (losses) In operations	64	[1]	-396	[2]
Assets, Net gains (losses) In OCI	22		7
Assets, Purchases	167		249
Assets, Sales	-275		-415
Assets, Transfers in to Level 3	400		142
Assets, Transfers out of Level 3	-117		-134
Assets, ending balance	3,820		3,559
Liability value, beginning balance	1,005	[3]	-753	[3]
Net gains (loss) In operations	-1,269	[1],[3]	1,758	[2],[3]
Liability, Net gains (losses) In operations			0	[3]
Liability, Purchases			0	[3]
Liability, Sales			0	[3]
Liability, Transfers into Level 3			0	[3]
Liability, Transfers out of Level 3			0	[3]
Liability value, ending balance	-264	[3]	1,005	[3]
Fixed maturity securities [Member]
Significant unobservable inputs (Level 3) to determine fair value
Assets, Beginning balance	1,088	[3],[4]	1,197	[4]
Assets, Net gains (losses) In operations	-5	[1],[3]	-1	[2],[4]
Assets, Net gains (losses) In OCI	21	[3]	1	[4]
Assets, Purchases	121	[3]	115	[4]
Assets, Sales	-241	[3]	-232	[4]
Assets, Transfers in to Level 3	400	[3]	142	[4]
Assets, Transfers out of Level 3	-117	[3]	-134	[4]
Assets, ending balance	1,267	[3]	1,088	[3],[4]
Other [Member]
Significant unobservable inputs (Level 3) to determine fair value
Assets, Beginning balance	45		62
Assets, Net gains (losses) In operations	6	[1]	-6	[2]
Assets, Net gains (losses) In OCI	1		6
Assets, Purchases			5
Assets, Sales	-16		-22
Assets, Transfers in to Level 3			0
Assets, Transfers out of Level 3			0
Assets, ending balance	36		45
Derivative Assets [Member]
Significant unobservable inputs (Level 3) to determine fair value
Assets, Beginning balance	343		822
Assets, Net gains (losses) In operations	40	[1]	-447	[2]
Assets, Net gains (losses) In OCI			0
Assets, Purchases	46		129
Assets, Sales	-18		-161
Assets, Transfers in to Level 3			0
Assets, Transfers out of Level 3			0
Assets, ending balance	411		343
Separate Account Assets [Member]
Significant unobservable inputs (Level 3) to determine fair value
Assets, Beginning balance	2,083		2,025
Assets, Net gains (losses) In operations	23	[1]	58	[2]
Assets, Net gains (losses) In OCI			0
Assets, Purchases			0
Assets, Sales			0
Assets, Transfers in to Level 3			0
Assets, Transfers out of Level 3			0
Assets, ending balance	$2,106		$2,083
[1]	Net gains and losses included in operations are reported in net realized investment gains and losses and interest credited to policyholder accounts. The net unrealized gains on separate account assets are attributable to contractholders and therefore are not included in the Company's earnings. The change in unrealized (losses) gains included in operations on assets and liabilities still held at the end of the year was $(1.3) billion for future policy benefits and claims, $154 million for derivative assets, and $6 million for other investments at fair value.
[2]	Net gains and losses included in operations are reported in net realized investment gains and losses and interest credited to policyholder accounts. The net unrealized gains on separate account assets are attributable to contractholders and therefore are not included in the Company's earnings. The change in unrealized gains (losses) included in operations on assets and liabilities still held as of the end of the year was $1.8 billion for future policy benefits and claims, $(297) million for derivative assets and $(6) million for other investments at fair value.
[3]	Non-binding broker quotes were utilized to determine a fair value of all Level 3 derivative assets and liabilities.
[4]	Non-binding broker quotes were utilized to determine a fair value of $924 million of total fixed maturity securities as of December 31, 2013.

Rollforward_of_Level_3_Assets_1

Rollforward of Level 3 Assets and Liabilities Held at Fair Value on a Recurring Basis (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Significant unobservable inputs (Level 3) to determine fair value
Unrealized gain (loss) on other investments	$6,000,000	($6,000,000)
Unrealized gain (loss) on derivatives	154,000,000	-297,000,000
Unrealized gain (loss) on future policy benefits and claims	-1,300,000,000	1,800,000,000
Fair value of fixed maturity securities that were determined using non binding broker quotes	35,439,000,000	32,273,000,000
Fixed Maturity Securities Held At Fair Value [Member]
Significant unobservable inputs (Level 3) to determine fair value
Fair value of fixed maturity securities that were determined using non binding broker quotes	$1,100,000,000	$924,000,000

Summary_of_Significant_observa

Summary of Significant observable Inputs Used for Fair Value Measurements for Living Benefits Liabilities Classified as Level 3 (Detail) (Living Benefits [Member])	12 Months Ended
	Dec. 31, 2014
Minimum [Member]
Summary of significant unobservable inputs used for fair value measurements for living benefits liabilities
Fair value unobservable inputs Mortality	0.10%	[1]
Fair value unobservable inputs Lapse	0.00%
Fair value unobservable inputs wait period	0 years	[2]
Fair value unobservable inputs efficiency of benefit utilization	65.00%	[3]
Fair value unobservable inputs index Volatility	15.00%
Maximum [Member]
Summary of significant unobservable inputs used for fair value measurements for living benefits liabilities
Fair value unobservable inputs Mortality	8.00%	[1]
Fair value unobservable inputs Lapse	35.00%
Fair value unobservable inputs wait period	30 years	[2]
Fair value unobservable inputs efficiency of benefit utilization	100.00%	[3]
Fair value unobservable inputs index Volatility	25.00%
[1]	Represents the mortality for the majority of business with living benefits, with policyholders ranging from 45 to 85.
[2]	A portion of the contractholders could never use the benefit, which would extend the range to an indeterminate period.
[3]	The unobservable input is not applicable to GMABs.

Summary_of_Significant_observa1

Summary of Significant observable Inputs Used for Fair Value Measurements for Living Benefits Liabilities Classified as Level 3 (Parenthetical) (Detail) (Living Benefits [Member])	12 Months Ended
	Dec. 31, 2014
	Person
Minimum [Member]
Summary of significant unobservable inputs used for fair value measurements for living benefits liabilities
Policyholders of mortality for majority of business	45
Maximum [Member]
Summary of significant unobservable inputs used for fair value measurements for living benefits liabilities
Policyholders of mortality for majority of business	85

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value of Financial Instruments (Textual) [Abstract]
Enhancing guarantee bonus feature period	10 years
High liability value policy withdrawal period	20 years
Policy withdrawal period	1 year
Separate account expiration year	2016
Transfers from Level 1 to Level 2		$0
Level 3 [Member]
Fair Value of Financial Instruments (Textual) [Abstract]
Separate account assets	$1,700,000,000	$1,700,000,000

Summary_of_Significant_Unobser

Summary of Significant Unobservable Inputs Used for Fair Value Measurements For Indexed Universal Life Equity Indexed Products Classified as Level 3 (Detail) (Equity Index Product [Member])	12 Months Ended
	Dec. 31, 2014
Minimum [Member]
Summary Of Significant Unobservable Inputs Used For Fair Value Measurements For Equity Indexed Products [Abstract]
Fair value unobservable inputs Mortality	0.00%	[1]
Fair value unobservable inputs Lapse	0.00%
Fair value unobservable inputs index Volatility	15.00%
Maximum [Member]
Summary Of Significant Unobservable Inputs Used For Fair Value Measurements For Equity Indexed Products [Abstract]
Fair value unobservable inputs Mortality	4.00%	[1]
Fair value unobservable inputs Lapse	10.00%
Fair value unobservable inputs index Volatility	25.00%
[1]	Represents the mortality for the majority of business, with policyholders ranging from 0 to 75.

Summary_of_Significant_Unobser1

Summary of Significant Unobservable Inputs Used for Fair Value Measurements For Indexed Universal Life Equity Indexed Products Classified as Level 3 (Parenthetical) (Detail) (Equity Index Product [Member])	12 Months Ended
	Dec. 31, 2014
	Person
Minimum [Member]
Summary Of Significant Unobservable Inputs Used For Fair Value Measurements For Equity Indexed Products [Abstract]
Policyholders of mortality for majority of business	0
Maximum [Member]
Summary Of Significant Unobservable Inputs Used For Fair Value Measurements For Equity Indexed Products [Abstract]
Policyholders of mortality for majority of business	75

Financial_Instruments_Not_Carr

Financial Instruments Not Carried at Fair Value (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investments:
Mortgage loans, net of allowance	$7,270	$6,341
Policy loans	992	987
Liabilities
Short-term debt	660	278
Long-term debt	709	707
Level 2 [Member]
Liabilities
Long-term debt	1,060	997
Level 3 [Member]
Liabilities
Investment contracts	21,742	20,436
Short-term debt	660	278
Long-term debt	9	7
Mortgage loans held-for-investment [Member] | Level 3 [Member]
Investments:
Investments	7,616	6,481
Policy loans [Member] | Level 3 [Member]
Investments:
Investments	992	987
Other [Member] | Level 3 [Member]
Investments:
Investments	60	43
Fair Value [Member]
Liabilities
Investment contracts	21,742	20,436
Short-term debt	660	278
Long-term debt	1,069	1,004
Fair Value [Member] | Mortgage loans held-for-investment [Member]
Investments:
Investments	7,616	6,481
Fair Value [Member] | Policy loans [Member]
Investments:
Investments	992	987
Fair Value [Member] | Other [Member]
Investments:
Investments	60	43
Carrying Value [Member]
Liabilities
Investment contracts	23,470	21,874
Short-term debt	660	278
Long-term debt	709	707
Carrying Value [Member] | Mortgage loans held-for-investment [Member]
Investments:
Mortgage loans, net of allowance	7,270	6,341
Carrying Value [Member] | Policy loans [Member]
Investments:
Policy loans	992	987
Carrying Value [Member] | Other [Member]
Investments:
Other investments	$60	$43

Goodwill_Detail

Goodwill (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Summary of changes in the carrying value of goodwill by segment
Goodwill, beginning balance	$200	[1]	$200	[1]
Adjustments	0		0
Goodwill, ending balance	200	[1]	200	[1]
Retirement Plans [Member]
Summary of changes in the carrying value of goodwill by segment
Goodwill, beginning balance	25	[1]	25	[1]
Adjustments	0		0
Goodwill, ending balance	25	[1]	25	[1]
Individual Products and Solutions - Life and NBSG [Member]
Summary of changes in the carrying value of goodwill by segment
Goodwill, beginning balance	175	[1]	175	[1]
Adjustments	0		0
Goodwill, ending balance	$175	[1]	$175	[1]
[1]	The goodwill balances have not been previously impaired.

Goodwill_Parenthetical_Detail

Goodwill (Parenthetical) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Summary of changes in the carrying value of goodwill by segment
Impairment of goodwill	$0	$0

Summary_of_Financial_Informati

Summary of Financial Information For Closed Block (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Liabilities:
Future policyholder benefits	$1,669	$1,703
Policyholder funds and accumulated dividends	139	141
Policyholder dividends payable	22	23
Policyholder dividend obligation	152	113
Other policy obligations and liabilities	33	29
Total liabilities	2,015	2,009
Assets:
Fixed maturity securities, available-for-sale	1,336	1,320
Mortgage loans, net of allowance	272	257
Policy loans	149	157
Other assets	86	93
Total assets	1,843	1,827
Excess of reported liabilities over assets	172	182
Portion of above representing other comprehensive income:
Increase (decrease) in unrealized gain on fixed maturity securities, available-for-sale	35	-92
Adjustment to policyholder dividend obligation	-35	92
Maximum future earnings to be recognized from assets and liabilities	172	182	193	204
Available-for-Sale Securities
Fair value	1,336	1,320
Amortized cost	1,216	1,235
Shadow policyholder dividend obligation	-120	-85
Net unrealized appreciation	$0	$0

Summary_of_Closed_Block_Operat

Summary of Closed Block Operations (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Premiums	$61	$66	$73
Net investment income	93	94	98
Realized investment gains	1		1
Realized losses credited to policyholder benefit obligation	-5	-4	-5
Total revenues	150	156	167
Benefits and expenses:
Policy and contract benefits	124	123	134
Change in future policyholder benefits and interest credited to policyholder accounts	-34	-29	-27
Policyholder dividends	43	44	50
Change in policyholder dividend obligation	-1	3	-8
Other expenses	2	-2	1
Total benefits and expenses	134	139	150
Total revenues, net of benefits and expenses, before federal income tax expense	16	17	17
Federal income tax expense	6	6	6
Revenues, net of benefits and expenses and federal income tax expense	10	11	11
Maximum future earnings from assets and liabilities:
Beginning of period	182	193	204
Change during period	-10	-11	-11
End of period	$172	$182	$193

Closed_Block_Additional_Inform

Closed Block - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Closed Block (Textual) [Abstract]
Policyholder dividend obligation	$32	$28	$21

ShortTerm_Debt_Additional_Info

Short-Term Debt - Additional Information (Detail) (USD $)	12 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2014	Feb. 28, 2015	Dec. 31, 2013	31-May-11
Short Term Debt (Textual) [Abstract]
Cash equivalent maturity description	less than one year
Maximum borrowing capacity of short term debt	$350,000,000
London Interbank Offered Rate (LIBOR) [Member]
Short Term Debt (Textual) [Abstract]
Maximum borrowing capacity of short term debt	400,000,000
Revolving variable rate line of credit	1.25%
Interest rate basis on outstanding principal balances of the line of credit	LIBOR
Termination date of notes	2015-11
Renewal description	The Company may borrow, repay and re-borrow advances under the line of credit at any time prior to the termination of the note, which, among other conditions, is November 2015, subject to automatic renewal for additional one year periods unless either party terminates the agreement.
Subsequent Event [Member] | London Interbank Offered Rate (LIBOR) [Member]
Short Term Debt (Textual) [Abstract]
Short term loan repayment		200,000,000
Custodial Bank [Member]
Short Term Debt (Textual) [Abstract]
Interest rate basis on outstanding principal balances of the line of credit	One-month U.S. LIBOR		One-month U.S. LIBOR
Federal Home Loan Bank Borrowings [Member]
Short Term Debt (Textual) [Abstract]
Maximum borrowing capacity of short term debt	250,000,000
Eligible collateral for short term borrowings	8,500,000,000		4,300,000,000
Outstanding amounts	0		0
Federal Home Loan Bank capital stock purchased	25,000,000
Amounts outstanding under agreement with Federal Home Loan Bank	0		0
Revolving Credit Facility [Member]
Short Term Debt (Textual) [Abstract]
Maximum borrowing capacity of short term debt				600,000,000
Outstanding amounts	$0		0

Summary_of_Short_Term_Debt_and

Summary of Short Term Debt and Weighted Average Annual Interest Rates (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Summary of short-term debt and weighted average annual interest rates
Total short-term debt	$660	$278
Commercial paper program [Member]
Summary of short-term debt and weighted average annual interest rates
$600 million commercial paper program (0.20% and 0.24%, respectively)	264	278
Line of Credit [Member] | Revolving Credit Facility [Member]
Summary of short-term debt and weighted average annual interest rates
$400 million revolving variable rate line of credit (1.57% and 0.00%, respectively)	$396

Summary_of_Short_Term_Debt_and1

Summary of Short Term Debt and Weighted Average Annual Interest Rates (Parenthetical) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Summary of short-term debt and weighted average annual interest rates
Maximum borrowing capacity of short term debt	$350
Commercial paper program [Member]
Summary of short-term debt and weighted average annual interest rates
Maximum borrowing capacity of short term debt	600	600
Weighted average annual interest rate	0.20%	0.24%
Revolving Credit Facility [Member] | Line of Credit [Member]
Summary of short-term debt and weighted average annual interest rates
Maximum borrowing capacity of short term debt	$400	$400
Interest rate terms	Variable	Variable
Weighted average annual interest rate	1.57%	0.00%

LongTerm_Debt_Detail

Long-Term Debt (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Summary of long-term debt
Long-term debt	$709	$707
8.15% surplus note, due June 26, 2032, payable to NFS [Member]
Summary of long-term debt
Long-term debt	300	300
7.50% surplus note, due December 17, 2031, payable to NFS [Member]
Summary of long-term debt
Long-term debt	300	300
6.75% surplus note, due December 23, 2033, payable to NFS [Member]
Summary of long-term debt
Long-term debt	100	100
Other [Member]
Summary of long-term debt
Long-term debt	$9	$7

LongTerm_Debt_Parenthetical_De

Long-Term Debt (Parenthetical) (Detail)	Dec. 31, 2014
8.15% surplus note, due June 26, 2032, payable to NFS [Member]
Summary of long-term debt
Interest rate of surplus note	8.15%
7.50% surplus note, due December 17, 2031, payable to NFS [Member]
Summary of long-term debt
Interest rate of surplus note	7.50%
6.75% surplus note, due December 23, 2033, payable to NFS [Member]
Summary of long-term debt
Interest rate of surplus note	6.75%

LongTerm_Debt_Additional_infor

Long-Term Debt - Additional information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Long Term Debt (Textual) [Abstract]
Interest payments on surplus notes payable to NFS	$54	$54	$54
Variable funding surplus note, due December 31, 2040 [Member]
Long Term Debt (Textual) [Abstract]
Interest payments on surplus notes payable to NFS		$5

Summary_of_Federal_Income_Tax_

Summary of Federal Income Tax Expense (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of federal income tax (benefit) expense attributable to (loss) income before income attributable to noncontrolling interest
Current tax expense (benefit)	$5	($33)	($144)
Deferred tax (benefit) expense	-152	346	243
Total tax (benefit) expense	($147)	$313	$99

Summary_of_Federal_Income_Tax_1

Summary of Federal Income Tax Expense Attributable to Income (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of percentage computed by applying the U.S. federal income tax rate to (loss) income before federal income taxes and noncontrolling interests
Computed (expected tax (benefit) expense)	($46)	$469	$245
Dividends received deduction	-87	-112	-75
Tax credits	-53	-82	-85
Other, net	39	38	14
Total tax (benefit) expense	($147)	$313	$99
Computed (expected tax expense)	35.00%	35.00%	35.00%
Dividends received deduction, percentage	66.00%	-8.00%	-11.00%
Tax credit, percentage	41.00%	-6.00%	-12.00%
Other, net, percentage	-30.00%	2.00%	2.00%
Total percentage	112.00%	23.00%	14.00%

Federal_Income_Taxes_Additiona

Federal Income Taxes - Additional information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Federal Income Taxes (Textual) [Abstract]
Federal income tax liability	$18	$13
Federal income taxes refunded		107	95
Federal income taxes		Immaterial
Company recorded tax expense (benefit)	16	-13
Income-housing credit carryforwards description	Income-housing credit carryforwards, which expire between 2024 and 2034
Low Income-housing credit carry forwards	147
Minimum tax credit carryforwards	155
Foreign tax credit carryforwards	53
Decrease of unrecognized tax benefits	-15
IRS audit of tax return	The Company believes it is reasonably possible that the 2006 to 2010 IRS audit for the NLIC's consolidated tax returns will be effectively settled within the next 12 months and as a result the liability for unrecognized tax benefits could decrease $15 million.
Local income tax examinations year by tax authorities	2005
Income tax returns description	The IRS commenced an examination of the Company's U.S. income tax returns for the years 2009 through 2010
Maximum [Member]
Federal Income Taxes (Textual) [Abstract]
Foreign tax credit carryforwards expiring period	2024
Minimum [Member]
Federal Income Taxes (Textual) [Abstract]
Foreign tax credit carryforwards expiring period	2019
Domestic Tax Authority [Member]
Federal Income Taxes (Textual) [Abstract]
Gross federal net operating loss carryforwards	$332
Gross federal net operating loss carryforwards expiration period	2028

Summary_of_Tax_Effects_of_Temp

Summary of Tax Effects of Temporary Differences Included in Net Deferred Tax (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Deferred tax assets
Future policy benefits and claims	$1,274	$1,244
Tax credit carryforwards	355	352
Other	840	845
Gross deferred tax assets	2,469	2,441
Valuation allowance	-17	-17
Net deferred tax assets	2,452	2,424
Deferred tax liabilities
Deferred policy acquisition costs	-1,113	-1,048
Available-for-sale securities	-1,201	-821
Derivatives, including embedded derivatives	-267	-600
Other	-269	-255
Gross deferred tax liabilities	-2,850	-2,724
Net deferred tax liability	($398)	($300)

Rollforward_of_Uncertain_Tax_P

Rollforward of Uncertain Tax Positions (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Uncertain tax positions including permanent and temporary differences
Balance at beginning of period	$36	$36	$76
Additions for current year tax positions	3	2	-2
Additions for prior years tax positions			25
Reductions for prior years tax positions	-1	-2	-63
Balance at end of period	$38	$36	$36

Statutory_Financial_Informatio2

Statutory Financial Information - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statutory Financial Information (Textual) [Abstract]
Deferred tax asset, subsidiaries	$10	$10
State of Ohio insurance laws description	The State of Ohio insurance laws require Ohio-domiciled life insurance companies to seek prior regulatory approval to pay a dividend or distribute cash or other property if the fair market value thereof, together with that of other dividends or distributions made in the preceding twelve months, exceeds the greater of (1) 10% of statutory-basis policyholders' surplus as of the prior December 31 or (2) the statutory-basis net income of the insurer for the prior year.
Dividend distributions made for the period	12 months
Statutory basis policyholders surplus	10.00%
Cash dividend paid	0	0	40
NLIC paid dividend	441
Subsidiaries [Member]
Statutory Financial Information (Textual) [Abstract]
Change in deferred tax valuation	$66	$66

Statutory_Financial_Informatio3

Statutory Financial Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Parent Company [Member]
Summarize the statutory net income (loss) and statutory capital and surplus for the Company and its primary insurance subsidiary
Statutory net income (loss)	$341	$262	$764
Statutory capital and surplus	4,408	3,550	3,837
Subsidiaries [Member]
Summarize the statutory net income (loss) and statutory capital and surplus for the Company and its primary insurance subsidiary
Statutory net income (loss)	-122	-103	-54
Statutory capital and surplus	$691	$534	$311

Related_Party_Transactions_Add

Related Party Transactions - Additional information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Related Party Transactions (Textual) [Abstract]
IT service payments to NMIC and NSC	$275,000,000	$277,000,000	$283,000,000
Total account values of group annuity and life insurance contracts	3,300,000,000	3,300,000,000
Revenue from group annuity and life insurance contracts	131,000,000	137,000,000	140,000,000
Total interest credited to the account balances	109,000,000	109,000,000	113,000,000
Company made lease payments to NMIC	16,000,000	16,000,000	15,000,000
Revenues ceded to NMIC	347,000,000	291,000,000	255,000,000
Benefits, claims and expenses	217,000,000	178,000,000	167,000,000
Customer allocations to NFG funds	58,100,000,000	53,200,000,000
NFG paid to NLIC	185,000,000	163,000,000	144,000,000
Amounts on deposit with NCMC	636,000,000	228,000,000
Total commissions and fees paid	57,000,000	54,000,000	54,000,000
Notes receivable outstanding	142,000,000	146,000,000
Life insurance [Member]
Related Party Transactions (Textual) [Abstract]
Revenues ceded to NMIC	208,000,000	179,000,000	161,000,000
Nation Wide Bank [Member]
Related Party Transactions (Textual) [Abstract]
Line of credit borrowing capacity by related party	50,000,000
Line of credit outstanding	$0	$0

Contingencies_Additional_Infor

Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Defendants
Contingencies (Textual) [Abstract]
Number of defendant	200

Reinsurance_Detail

Reinsurance (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Premiums
Direct	$1,178	$1,015	$890
Assumed from other companies	0	0	0
Ceded to other companies	-347	-291	-255
Premiums	831	724	635
Life, accident and health insurance in force
Direct	241,936	228,095	216,002
Assumed from other companies	5	6	5
Ceded to other companies	-59,588	-58,310	-59,895
Life, accident and health insurance	$182,353	$169,791	$156,112

Reinsurance_Additional_informa

Reinsurance - Additional information (Detail) (Other Assets [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Other Assets [Member]
Reinsurance (Textual) [Abstract]
Amounts recoverable under reinsurance contracts	$704	$675	$684

Segment_Reporting_Additional_I

Segment Reporting - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Segment
Segment Reporting Disclosure [Line Items]
Number of reportable segments	4

Segment_Information_Detail

Segment Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues:
Policy charges	$2,065		$1,849		$1,670
Premiums	831		724		635
Net investment income	1,900		1,849		1,825
Non-operating net realized investment gains, including of other-than-temporary impairment losses	-1,051	[1]	783	[1]	427	[1]
Other revenues	-16	[2]	-88	[2]	-101	[2]
Total revenues	3,729		5,117		4,456
Benefits and expenses:
Interest credited to policyholder accounts	1,096		1,067		1,038
Benefits and claims	1,502		1,354		1,227
Amortization of DAC	207		374		575
Other expenses, net of deferrals	1,055		981		917
Total benefits and expenses	3,860		3,776		3,757
Income before federal income taxes and noncontrolling interests	-131		1,341		699
Less: non-operating net realized investment gains, including other-than-temporary impairment losses	1,051	[1]	-783	[1]	-427	[1]
Less: net loss attributable to noncontrolling interest	94		82		61
Total assets	143,524		133,445		120,170
Individual Products and Solutions - Annuity [Member]
Revenues:
Policy charges	1,175		1,021		899
Premiums	518		416		334
Net investment income	546		546		551
Other revenues	-38	[2]	-109	[2]	-124	[2]
Total revenues	2,201		1,874		1,660
Benefits and expenses:
Interest credited to policyholder accounts	370		377		375
Benefits and claims	828		694		613
Amortization of DAC	120		185		185
Other expenses, net of deferrals	300		295		266
Total benefits and expenses	1,618		1,551		1,439
Income before federal income taxes and noncontrolling interests	583		323		221
Pre-tax operating earnings (loss)	583		323		221
Total assets	72,429		68,805		58,707
Retirement Plans [Member]
Revenues:
Policy charges	107		101		94
Net investment income	750		743		736
Total revenues	857		844		830
Benefits and expenses:
Interest credited to policyholder accounts	482		473		457
Amortization of DAC	-28		-2		14
Other expenses, net of deferrals	153		151		164
Total benefits and expenses	607		622		635
Income before federal income taxes and noncontrolling interests	250		222		195
Pre-tax operating earnings (loss)	250		222		195
Total assets	30,744		29,904		27,842
Individual Products and Solutions - Life and NBSG [Member]
Revenues:
Policy charges	783		727		677
Premiums	284		282		274
Net investment income	565		544		534
Other revenues	12	[2]	6	[2]
Total revenues	1,644		1,559		1,485
Benefits and expenses:
Interest credited to policyholder accounts	231		213		199
Benefits and claims	644		636		588
Amortization of DAC	122		125		150
Other expenses, net of deferrals	348		347		307
Total benefits and expenses	1,345		1,321		1,244
Income before federal income taxes and noncontrolling interests	299		238		241
Pre-tax operating earnings (loss)	299		238		241
Total assets	29,322		27,183		25,301
Corporate and Other [Member]
Revenues:
Premiums	29		26		27
Net investment income	39		16		4
Non-operating net realized investment gains, including of other-than-temporary impairment losses	-1,051	[1]	783	[1]	427	[1]
Other revenues	10	[2]	15	[2]	23	[2]
Total revenues	-973		840		481
Benefits and expenses:
Interest credited to policyholder accounts	13		4		7
Benefits and claims	30		24		26
Amortization of DAC	-7		66		226
Other expenses, net of deferrals	254		188		180
Total benefits and expenses	290		282		439
Income before federal income taxes and noncontrolling interests	-1,263		558		42
Less: non-operating net realized investment gains, including other-than-temporary impairment losses	1,051	[1]	-783	[1]	-427	[1]
Less: adjustment to amortization of DAC and other related expenses related to net realized investment gains and losses	-11		70		243
Less: net loss attributable to noncontrolling interest	94		82		61
Pre-tax operating earnings (loss)	-129		-73		-81
Total assets	$11,029		$7,553		$8,320
[1]	Excluding operating items (trading portfolio realized gains and losses, trading portfolio valuation changes and net realized gains and losses related to hedges on GMDB contracts).
[2]	Includes operating items discussed above.

Consolidated_Summary_of_Invest1

Consolidated Summary of Investments (Detail) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Summary of Investments Other Than Investments in Related Parties
Cost	$43,227
Amount at which shown in the consolidated balance sheet	45,437
Trading assets [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	20
Fair value	21
Amount at which shown in the consolidated balance sheet	21
Policy loans [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	992
Amount at which shown in the consolidated balance sheet	992
Other investments [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	780
Amount at which shown in the consolidated balance sheet	780
Short-term investments [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	935
Amount at which shown in the consolidated balance sheet	935
Fixed maturity securities [Member] | Available-for-sale Securities [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	33,198
Fair value	35,418
Amount at which shown in the consolidated balance sheet	35,418
Fixed maturity securities [Member] | US Government Corporations and Agencies securities [Member] | Available-for-sale Securities [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	448
Fair value	527
Amount at which shown in the consolidated balance sheet	527
Fixed maturity securities [Member] | Obligations of states, political subdivisions and foreign governments [Member] | Available-for-sale Securities [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	1,966
Fair value	2,285
Amount at which shown in the consolidated balance sheet	2,285
Fixed maturity securities [Member] | Public Utility, Bonds [Member] | Available-for-sale Securities [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	2,969
Fair value	3,228
Amount at which shown in the consolidated balance sheet	3,228
Fixed maturity securities [Member] | All Other Corporate Bonds [Member] | Available-for-sale Securities [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	27,815
Fair value	29,378
Amount at which shown in the consolidated balance sheet	29,378
Equity securities [Member] | Available-for-sale Securities [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	6
Fair value	21
Amount at which shown in the consolidated balance sheet	21
Equity securities [Member] | Industrial, miscellaneous and all other [Member] | Available-for-sale Securities [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	6
Fair value	16
Amount at which shown in the consolidated balance sheet	16
Equity securities [Member] | Nonredeemable preferred stocks [Member] | Available-for-sale Securities [Member]
Summary of Investments Other Than Investments in Related Parties
Fair value	5
Amount at which shown in the consolidated balance sheet	5
Mortgage loans, net of allowance [Member]
Summary of Investments Other Than Investments in Related Parties
Cost	7,296
Amount at which shown in the consolidated balance sheet	$7,270	[1]
[1]	Difference from Column B primarily is attributable to valuation allowances due to impairments on mortgage loans (see Note 6 to the audited consolidated financial statements).

Schedule_Supplementary_Insuran

Schedule - Supplementary Insurance Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Supplementary Insurance Information
Supplementary Insurance Information, Deferred policy acquisition costs	$4,063		$3,778		$3,249
Supplementary Insurance Information, Future policy benefits, losses, claims and loss expenses	40,730		36,765		36,154
Supplementary Insurance Information, Unearned premiums	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Other policy claims and benefits payable	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Premium revenue	831		724		635
Supplementary Insurance Information, Net investment income	1,900	[2]	1,849	[2]	1,825	[2]
Supplementary Insurance Information, Benefits, claims, losses and settlement expenses	2,598		2,421		2,265
Supplementary Insurance Information, Amortization of deferred policy acquisition costs	207		374		575
Supplementary Insurance Information, Other operating expenses	1,055	[2]	981	[2]	917	[2]
Supplementary Insurance Information, Premiums written	0		0		0
IPS - Annuity [Member]
Supplementary Insurance Information
Supplementary Insurance Information, Deferred policy acquisition costs	2,495		2,214		2,110
Supplementary Insurance Information, Future policy benefits, losses, claims and loss expenses	12,619		10,985		12,214
Supplementary Insurance Information, Unearned premiums	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Other policy claims and benefits payable	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Premium revenue	518		416		334
Supplementary Insurance Information, Net investment income	546	[2]	546	[2]	551	[2]
Supplementary Insurance Information, Benefits, claims, losses and settlement expenses	1,198		1,071		988
Supplementary Insurance Information, Amortization of deferred policy acquisition costs	120		185		185
Supplementary Insurance Information, Other operating expenses	300	[2]	295	[2]	266	[2]
Supplementary Insurance Information, Premiums written	0		0		0
Retirement Plans Segment [Member]
Supplementary Insurance Information
Supplementary Insurance Information, Deferred policy acquisition costs	216		179		168
Supplementary Insurance Information, Future policy benefits, losses, claims and loss expenses	14,905		14,313		13,628
Supplementary Insurance Information, Unearned premiums	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Other policy claims and benefits payable	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Net investment income	750	[2]	743	[2]	736	[2]
Supplementary Insurance Information, Benefits, claims, losses and settlement expenses	482		473		457
Supplementary Insurance Information, Amortization of deferred policy acquisition costs	-28		-2		14
Supplementary Insurance Information, Other operating expenses	153	[2]	151	[2]	164	[2]
Supplementary Insurance Information, Premiums written	0		0		0
IPS - Life And NBSG [Member]
Supplementary Insurance Information
Supplementary Insurance Information, Deferred policy acquisition costs	1,717		1,557		1,442
Supplementary Insurance Information, Future policy benefits, losses, claims and loss expenses	10,763		10,068		9,564
Supplementary Insurance Information, Unearned premiums	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Other policy claims and benefits payable	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Premium revenue	284		282		301
Supplementary Insurance Information, Net investment income	565	[2]	544	[2]	536	[2]
Supplementary Insurance Information, Benefits, claims, losses and settlement expenses	875		849		787
Supplementary Insurance Information, Amortization of deferred policy acquisition costs	122		125		150
Supplementary Insurance Information, Other operating expenses	348	[2]	347	[2]	307	[2]
Supplementary Insurance Information, Premiums written	0		0		0
Corporate and Other Segment [Member]
Supplementary Insurance Information
Supplementary Insurance Information, Deferred policy acquisition costs	-365		-172		-471
Supplementary Insurance Information, Future policy benefits, losses, claims and loss expenses	2,443		1,399		748
Supplementary Insurance Information, Unearned premiums	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Other policy claims and benefits payable	0	[1]	0	[1]	0	[1]
Supplementary Insurance Information, Premium revenue	29		26
Supplementary Insurance Information, Net investment income	39	[2]	16	[2]	2	[2]
Supplementary Insurance Information, Benefits, claims, losses and settlement expenses	43		28		33
Supplementary Insurance Information, Amortization of deferred policy acquisition costs	-7		66		226
Supplementary Insurance Information, Other operating expenses	254	[2]	188	[2]	180	[2]
Supplementary Insurance Information, Premiums written	$0		$0		$0
[1]	Unearned premiums and other policy claims and benefits payable are included in Column C amounts.
[2]	Allocations of net investment income and certain operating expenses are based on numerous assumptions and estimates, and reported segment operating results would change if different methods were applied.

Schedule_of_Reinsurance_Detail

Schedule of Reinsurance (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount [Abstract]
Reinsurance Premiums for Insurance Companies, Product Segment, Gross amount	$1,178		$1,015		$890
Reinsurance Effect on Claims and Benefits Incurred, Amount Ceded to other companies	-347		-291		-255
Reinsurance Effect on Claims and Benefits Incurred, Amount Assumed from other companies	0		0		0
Reinsurance Effect on Claims and Benefits Incurred, Net amount	831		724		635
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of amount assumed to net	0.00%		0.00%		0.00%
Life, accident and health insurance in force [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount [Abstract]
Reinsurance Premiums for Insurance Companies, Product Segment, Gross amount	241,936		228,095		216,002
Reinsurance Effect on Claims and Benefits Incurred, Amount Ceded to other companies	-59,588		-58,310		-59,895
Reinsurance Effect on Claims and Benefits Incurred, Amount Assumed from other companies	5		6		5
Reinsurance Effect on Claims and Benefits Incurred, Net amount	182,353		169,791		156,112
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of amount assumed to net	0.00%		0.00%		0.00%
Life insurance [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount [Abstract]
Reinsurance Premiums for Insurance Companies, Product Segment, Gross amount	888	[1]	783	[1]	701	[1]
Reinsurance Effect on Claims and Benefits Incurred, Amount Ceded to other companies	-57	[1]	-59	[1]	-66	[1]
Reinsurance Effect on Claims and Benefits Incurred, Net amount	831	[1]	724	[1]	635	[1]
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of amount assumed to net	0.00%	[1]	0.00%	[1]	0.00%	[1]
Accident and health insurance [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount [Abstract]
Reinsurance Premiums for Insurance Companies, Product Segment, Gross amount	290		232		189
Reinsurance Effect on Claims and Benefits Incurred, Amount Ceded to other companies	($290)		($232)		($189)
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of amount assumed to net	0.00%		0.00%		0.00%
[1]	Primarily represents premiums from traditional life insurance and life-contingent immediate annuities and excludes deposits on investment and universal life insurance products.

Schedule_of_Valuation_and_Qual

Schedule of Valuation and Qualifying Accounts (Detail) (Allowance For Mortgage Loan [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Allowance For Mortgage Loan [Member]
Activity in the valuation allowance for mortgage loans
Valuation Allowances and Reserves, beginning Balance	$35		$44		$60
Charged to costs and expenses	-8		-4		1
Charged to other accounts	0		0		0
Deductions	1	[1]	5	[1]	17	[1]
Valuation Allowances and Reserves, Ending Balance	$26		$35		$44
[1]	Amounts generally represent payoffs, sales and recoveries.