Investments (excluding Consolidated Investment Entities)

Fixed Maturities and Equity Securities

Available-for-sale and FVO fixed maturities and equity securities were as follows as of December 31, 2017:



	Amortized Cost		Gross Unrealized Capital Gains		Gross Unrealized Capital Losses		Embedded Derivatives⁽²⁾		Fair Value		OTTI⁽³⁾⁽⁴⁾
Fixed maturities:
U.S. Treasuries	$	2,047	$	477	$	2	$	—	$	2,522	$	—
U.S. Government agencies and authorities	223		52		—		—		275		—
State, municipalities and political subdivisions	1,856		68		11		—		1,913		—
U.S. corporate public securities	20,857		2,451		50		—		23,258		—
U.S. corporate private securities	5,628		255		50		—		5,833		—
Foreign corporate public securities and foreign governments⁽¹⁾	5,241		493		18		—		5,716		—
Foreign corporate private securities⁽¹⁾	4,974		251		64		—		5,161		10

Residential mortgage-backed securities:
Agency	2,990		164		30		21		3,145		—
Non-Agency	1,257		110		4		16		1,379		16
Total Residential mortgage-backed securities	4,247		274		34		37		4,524		16
Commercial mortgage-backed securities	2,646		69		11		—		2,704		—
Other asset-backed securities	1,488		43		3		—		1,528		3

Total fixed maturities, including securities pledged	49,207		4,433		243		37		53,434		29
Less: Securities pledged	1,823		284		20		—		2,087		—
Total fixed maturities	47,384		4,149		223		37		51,347		29

Equity securities:
Common stock	272		1		—		—		273		—
Preferred stock	81		26		—		—		107		—
Total equity securities	353		27		—		—		380		—

Total fixed maturities and equity securities investments	$	47,737	$	4,176	$	223	$	37	$	51,727	$	29

⁽¹⁾ Primarily U.S. dollar denominated.

⁽²⁾ Embedded derivatives within fixed maturity securities are reported with the host investment. The changes in fair value of embedded derivatives are reported in Other net realized capital gains (losses) in the Consolidated Statements of Operations.

⁽³⁾ Represents OTTI reported as a component of Other comprehensive income (loss).

⁽⁴⁾ Amount excludes $441 of net unrealized gains on impaired available-for-sale securities.

Available-for-sale and FVO fixed maturities and equity securities were as follows as of December 31, 2016:



	Amortized Cost		Gross Unrealized Capital Gains		Gross Unrealized Capital Losses		Embedded Derivatives⁽²⁾		Fair Value		OTTI⁽³⁾⁽⁴⁾
Fixed maturities:
U.S. Treasuries	$	2,150	$	407	$	2	$	—	$	2,555	$	—
U.S. Government agencies and authorities	227		41		—		—		268		—
State, municipalities and political subdivisions	1,647		23		39		—		1,631		—
U.S. corporate public securities	21,873		1,722		178		—		23,417		6
U.S. corporate private securities	5,076		174		113		—		5,137		—
Foreign corporate public securities and foreign governments⁽¹⁾	5,161		293		69		—		5,385		—
Foreign corporate private securities⁽¹⁾	4,954		206		52		—		5,108		—

Residential mortgage-backed securities:
Agency	3,720		209		42		32		3,919		—
Non-Agency	845		97		6		23		959		25
Total Residential mortgage-backed securities	4,565		306		48		55		4,878		25
Commercial mortgage-backed securities	2,320		59		24		—		2,355		—
Other asset-backed securities	1,096		43		5		—		1,134		4

Total fixed maturities, including securities pledged	49,069		3,274		530		55		51,868		35
Less: Securities pledged	1,261		160		12		—		1,409		—
Total fixed maturities	47,808		3,114		518		55		50,459		35

Equity securities:
Common stock	152		—		—		—		152		—
Preferred stock	77		29		—		—		106		—
Total equity securities	229		29		—		—		258		—

Total fixed maturities and equity securities investments	$	48,037	$	3,143	$	518	$	55	$	50,717	$	35

⁽¹⁾ Primarily U.S. dollar denominated.

⁽³⁾ Represents OTTI reported as a component of Other comprehensive income (loss).

⁽⁴⁾ Amount excludes $408 of net unrealized gains on impaired available-for-sale securities.

The amortized cost and fair value of fixed maturities, including securities pledged, as of December 31, 2017, are shown below by contractual maturity. Actual maturities may differ from contractual maturities as securities may be restructured, called or prepaid. MBS and Other ABS are shown separately because they are not due at a single maturity date.



	Amortized Cost		Fair Value
Due to mature:
One year or less	$	988	$	1,001
After one year through five years	8,389		8,703
After five years through ten years	10,352		10,762
After ten years	21,097		24,212
Mortgage-backed securities	6,893		7,228
Other asset-backed securities	1,488		1,528
Fixed maturities, including securities pledged	$	49,207	$	53,434

The investment portfolio is monitored to maintain a diversified portfolio on an ongoing basis. Credit risk is mitigated by monitoring concentrations by issuer, sector and geographic stratification and limiting exposure to any one issuer.

As of December 31, 2017 and 2016, the Company did not have any investments in a single issuer, other than obligations of the U.S. Government and government agencies, with a carrying value in excess of 10% of the Company’s Total shareholders' equity.

The following tables set forth the composition of the U.S. and foreign corporate securities within the fixed maturity portfolio by industry category as of the dates indicated:



	Amortized Cost		Gross Unrealized Capital Gains		Gross Unrealized Capital Losses		Fair Value
December 31, 2017
Communications	$	2,587	$	341	$	4	$	2,924
Financial	5,094		487		5		5,576
Industrial and other companies	16,478		1,391		98		17,771
Energy	4,268		459		45		4,682
Utilities	6,243		607		22		6,828
Transportation	1,295		121		4		1,412
Total	$	35,965	$	3,406	$	178	$	39,193

December 31, 2016
Communications	$	2,765	$	258	$	17	$	3,006
Financial	5,143		370		28		5,485
Industrial and other companies	17,129		948		189		17,888
Energy	4,509		310		75		4,744
Utilities	5,629		397		77		5,949
Transportation	1,210		83		12		1,281
Total	$	36,385	$	2,366	$	398	$	38,353

Fixed Maturities and Equity Securities

The Company's fixed maturities and equity securities are currently designated as available-for-sale, except those accounted for using the FVO. Available-for-sale securities are reported at fair value and unrealized capital gains (losses) on these securities are recorded directly in AOCI and presented net of related changes in DAC, VOBA and Deferred income taxes. In addition, certain fixed maturities have embedded derivatives, which are reported with the host contract on the Consolidated Balance Sheets.

The Company has elected the FVO for certain of its fixed maturities to better match the measurement of assets and liabilities in the Consolidated Statements of Operations. Certain CMOs, primarily interest-only and principal-only strips, are accounted for as hybrid instruments and valued at fair value with changes in the fair value recorded in Other net realized capital gains (losses) in the Consolidated Statements of Operations.

The Company invests in various categories of CMOs, including CMOs that are not agency-backed, that are subject to different degrees of risk from changes in interest rates and defaults. The principal risks inherent in holding CMOs are prepayment and extension risks related to significant decreases and increases in interest rates resulting in the prepayment of principal from the underlying mortgages, either earlier or later than originally anticipated. As of December 31, 2017 and 2016, approximately 43.2% and 46.4%, respectively, of the Company's CMO holdings, were invested in the above mentioned types of CMOs such as interest-only or principal-only strips, that are subject to more prepayment and extension risk than traditional CMOs.

Public corporate fixed maturity securities are distinguished from private corporate fixed maturity securities based upon the manner in which they are transacted. Public corporate fixed maturity securities are issued initially through market intermediaries on a registered basis or pursuant to Rule 144A under the Securities Act of 1933 (the "Securities Act") and are traded on the secondary market through brokers acting as principal. Private corporate fixed maturity securities are originally issued by borrowers directly to investors pursuant to Section 4(a)(2) of the Securities Act, and are traded in the secondary market directly with counterparties, either without the participation of a broker or in agency transactions.

Repurchase Agreements

As of December 31, 2017 and 2016, the Company did not have any securities pledged in dollar rolls, repurchase agreement transactions or reverse repurchase agreements.

Securities Lending

As of December 31, 2017 and 2016, the fair value of loaned securities was $1,854 and $1,133, respectively, and is included in Securities pledged on the Consolidated Balance Sheets. As of December 31, 2017 and 2016, cash collateral retained by the lending agent and invested in short-term liquid assets on the Company's behalf was $1,589 and $425, respectively, and is recorded in Short-term investments under securities loan agreements, including collateral delivered on the Consolidated Balance Sheets. As of December 31, 2017 and 2016, liabilities to return collateral of $1,589 and $425, respectively, are included in Payables under securities loan agreements, including collateral held on the Consolidated Balance Sheets.

During the first quarter of 2016 under an amendment to the securities lending program, the Company began accepting non-cash collateral in the form of securities. The securities retained as collateral by the lending agent may not be sold or re-pledged, except in the event of default, and are not reflected in the Company’s Consolidated Balance Sheets. This collateral generally consists of U.S. Treasury, U.S. Government agency securities and MBS pools. As of December 31, 2017 and 2016, the fair value of securities retained as collateral by the lending agent on the Company’s behalf was $308 and $743, respectively.

The following table sets forth borrowings under securities lending transactions by class of collateral pledged for the dates indicated:



	December 31, 2017 ⁽¹⁾⁽²⁾		December 31, 2016 ⁽¹⁾⁽²⁾
U.S. Treasuries	$	587	$	701
U.S. Government agencies and authorities	5		4
U.S. corporate public securities	967		294
Short-term Investments	—		1
Foreign corporate public securities and foreign governments	338		168
Payables under securities loan agreements	$	1,897	$	1,168

⁽¹⁾ As of December 31, 2017 and 2016, borrowings under securities lending transactions include cash collateral of $1,589 and $425, respectively.

⁽²⁾ As of December 31, 2017 and 2016, borrowings under securities lending transactions include non-cash collateral of $308 and $743, respectively.

The Company's securities lending activities are conducted on an overnight basis, and all securities loaned can be recalled at any time. The Company does not offset assets and liabilities associated with its securities lending program.

Unrealized Capital Losses

Unrealized capital losses (including noncredit impairments), along with the fair value of fixed maturity securities, including securities pledged, by market sector and duration were as follows as of December 31, 2017:



	Six Months or Less Below Amortized Cost				More Than Six Months and Twelve Months or Less Below Amortized Cost				More Than Twelve Months Below Amortized Cost				Total
	Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses
U.S. Treasuries	$	166	$	2	$	—	$	—	$	15	$	—	$	181	$	2
State, municipalities and political subdivisions	356		9		6		—		35		2		397		11
U.S. corporate public securities	1,399		47		8		—		114		3		1,521		50
U.S. corporate private securities	1,068		46		—		—		84		4		1,152		50
Foreign corporate public securities and foreign governments	463		17		6		—		26		1		495		18
Foreign corporate private securities	493		64		9		—		8		—		510		64
Residential mortgage-backed	967		32		6		—		81		2		1,054		34
Commercial mortgage-backed	756		10		18		—		86		1		860		11
Other asset-backed	374		3		4		—		27		—		405		3
Total	$	6,042	$	230	$	57	$	—	$	476	$	13	$	6,575	$	243



	Six Months or Less Below Amortized Cost				More Than Six Months and Twelve Months or Less Below Amortized Cost				More Than Twelve Months Below Amortized Cost				Total
	Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses
U.S. Treasuries	$	209	$	2	$	—	$	—	$	—	$	—	$	209	$	2
State, municipalities and political subdivisions	945		38		2		—		49		1		996		39
U.S. corporate public securities	4,568		175		14		—		112		3		4,694		178
U.S. corporate private securities	1,596		109		10		1		87		3		1,693		113
Foreign corporate public securities and foreign governments	1,274		63		6		2		139		4		1,419		69
Foreign corporate private securities	1,026		52		—		—		—		—		1,026		52
Residential mortgage-backed	1,389		47		1		—		21		1		1,411		48
Commercial mortgage-backed	680		22		—		—		23		2		703		24
Other asset-backed	430		5		—		—		—		—		430		5
Total	$	12,117	$	513	$	33	$	3	$	431	$	14	$	12,581	$	530

Of the unrealized capital losses aged more than twelve months, the average market value of the related fixed maturities was 97.3% and 96.9% of the average book value as of December 31, 2017 and 2016, respectively.

Unrealized capital losses (including noncredit impairments) in fixed maturities, including securities pledged, for instances in which fair value declined below amortized cost by greater than or less than 20% for consecutive months as indicated in the tables below, were as follows as of the dates indicated:



	Amortized Cost				Unrealized Capital Losses				Number of Securities
	< 20%		> 20%		< 20%		> 20%		< 20%	> 20%
December 31, 2017
Six months or less below amortized cost	$	6,126	$	196	$	148	$	82	1,098	38
More than six months and twelve months or less below amortized cost	48		—		1		—		14	—
More than twelve months below amortized cost	448		—		12		—		87	—
Total	$	6,622	$	196	$	161	$	82	1,199	38

December 31, 2016
Six months or less below amortized cost	$	12,536	$	195	$	466	$	53	1,694	63
More than six months and twelve months or less below amortized cost	45		—		2		—		13	—
More than twelve months below amortized cost	335		—		9		—		38	1
Total	$	12,916	$	195	$	477	$	53	1,745	64

Unrealized capital losses (including noncredit impairments) in fixed maturities, including securities pledged, by market sector for instances in which fair value declined below amortized cost by greater than or less than 20% were as follows as of the dates indicated:



	Amortized Cost				Unrealized Capital Losses				Number of Securities
	< 20%		> 20%		< 20%		> 20%		< 20%	> 20%
December 31, 2017
U.S. Treasuries	$	183	$	—	$	2	$	—	29	—
State, municipalities and political subdivisions	408		—		11		—		103	—
U.S. corporate public securities	1,553		18		45		5		232	2
U.S. corporate private securities	1,129		73		28		22		73	2
Foreign corporate public securities and foreign governments	506		7		16		2		84	1
Foreign corporate private securities	490		84		16		48		35	6
Residential mortgage-backed	1,075		13		29		5		334	25
Commercial mortgage-backed	871		—		11		—		164	—
Other asset-backed	407		1		3		—		145	2
Total	$	6,622	$	196	$	161	$	82	1,199	38

December 31, 2016
U.S. Treasuries	$	211	$	—	$	2	$	—	25	—
State, municipalities and political subdivisions	1,034		1		39		—		198	1
U.S. corporate public securities	4,811		61		163		15		547	17
U.S. corporate private securities	1,699		107		84		29		111	3
Foreign corporate public securities and foreign governments	1,471		17		64		5		186	10
Foreign corporate private securities	1,078		—		52		—		64	2
Residential mortgage-backed	1,452		7		45		3		365	28
Commercial mortgage-backed	727		—		24		—		124	2
Other asset-backed	433		2		4		1		125	1
Total	$	12,916	$	195	$	477	$	53	1,745	64

The following tables summarize loan-to-value, credit enhancement and fixed floating rate details for RMBS and Other ABS in a gross unrealized loss position as of the dates indicated:



	Loan-to-Value Ratio
	Amortized Cost				Unrealized Capital Losses
December 31, 2017	< 20%		> 20%		< 20%		> 20%
RMBS and Other ABS⁽¹⁾
Non-agency RMBS > 100%	$	—	$	—	$	—	$	—
Non-agency RMBS > 90% - 100%	—		—		—		—
Non-agency RMBS 80% - 90%	13		—		—		—
Non-agency RMBS < 80%	211		1		4		—
Agency RMBS	878		12		26		4
Other ABS (Non-RMBS)	380		1		2		1
Total RMBS and Other ABS	$	1,482	$	14	$	32	$	5

	Credit Enhancement Percentage
	Amortized Cost				Unrealized Capital Losses
December 31, 2017	< 20%		> 20%		< 20%		> 20%
RMBS and Other ABS⁽¹⁾
Non-agency RMBS 10% +	$	162	$	—	$	2	$	—
Non-agency RMBS > 5% - 10%	11		—		—		—
Non-agency RMBS > 0% - 5%	25		1		1		—
Non-agency RMBS 0%	26		—		1		—
Agency RMBS	878		12		26		4
Other ABS (Non-RMBS)	380		1		2		1
Total RMBS and Other ABS	$	1,482	$	14	$	32	$	5

	Fixed Rate/Floating Rate
	Amortized Cost				Unrealized Capital Losses
December 31, 2017	< 20%		> 20%		< 20%		> 20%
Fixed Rate	$	1,104	$	6	$	20	$	2
Floating Rate	378		8		12		3
Total	$	1,482	$	14	$	32	$	5

⁽¹⁾ For purposes of this table, subprime mortgages are included in Non-agency RMBS categories.



	Loan-to-Value Ratio
	Amortized Cost				Unrealized Capital Losses
December 31, 2016	< 20%		> 20%		< 20%		> 20%
RMBS and Other ABS⁽¹⁾
Non-agency RMBS > 100%	$	—	$	—	$	—	$	—
Non-agency RMBS > 90% - 100%	—		—		—		—
Non-agency RMBS 80% - 90%	5		—		—		—
Non-agency RMBS < 80%	149		4		8		1
Agency RMBS	1,347		3		39		3
Other ABS (Non-RMBS)	384		2		2		—
Total RMBS and Other ABS	$	1,885	$	9	$	49	$	4

	Credit Enhancement Percentage
	Amortized Cost				Unrealized Capital Losses
December 31, 2016	< 20%		> 20%		< 20%		> 20%
RMBS and Other ABS⁽¹⁾
Non-agency RMBS 10% +	$	92	$	—	$	5	$	—
Non-agency RMBS > 5% - 10%	9		—		—		—
Non-agency RMBS > 0% - 5%	25		—		2		—
Non-agency RMBS 0%	28		4		1		1
Agency RMBS	1,347		3		39		3
Other ABS (Non-RMBS)	384		2		2		—
Total RMBS and Other ABS	$	1,885	$	9	$	49	$	4

	Fixed Rate/Floating Rate
	Amortized Cost				Unrealized Capital Losses
December 31, 2016	< 20%		> 20%		< 20%		> 20%
Fixed Rate	$	1,393	$	3	$	34	$	2
Floating Rate	492		6		15		2
Total	$	1,885	$	9	$	49	$	4

⁽¹⁾ For purposes of this table, subprime mortgages are included in Non-agency RMBS categories.

Investments with fair values less than amortized cost are included in the Company's other-than-temporary impairments analysis. Impairments were recognized as disclosed in the "Evaluating Securities for Other-Than-Temporary Impairments" section below. The Company evaluates non-agency RMBS and ABS for "other-than-temporary impairments" each quarter based on actual and projected cash flows, after considering the quality and updated loan-to-value ratios reflecting current home prices of underlying collateral, forecasted loss severity, the payment priority within the tranche structure of the security and amount of any credit enhancements. The Company's assessment of current levels of cash flows compared to estimated cash flows at the time the securities were acquired (typically pre-2008) indicates the amount and the pace of projected cash flows from the underlying collateral has generally been lower and slower, respectively. However, since cash flows are typically projected at a trust level, the impairment review incorporates the security's position within the trust structure as well as credit enhancement remaining in the trust to determine whether an impairment is warranted. Therefore, while lower and slower cash flows will impact the trust, the effect on the valuation of a particular security within the trust will also be dependent upon the trust structure. Where the assessment continues to project full recovery of principal and interest on schedule, the Company has not recorded an impairment. Based on this analysis, the Company determined that the remaining investments in an unrealized loss position were not other-than-temporarily impaired and therefore no further other-than-temporary impairment was necessary.

Troubled Debt Restructuring

The Company invests in high quality, well performing portfolios of commercial mortgage loans and private placements. Under certain circumstances, modifications are granted to these contracts. Each modification is evaluated as to whether a troubled debt restructuring has occurred. A modification is a troubled debt restructuring when the borrower is in financial difficulty and the creditor makes concessions. Generally, the types of concessions may include reducing the face amount or maturity amount of the debt as originally stated, reducing the contractual interest rate, extending the maturity date at an interest rate lower than current market interest rates and/or reducing accrued interest. The Company considers the amount, timing and extent of the concession granted in determining any impairment or changes in the specific valuation allowance recorded in connection with the troubled debt restructuring. A valuation allowance may have been recorded prior to the quarter when the loan is modified in a troubled debt restructuring. Accordingly, the carrying value (net of the specific valuation allowance) before and after modification through a troubled debt restructuring may not change significantly, or may increase if the expected recovery is higher than the pre-modification recovery assessment. For the year ended December 31, 2017, the Company did not have any new commercial mortgage loan troubled debt restructuring and had one private placement troubled debt restructuring with a pre-modification and post-modification carrying value of $22. For the year ended December 31, 2016, the Company had no new troubled debt restructurings for commercial mortgage loans or private placement bonds.

As of December 31, 2017, the Company held no commercial mortgage troubled debt restructured loans.

As of December 31, 2017 and 2016, the Company did not have any commercial mortgage loans or private placements modified in a troubled debt restructuring with a subsequent payment default.

Mortgage Loans on Real Estate

The Company's mortgage loans on real estate are all commercial mortgage loans held for investment, which are reported at amortized cost, less impairment write-downs and allowance for losses. The Company diversifies its commercial mortgage loan portfolio by geographic region and property type to reduce concentration risk. The Company manages risk when originating commercial mortgage loans by generally lending only up to 75% of the estimated fair value of the underlying real estate. Subsequently, the Company continuously evaluates mortgage loans based on relevant current information including a review of loan-specific credit quality, property characteristics and market trends. Loan performance is monitored on a loan specific basis through the review of submitted appraisals, operating statements, rent revenues and annual inspection reports, among other items. This review ensures properties are performing at a consistent and acceptable level to secure the debt. The components to evaluate debt service coverage are received and reviewed at least annually to determine the level of risk.

The following table summarizes the Company's investment in mortgage loans as of the dates indicated:



	December 31, 2017								December 31, 2016
	Impaired		Non Impaired			Total			Impaired		Non Impaired			Total
Commercial mortgage loans	$	4	$	8,685		$	8,689		$	5	$	8,001		$	8,006
Collective valuation allowance for losses	N/A		(3		)	(3		)	N/A		(3		)	(3		)
Total net commercial mortgage loans	$	4	$	8,682		$	8,686		$	5	$	7,998		$	8,003

N/A - Not Applicable

There were no impairments taken on the mortgage loan portfolio for the years ended December 31, 2017 and 2016.

The following table summarizes the activity in the allowance for losses for commercial mortgage loans for the periods indicated:



	December 31, 2017		December 31, 2016
Collective valuation allowance for losses, balance at January 1	$	3	$	3
Addition to (reduction of) allowance for losses	—		—
Collective valuation allowance for losses, end of period	$	3	$	3

The carrying values and unpaid principal balances of impaired mortgage loans were as follows as of the dates indicated:



	December 31, 2017		December 31, 2016
Impaired loans without allowances for losses	$	4	$	5
Less: Allowances for losses on impaired loans	—		—
Impaired loans, net	$	4	$	5
Unpaid principal balance of impaired loans	$	6	$	6

For the years ended December 31, 2017 and 2016, the Company did not have any impaired loans with allowances for losses.

The Company defines delinquent mortgage loans consistent with industry practice as 60 days past due. The Company's policy is to recognize interest income until a loan becomes 90 days delinquent or foreclosure proceedings are commenced, at which point interest accrual is discontinued. Interest accrual is not resumed until the loan is brought current.

There were no mortgage loans in the Company's portfolio in process of foreclosure as of December 31, 2017 and 2016.

There were no loans 30 days or less in arrears, with respect to principal and interest as of December 31, 2017 and 2016.

The following table presents information on the average investment during the period in impaired loans and interest income recognized on impaired and troubled debt restructured loans for the periods indicated:



	Year Ended December 31,
	2017		2016		2015
Impaired loans, average investment during the period (amortized cost)⁽¹⁾	$	4	$	11	$	36
Interest income recognized on impaired loans, on an accrual basis⁽¹⁾	—		—		2
Interest income recognized on impaired loans, on a cash basis⁽¹⁾	—		—		2
Interest income recognized on troubled debt restructured loans, on an accrual basis	—		—		2

⁽¹⁾ Includes amounts for Troubled debt restructured loans.

Loan-to-value ("LTV") and debt service coverage ("DSC") ratios are measures commonly used to assess the risk and quality of mortgage loans. The LTV ratio, calculated at time of origination, is expressed as a percentage of the amount of the loan relative to the value of the underlying property. A LTV ratio in excess of 100% indicates the unpaid loan amount exceeds the underlying collateral. The DSC ratio, based upon the most recently received financial statements, is expressed as a percentage of the amount of a property’s net income to its debt service payments. A DSC ratio of less than 1.0 indicates that property’s operations do not generate sufficient income to cover debt payments. These ratios are utilized as part of the review process described above.

The following table presents the LTV ratios as of the dates indicated:



	December 31, 2017⁽¹⁾		December 31, 2016⁽¹⁾
Loan-to-Value Ratio:
0% - 50%	$	849	$	950
>50% - 60%	2,125		1,976
>60% - 70%	5,144		4,544
>70% - 80%	551		523
>80% and above	20		13
Total Commercial mortgage loans	$	8,689	$	8,006

⁽¹⁾Balances do not include collective valuation allowance for losses.

The following table presents the DSC ratios as of the dates indicated:



	December 31, 2017⁽¹⁾		December 31, 2016⁽¹⁾
Debt Service Coverage Ratio:
Greater than 1.5x	$	7,013	$	6,421
>1.25x - 1.5x	655		824
>1.0x - 1.25x	893		597
Less than 1.0x	105		105
Commercial mortgage loans secured by land or construction loans	23		59
Total Commercial mortgage loans	$	8,689	$	8,006

⁽¹⁾Balances do not include collective valuation allowance for losses.

Properties collateralizing mortgage loans are geographically dispersed throughout the United States, as well as diversified by property type, as reflected in the following tables as of the dates indicated:



	December 31, 2017⁽¹⁾			December 31, 2016⁽¹⁾
	Gross Carrying Value		% of Total	Gross Carrying Value		% of Total
Commercial Mortgage Loans by U.S. Region:
Pacific	$	2,024	23.4	$	2,055	25.7	%
South Atlantic	1,716		19.7	1,703		21.3	%
Middle Atlantic	1,612		18.5	1,169		14.6	%
West South Central	959		11.0	801		10.0	%
Mountain	859		9.9	729		9.1	%
East North Central	884		10.2	885		11.1	%
New England	161		1.8	170		2.1	%
West North Central	391		4.5	371		4.6	%
East South Central	83		1.0	123		1.5	%
Total Commercial mortgage loans	$	8,689	100.0	$	8,006	100.0	%

⁽¹⁾ Balances do not include collective valuation allowance for losses.



	December 31, 2017⁽¹⁾			December 31, 2016⁽¹⁾
	Gross Carrying Value		% of Total	Gross Carrying Value		% of Total
Commercial Mortgage Loans by Property Type:
Retail	$	2,587	29.7	$	2,607	32.6	%
Industrial	2,108		24.3	1,708		21.3	%
Apartments	1,849		21.3	1,620		20.2	%
Office	1,384		15.9	1,267		15.8	%
Hotel/Motel	309		3.6	332		4.2	%
Other	364		4.2	388		4.9	%
Mixed Use	88		1.0	84		1.0	%
Total Commercial mortgage loans	$	8,689	100.0	$	8,006	100.0	%

⁽¹⁾ Balances do not include collective valuation allowance for losses.

The following table presents mortgages by year of origination as of the dates indicated:



	December 31, 2017⁽¹⁾		December 31, 2016⁽¹⁾
Year of Origination:
2017	$	1,525	$	—
2016	1,428		1,434
2015	1,250		1,286
2014	1,303		1,333
2013	1,287		1,371
2012	818		1,084
2011 and prior	1,078		1,498
Total Commercial mortgage loans	$	8,689	$	8,006

⁽¹⁾ Balances do not include collective valuation allowance for losses.

Evaluating Securities for Other-Than-Temporary Impairments

The Company performs a regular evaluation, on a security-by-security basis, of its available-for-sale securities holdings, including fixed maturity securities and equity securities in accordance with its impairment policy in order to evaluate whether such investments are other-than-temporarily impaired.

The following table identifies the Company's credit-related and intent-related impairments included in the Consolidated Statements of Operations, excluding impairments included in Other comprehensive income (loss) by type for the periods indicated:



	Year Ended December 31,
	2017			2016			2015
	Impairment		No. of Securities	Impairment		No. of Securities	Impairment		No. of Securities
State, municipalities and political subdivisions	1		3	—		2	—		—
U.S. corporate public securities	1		3	8		3	29		24
Foreign corporate public securities and foreign governments⁽¹⁾	2		3	17		4	44		12
Foreign corporate private securities⁽¹⁾	15		2	2		2	1		1
Residential mortgage-backed	2		47	7		80	6		59
Other	—		3	—		1	3		5
Total	$	21	61	$	34	92	$	83	101

⁽¹⁾ Primarily U.S. dollar denominated.

The above tables include $19, $8 and $8 of write-downs related to credit impairments for the years ended December 31, 2017, 2016 and 2015, respectively, in Other-than-temporary impairments, which are recognized in the Consolidated Statements of Operations. The remaining $2, $26 and $75 in write-downs for the years ended December 31, 2017, 2016 and 2015, respectively, are related to intent impairments.

The following table summarizes these intent impairments, which are also recognized in earnings, by type for the periods indicated:



	Year Ended December 31,
	2017			2016			2015
	Impairment		No. of Securities	Impairment		No. of Securities	Impairment		No. of Securities
U.S. corporate public securities	1		3	7		2	29		23
Foreign corporate public securities and foreign governments⁽¹⁾	—		—	16		3	43		11
Residential mortgage-backed	1		12	3		20	2		11
Other	—		3	—		1	1		2
Total	$	2	18	$	26	26	$	75	47

The Company may sell securities during the period in which fair value has declined below amortized cost for fixed maturities or cost for equity securities. In certain situations, new factors, including changes in the business environment, can change the Company’s previous intent to continue holding a security. Accordingly, these factors may lead the Company to record additional intent related capital losses.

The following table identifies the amount of credit impairments on fixed maturities for which a portion of the OTTI loss was recognized in Other comprehensive income (loss) and the corresponding changes in such amounts for the periods indicated:



	Year Ended December 31,
	2017		2016		2015
Balance at January 1	$	33	$	46	$	53
Additional credit impairments:
On securities not previously impaired	15		—		—
On securities previously impaired	1		2		4
Reductions:
Increase in cash flows	1		—		1
Securities sold, matured, prepaid or paid down	8		15		10
Balance at December 31	$	40	$	33	$	46

Net Investment Income

The following table summarizes Net investment income for the periods indicated:



	Year Ended December 31,
	2017		2016		2015
Fixed maturities	$	2,698	$	2,860	$	2,851
Equity securities, available-for-sale	9		11		9
Mortgage loans on real estate	388		372		394
Policy loans	100		108		110
Short-term investments and cash equivalents	10		5		3
Other	145		62		37
Gross investment income	3,350		3,418		3,404
Less: investment expenses	56		64		61
Net investment income	$	3,294	$	3,354	$	3,343

As of December 31, 2017 and 2016, the Company had $5 and $8, respectively, of investments in fixed maturities that did not produce net investment income. Fixed maturities are moved to a non-accrual status when the investment defaults.

Interest income on fixed maturities is recorded when earned using an effective yield method, giving effect to amortization of premiums and accretion of discounts. Such interest income is recorded in Net investment income in the Consolidated Statements of Operations.

Net Realized Capital Gains (Losses)

Net realized capital gains (losses) comprise the difference between the amortized cost of investments and proceeds from sale and redemption, as well as losses incurred due to the credit-related and intent-related other-than-temporary impairment of investments. Realized investment gains and losses are also primarily generated from changes in fair value of embedded derivatives within products and fixed maturities, changes in fair value of fixed maturities recorded at FVO and changes in fair value including accruals on derivative instruments, except for effective cash flow hedges. The cost of the investments on disposal is generally determined based on FIFO methodology.

Net realized capital gains (losses) were as follows for the periods indicated:



	Year Ended December 31,
	2017			2016			2015
Fixed maturities, available-for-sale, including securities pledged	$	7		$	(98	)	$	(90	)
Fixed maturities, at fair value option	(282		)	(296		)	(336		)
Equity securities, available-for-sale	(1		)	1			(4		)
Derivatives	98			32			(68		)
Embedded derivatives - fixed maturities	(18		)	(19		)	(16		)
Guaranteed benefit derivatives	(22		)	9			(46		)
Other investments	(9		)	8			—
Net realized capital gains (losses)	$	(227	)	$	(363	)	$	(560	)
After-tax net realized capital gains (losses)	$	(120	)	$	(268	)	$	(370	)

Proceeds from the sale of fixed maturities and equity securities, available-for-sale and the related gross realized gains and losses, before tax, were as follows for the periods indicated:



	Year Ended December 31,
	2017		2016		2015
Proceeds on sales	$	4,905	$	4,742	$	4,932
Gross gains	93		91		91
Gross losses	56		157		104