Fixed maturities include bonds, ABS, redeemable preferred stock and certain non-redeemable preferred securities. Equity securities include mutual funds, common stock, non-redeemable preferred stock and required regulatory investments. We classify fixed maturities as either available-for-sale or trading at the time of the purchase and, accordingly, carry them at fair value. Equity securities are also carried at fair value. See Note 11, Fair Value Measurements, for methodologies related to the determination of fair value. Unrealized gains and losses related to fixed maturities, available-for-sale, excluding those in fair value hedging relationships, are reflected in stockholders' equity, net of adjustments associated with DAC and related actuarial balances, derivatives in cash flow hedge relationships and applicable income taxes. Mark-to-market adjustments on equity securities, unrealized gains and losses related to hedged portions of fixed maturities, available-for-sale in fair value hedging relationships prior to 2019 and mark-to-market adjustments on certain fixed maturities, trading are reflected in net realized capital gains (losses). Beginning in 2019, unrealized gains and losses related to hedged portions of fixed maturities, available-for-sale in fair value hedging relationships are reflected in net investment income. Mark-to-market adjustments related to certain securities carried at fair value with an investment objective to realize economic value through mark-to-market changes are reflected in net investment income.

The amortized cost of fixed maturities includes cost adjusted for amortization of premiums and discounts, computed using the interest method. The amortized cost of fixed maturities, available-for-sale is adjusted for changes in fair value of the hedged portions of securities in fair value hedging relationships and declines in value that are other than temporary. Impairments in value deemed to be other than temporary are primarily reported in net income as a component of net realized capital gains (losses), with noncredit impairment losses for certain fixed maturities, available-for-sale reported in other comprehensive income (“OCI”). For loan-backed and structured securities, we recognize income using a constant effective yield based on currently anticipated cash flows.

The amortized cost, gross unrealized gains and losses, other-than-temporary impairments in AOCI and fair value of available-for-sale securities were as follows:

The amortized cost and fair value of fixed maturities, available-for-sale as of June 30, 2019, by expected maturity, were as follows:

Actual maturities may differ because borrowers may have the right to call or prepay obligations. Our portfolio is diversified by industry, issuer and asset class. Credit concentrations are managed to established limits.

Net realized capital gains and losses on sales of investments are determined on the basis of specific identification. In general, in addition to realized capital gains and losses on investment sales and periodic settlements on derivatives not designated as hedges, we report gains and losses related to the following in net realized capital gains (losses): other-than-

temporary impairments of securities and subsequent realized recoveries, mark-to-market adjustments on equity securities, mark-to-market adjustments on certain fixed maturities, trading, mark-to-market adjustments on sponsored investment funds, mark-to-market adjustments on derivatives not designated as hedges, changes in the mortgage loan valuation allowance provision, impairments of real estate held for investment and impairments on equity method investments. Investment gains and losses on sales of certain real estate held for sale due to investment strategy and mark-to-market adjustments on certain securities carried at fair value with an investment objective to realize economic value through mark-to-market changes are reported as net investment income and are excluded from net realized capital gains (losses). The major components of net realized capital gains (losses) on investments were as follows:

Proceeds from sales of investments (excluding call and maturity proceeds) in fixed maturities, available-for-sale were $1,028.0 million and $525.9 million for the three months ended June 30, 2019 and 2018, and $1,191.0 million and $1,737.7 million for the six months ended June 30, 2019 and 2018, respectively.

We have a process in place to identify fixed maturity securities that could potentially have an impairment that is other than temporary. This process involves monitoring market events that could impact issuers’ credit ratings, business climate, management changes, litigation and government actions and other similar factors. This process also involves monitoring late payments, pricing levels, downgrades by rating agencies, key financial ratios, financial statements, revenue forecasts and cash flow projections as indicators of credit issues.

Each reporting period, all securities are reviewed to determine whether an other-than-temporary decline in value exists and whether losses should be recognized. We consider relevant facts and circumstances in evaluating whether a credit or interest rate related impairment of a security is other than temporary. Relevant facts and circumstances considered include: (1) the extent and length of time the fair value has been below cost; (2) the reasons for the decline in value; (3) the financial

position and access to capital of the issuer, including the current and future impact of any specific events; (4) for structured securities, the adequacy of the expected cash flows and (5) our intent to sell a security or whether it is more likely than not we will be required to sell the security before the recovery of its amortized cost which, in some cases, may extend to maturity. To the extent we determine a security is deemed to be other than temporarily impaired, an impairment loss is recognized.

The way in which impairment losses on fixed maturities are recognized in the financial statements is dependent on the facts and circumstances related to the specific security. If we intend to sell a security or it is more likely than not that we would be required to sell a security before the recovery of its amortized cost, we recognize an other-than-temporary impairment in net income for the difference between amortized cost and fair value. If we do not expect to recover the amortized cost basis, we do not plan to sell the security and if it is not more likely than not that we would be required to sell a security before the recovery of its amortized cost, the recognition of the other-than-temporary impairment is bifurcated. We recognize the credit loss portion in net income and the noncredit loss portion in OCI (“bifurcated OTTI”).

Total other-than-temporary impairment losses, net of recoveries from the sale of previously impaired fixed maturities, available-for-sale, were as follows:

We estimate the amount of the credit loss component of a fixed maturity security impairment as the difference between amortized cost and the present value of the expected cash flows of the security. The present value is determined using the best estimate cash flows discounted at the effective interest rate implicit to the security at the date of purchase or the current yield to accrete an asset-backed or floating rate security. The methodology and assumptions for establishing the best estimate cash flows vary depending on the type of security. The ABS cash flow estimates are based on security specific facts and circumstances that may include collateral characteristics, expectations of delinquency and default rates, loss severity and prepayment speeds and structural support, including subordination and guarantees. The corporate security cash flow estimates are derived from scenario-based outcomes of expected corporate restructurings or liquidations using bond specific facts and circumstances including timing, security interests and loss severity.

The following table provides a rollforward of accumulated credit losses for fixed maturities with bifurcated credit losses. The purpose of the table is to provide detail of (1) additions to the bifurcated credit loss amounts recognized in net realized capital gains (losses) during the period and (2) decrements for previously recognized bifurcated credit losses where the loss is no longer bifurcated and/or there has been a positive change in expected cash flows or accretion of the bifurcated credit loss amount.


	For the three months ended				For the six months ended
	June 30,				June 30,
	2019		2018		2019		2018
	(in millions)
Beginning balance	$	(102.3)	$	(129.2)	$	(117.5)	$	(124.3)
Credit losses for which an other-than-temporary impairment was not previously recognized		(0.8)		(5.5)		(2.8)		(10.1)
Credit losses for which an other-than-temporary impairment was previously recognized		(4.6)		(1.9)		(8.9)		(11.7)
Reduction for credit losses previously recognized on fixed maturities now sold, paid down or intended to be sold		8.0		2.7		28.4		10.0
Net reduction (increase) for positive changes in cash flows expected to be collected and amortization (1)		(0.6)		2.8		0.5		5.0
Ending balance	$	(100.3)	$	(131.1)	$	(100.3)	$	(131.1)

(1)	Amounts are recognized in net investment income.

Gross Unrealized Losses for Available-for-Sale Securities

For available-for-sale securities with unrealized losses, including other-than-temporary impairment losses reported in OCI, the gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position were as follows:

June 30, 2019

Less than

Greater than or

twelve months

equal to twelve months

Total

Gross

Fair

unrealized

Fair

unrealized

Fair

unrealized

value

losses

value

losses

value

losses

(in millions)

Fixed maturities, available-for-sale:

U.S. government and agencies

5.7

—

160.8

3.9

166.5

3.9

Non-U.S. governments

13.2

0.2

47.9

2.3

61.1

2.5

States and political subdivisions

2.3

—

509.8

5.6

512.1

5.6

Corporate

579.1

9.7

2,556.0

71.6

3,135.1

81.3

Residential mortgage-backed pass-through securities

1.0

—

747.4

8.8

748.4

8.8

Commercial mortgage-backed securities

127.3

2.1

625.6

19.0

752.9

21.1

Collateralized debt obligations (1)

975.5

2.7

1,063.9

10.9

2,039.4

13.6

Other debt obligations

110.9

0.5

1,677.0

13.9

1,787.9

14.4

Total fixed maturities, available-for-sale

1,815.0

15.2

7,388.4

136.0

9,203.4

151.2

(1)	Primarily consists of collateralized loan obligations backed by secured corporate loans.

Of the total amounts, Principal Life’s consolidated portfolio represented $9,072.5 million in available-for-sale fixed maturities with gross unrealized losses of $148.1 million. Of the available-for-sale fixed maturities within Principal Life's consolidated portfolio in a gross unrealized loss position, 94% were investment grade (rated AAA through BBB-) with an average price of 98 (carrying value/amortized cost) as of June 30, 2019. Gross unrealized losses in our fixed maturities portfolio decreased during the six months ended June 30, 2019, primarily due to a decrease in interest rates and tightening of credit spreads.

For those securities that had been in a continuous unrealized loss position for less than twelve months, Principal Life's consolidated portfolio held 177 securities with a carrying value of $1,768.2 million and unrealized losses of $14.3

million reflecting an average price of 99 as of June 30, 2019. Of this portfolio, 84% was investment grade (rated AAA through BBB-) as of June 30, 2019, with associated unrealized losses of $8.8 million. The unrealized losses on these securities can primarily be attributed to changes in market interest rates and changes in credit spreads since the securities were acquired.

For those securities that had been in a continuous unrealized loss position greater than or equal to twelve months, Principal Life’s consolidated portfolio held 1,081 securities with a carrying value of $7,304.3 million and unrealized losses of $133.8 million. The average credit rating of this portfolio was AA- with an average price of 98 as of June 30, 2019. Of the $133.8 million in unrealized losses, the corporate sector accounts for $69.7 million in unrealized losses with an average price of 97 and an average credit rating of BBB+. The remaining unrealized losses also include $18.8 million within the commercial mortgage-backed securities sector with an average price of 97 and an average credit rating of AA+. The unrealized losses on these securities can primarily be attributed to changes in market interest rates and changes in credit spreads since the securities were acquired.

Because we expected to recover our amortized cost, it was not our intent to sell the fixed maturity available-for-sale securities with unrealized losses and it was not more likely than not that we would be required to sell these securities before recovery of the amortized cost, which may be at maturity, we did not consider these investments to be other-than-temporarily impaired as of June 30, 2019.


	December 31, 2018
	Less than				Greater than or
	twelve months				equal to twelve months				Total
			Gross				Gross				Gross
	Fair		unrealized		Fair		unrealized		Fair		unrealized
	value		losses		value		losses		value		losses
	(in millions)
Fixed maturities, available-for-sale:
U.S. government and agencies	$	101.8	$	1.6	$	500.3	$	15.4	$	602.1	$	17.0
Non-U.S. governments		210.2		4.7		191.5		9.9		401.7		14.6
States and political subdivisions		1,359.9		33.9		1,590.3		61.4		2,950.2		95.3
Corporate		13,198.4		476.0		6,865.0		369.2		20,063.4		845.2
Residential mortgage-backed pass-through securities		236.7		1.0		1,410.2		48.8		1,646.9		49.8
Commercial mortgage-backed securities		790.3		11.6		2,223.2		83.0		3,013.5		94.6
Collateralized debt obligations (1)		2,233.3		24.0		162.6		6.5		2,395.9		30.5
Other debt obligations		985.5		4.9		3,665.1		77.8		4,650.6		82.7
Total fixed maturities, available-for-sale	$	19,116.1	$	557.7	$	16,608.2	$	672.0	$	35,724.3	$	1,229.7

(1)	Primarily consists of collateralized loan obligations backed by secured corporate loans.

Of the total amounts, Principal Life’s consolidated portfolio represented $35,051.9 million in available-for-sale fixed maturities with gross unrealized losses of $1,202.9 million. Of the available-for-sale fixed maturities within Principal Life's consolidated portfolio in a gross unrealized loss position, 95% were investment grade (rated AAA through BBB-) with an average price of 97 (carrying value/amortized cost) as of December 31, 2018. Gross unrealized losses in our fixed maturities portfolio increased during the year ended December 31, 2018, primarily due to widening of credit spreads and an increase in interest rates.

For those securities that had been in a continuous unrealized loss position for less than twelve months, Principal Life's consolidated portfolio held 2,076 securities with a carrying value of $18,764.0 million and unrealized losses of $541.3 million reflecting an average price of 97 as of December 31, 2018. Of this portfolio, 92% was investment grade (rated AAA through BBB-) as of December 31, 2018, with associated unrealized losses of $473.7 million. The unrealized losses on these securities can primarily be attributed to changes in market interest rates and changes in credit spreads since the securities were acquired.

For those securities that had been in a continuous unrealized loss position greater than or equal to twelve months, Principal Life's consolidated portfolio held 2,335 securities with a carrying value of $16,287.9 million and unrealized losses of $661.6 million. The average credit rating of this portfolio was AA- with an average price of 96 as of December 31, 2018. Of the $661.6 million in unrealized losses, the corporate sector accounts for $360.4 million in unrealized losses with an average price of 95 and an average credit rating of A-. The remaining unrealized losses also include $82.2 million within the commercial

mortgage-backed securities sector with an average price of 96 and an average credit rating of AA+. The unrealized losses on these securities can primarily be attributed to changes in market interest rates and changes in credit spreads since the securities were acquired.

Net Unrealized Gains and Losses on Available-for-Sale Securities and Derivative Instruments

The net unrealized gains and losses on investments in available-for-sale securities, the noncredit component of impairment losses on fixed maturities available-for-sale and the net unrealized gains and losses on derivative instruments in cash flow hedge relationships are reported as separate components of stockholders' equity. The cumulative amount of net unrealized gains and losses on available-for-sale securities and derivative instruments in cash flow hedge relationships net of adjustments related to DAC and related actuarial balances, policyholder liabilities, noncontrolling interest and applicable income taxes was as follows:


	June 30, 2019		December 31, 2018
	(in millions)
Net unrealized gains on fixed maturities, available-for-sale (1)	$	4,029.5	$	400.8
Noncredit component of impairment losses on fixed maturities, available-for-sale		(56.1)		(53.6)
Net unrealized gains on derivative instruments		108.0		118.5
Adjustments for assumed changes in amortization patterns		(208.1)		30.3
Adjustments for assumed changes in policyholder liabilities		(1,051.4)		(293.7)
Net unrealized gains on other investments and noncontrolling interest adjustments		97.6		68.8
Provision for deferred income taxes		(628.8)		(63.8)
Net unrealized gains on available-for-sale securities and derivative instruments	$	2,290.7	$	207.3

(1)	Excludes net unrealized gains (losses) on fixed maturities, available-for-sale included in fair value hedging relationships.

Mortgage Loans

Mortgage loans consist of commercial and residential mortgage loans. We evaluate risks inherent in our commercial mortgage loans in two classes: (1) brick and mortar property loans, including mezzanine loans, where we analyze the property's rent payments as support for the loan, and (2) credit tenant loans (“CTL”), where we rely on the credit analysis of the tenant for the repayment of the loan. We evaluate risks inherent in our residential mortgage loan portfolio in two classes: (1) first lien mortgages and (2) home equity mortgages. The carrying amount of our mortgage loan portfolio was as follows:


	June 30, 2019		December 31, 2018
	(in millions)
Commercial mortgage loans	$	14,830.6	$	13,996.3
Residential mortgage loans		1,334.3		1,368.0
Total amortized cost		16,164.9		15,364.3

Valuation allowance		(28.1)		(27.4)
Total carrying value	$	16,136.8	$	15,336.9

We periodically purchase mortgage loans as well as sell mortgage loans we have originated. Mortgage loans purchased and sold were as follows:

For the three months ended

For the six months ended

June 30,

2019

2018

2019

2018

(in millions)

Commercial mortgage loans:

Purchased

103.0

—

115.9

—

Sold

—

1.6

0.5

1.6

Residential mortgage loans:

Purchased

66.2

92.6

99.4

204.8

Sold

21.2

27.7

32.1

51.3

Our commercial mortgage loan portfolio consists primarily of non-recourse, fixed rate mortgages on stabilized properties. Our commercial mortgage loan portfolio is diversified by geographic region and specific collateral property type as follows:


	June 30, 2019				December 31, 2018
	Amortized		Percent		Amortized		Percent
	cost		of total		cost		of total
	($ in millions)
Geographic distribution
New England	$	652.6	4.4	%	$	640.6	4.6	%
Middle Atlantic		4,263.9	28.7			3,927.3	28.0
East North Central		604.9	4.1			592.8	4.2
West North Central		200.5	1.4			205.8	1.5
South Atlantic		2,338.0	15.8			2,206.5	15.8
East South Central		444.8	3.0			422.5	3.0
West South Central		1,463.1	9.9			1,213.8	8.7
Mountain		897.2	6.0			968.6	6.9
Pacific		3,686.2	24.9			3,567.6	25.5
International		279.4	1.8			250.8	1.8
Total	$	14,830.6	100.0	%	$	13,996.3	100.0	%

Property type distribution
Office	$	4,960.6	33.4	%	$	4,625.8	33.0	%
Retail		2,118.9	14.3			2,305.6	16.5
Industrial		2,350.5	15.8			2,312.9	16.5
Apartments		4,850.1	32.7			4,250.5	30.4
Hotel		97.9	0.7			99.8	0.7
Mixed use/other		452.6	3.1			401.7	2.9
Total	$	14,830.6	100.0	%	$	13,996.3	100.0	%

Our residential mortgage loan portfolio is composed of first lien mortgages with an amortized cost of $1,321.6 million and $1,352.9 million and home equity mortgages with an amortized cost of $12.7 million and $15.1 million as of June 30, 2019 and December 31, 2018, respectively. Our first lien loans are concentrated in Chile and the United States. Our residential home equity mortgages are concentrated in the United States and are generally second lien mortgages comprised of closed-end loans and lines of credit.

Mortgage Loan Credit Monitoring

Commercial Credit Risk Profile Based on Internal Rating

We actively monitor and manage our commercial mortgage loan portfolio. All commercial mortgage loans are analyzed regularly and substantially all are internally rated, based on a proprietary risk rating cash flow model, in order to monitor the financial quality of these assets. The model stresses expected cash flows at various levels and at different points

in time depending on the durability of the income stream, which includes our assessment of factors such as location (macro and micro markets), tenant quality and lease expirations. Our internal rating analysis presents expected losses in terms of an S&P Global (“S&P”) bond equivalent rating. As the credit risk for commercial mortgage loans increases, we adjust our internal ratings downward with loans in the category “B+ and below” having the highest risk for credit loss. Internal ratings on commercial mortgage loans are updated at least annually and potentially more often for certain loans with material changes in collateral value or occupancy and for loans on an internal “watch list”.

Commercial mortgage loans that require more frequent and detailed attention are identified and placed on an internal “watch list”. Among the criteria that would indicate a potential problem are significant negative changes in ratios of loan to value or contract rents to debt service, major tenant vacancies or bankruptcies, borrower sponsorship problems, late payments, delinquent taxes and loan relief/restructuring requests.

The amortized cost of our commercial mortgage loan portfolio by credit risk, as determined by our internal rating system expressed in terms of an S&P bond equivalent rating, was as follows:


	June 30, 2019
	Brick and mortar		CTL		Total
	(in millions)
A- and above	$	13,714.8	$	80.6	$	13,795.4
BBB+ thru BBB-		855.0		89.9		944.9
BB+ thru BB-		84.7		—		84.7
B+ and below		5.6		—		5.6
Total	$	14,660.1	$	170.5	$	14,830.6


	December 31, 2018
	Brick and mortar		CTL		Total
	(in millions)
A- and above	$	12,735.2	$	84.3	$	12,819.5
BBB+ thru BBB-		977.3		105.7		1,083.0
BB+ thru BB-		88.3		—		88.3
B+ and below		5.5		—		5.5
Total	$	13,806.3	$	190.0	$	13,996.3

Residential Credit Risk Profile Based on Performance Status

Our residential mortgage loan portfolio is monitored based on performance of the loans. Monitoring on a residential mortgage loan increases when the loan is delinquent or earlier if there is an indication of potential impairment. We define non-performing residential mortgage loans as loans 90 days or greater delinquent or on non-accrual status.

The amortized cost of our performing and non-performing residential mortgage loans was as follows:


	June 30, 2019
	First liens		Home equity		Total
	(in millions)
Performing	$	1,310.4	$	9.3	$	1,319.7
Non-performing		11.2		3.4		14.6
Total	$	1,321.6	$	12.7	$	1,334.3


	December 31, 2018
	First liens		Home equity		Total
	(in millions)
Performing	$	1,340.3	$	10.8	$	1,351.1
Non-performing		12.6		4.3		16.9
Total	$	1,352.9	$	15.1	$	1,368.0

Non-Accrual Mortgage Loans

Commercial and residential mortgage loans are placed on non-accrual status if we have concern regarding the collectability of future payments or if a loan has matured without being paid off or extended. Factors considered may include conversations with the borrower, loss of major tenant, bankruptcy of borrower or major tenant, decreased property cash flow for commercial mortgage loans or number of days past due and other circumstances for residential mortgage loans. Based on an assessment as to the collectability of the principal, a determination is made to apply any payments received either against the principal, against the valuation allowance or according to the contractual terms of the loan. When a loan is placed on non-accrual status, the accrued unpaid interest receivable is reversed against interest income. Accrual of interest resumes after factors resulting in doubts about collectability have improved. Residential first lien mortgages in the Chilean market are carried on accrual for a longer period of delinquency than domestic loans, as assessment of collectability is based on the nature of the loans and collection practices in that market.

The amortized cost of mortgage loans on non-accrual status was as follows:


	June 30, 2019		December 31, 2018
	(in millions)
Residential:
First liens	$	9.2	$	10.1
Home equity		3.4		4.3
Total	$	12.6	$	14.4

The aging of our mortgage loans, based on amortized cost, was as follows:

June 30, 2019

Recorded

investment

90 days or

30-59 days

60-89 days

more past

Total past

more and

past due

due

Current

Total loans

accruing

(in millions)

Commercial-brick and mortar

—

14,660.1

—

Commercial-CTL

—

170.5

—

Residential-first liens

42.2

7.3

10.0

59.5

1,262.1

1,321.6

2.0

Residential-home equity

0.7

—

0.7

12.0

12.7

—

Total

42.9

7.3

10.0

60.2

16,104.7

16,164.9

2.0


	December 31, 2018
													Recorded
													investment
					90 days or								90 days or
	30-59 days		60-89 days		more past		Total past						more and
	past due		past due		due		due		Current		Total loans		accruing
	(in millions)
Commercial-brick and mortar	$	—	$	—	$	—	$	—	$	13,806.3	$	13,806.3	$	—
Commercial-CTL		—		—		—		—		190.0		190.0		—
Residential-first liens		44.3		8.4		12.1		64.8		1,288.1		1,352.9		2.5
Residential-home equity		0.8		0.6		0.4		1.8		13.3		15.1		—
Total	$	45.1	$	9.0	$	12.5	$	66.6	$	15,297.7	$	15,364.3	$	2.5

Mortgage Loan Valuation Allowance

We establish a valuation allowance to provide for the risk of credit losses inherent in our portfolio. The valuation allowance includes loan specific reserves for loans that are deemed to be impaired as well as reserves for pools of loans with similar risk characteristics where a property risk or market specific risk has not been identified but for which we anticipate a loss may occur. Mortgage loans on real estate are considered impaired when, based on current information and events, it is probable we will be unable to collect all amounts due according to contractual terms of the loan agreement. When we determine a loan is impaired, a valuation allowance is established equal to the difference between the carrying amount of the mortgage loan and the estimated value reduced by the cost to sell. Estimated value is based on either the present value of the

expected future cash flows discounted at the loan's effective interest rate, the loan's observable market price or fair value of the collateral. Subsequent changes in the estimated value are reflected in the valuation allowance. Amounts on loans deemed to be uncollectible are charged off and removed from the valuation allowance. The change in the valuation allowance provision is included in net realized capital gains (losses) on our consolidated statements of operations.

The valuation allowance is maintained at a level believed adequate by management to absorb estimated probable credit losses. Management's periodic evaluation and assessment of the valuation allowance adequacy is based on 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, portfolio delinquency information, underwriting standards, peer group information, current economic conditions, loss experience and other relevant factors. The evaluation of our impaired loan component is subjective, as it requires the estimation of timing and amount of future cash flows expected to be received on impaired loans.

We review our commercial mortgage loan portfolio and analyze the need for a valuation allowance for any loan that is delinquent for 60 days or more, in process of foreclosure, restructured, on the internal “watch list” or that currently has a valuation allowance. In addition to establishing allowance levels for specifically identified impaired commercial mortgage loans, management determines an allowance for all other loans in the portfolio for which historical experience and current economic conditions indicate certain losses exist. These loans are segregated by risk rating level with an estimated loss ratio applied against each risk rating level. The loss ratio is generally based upon historical loss experience for each risk rating level as adjusted for certain current environmental factors management believes to be relevant.

For our residential mortgage loan portfolio, we separate the loans into several homogeneous pools, each of which consist of loans of a similar nature including but not limited to loans similar in collateral, term and structure and loan purpose or type. We evaluate loan pools based on aggregated risk ratings, estimated specific loss potential in the different classes of credits, and historical loss experience by pool type. We adjust these quantitative factors for qualitative factors of present conditions. Qualitative factors include items such as economic and business conditions, changes in the portfolio, value of underlying collateral and concentrations. Residential mortgage loan pools exclude loans that have been restructured or impaired, as those loans are evaluated individually.

A rollforward of our valuation allowance and ending balances of the allowance and loan balance by basis of impairment method was as follows:


	For the three months ended June 30, 2019
	Commercial		Residential		Total
	(in millions)
Beginning balance	$	24.7	$	2.9	$	27.6
Provision		0.7		(0.8)		(0.1)
Charge-offs		—		(0.3)		(0.3)
Recoveries		—		0.9		0.9
Ending balance	$	25.4	$	2.7	$	28.1


	For the six months ended June 30, 2019
	Commercial		Residential		Total
	(in millions)
Beginning balance	$	24.3	$	3.1	$	27.4
Provision		1.1		(1.6)		(0.5)
Charge-offs		—		(0.4)		(0.4)
Recoveries		—		1.6		1.6
Ending balance	$	25.4	$	2.7	$	28.1

Allowance ending balance by basis of impairment method:
Individually evaluated for impairment	$	—	$	1.5	$	1.5
Collectively evaluated for impairment		25.4		1.2		26.6
Allowance ending balance	$	25.4	$	2.7	$	28.1

Loan balance by basis of impairment method:
Individually evaluated for impairment	$	—	$	13.3	$	13.3
Collectively evaluated for impairment		14,830.6		1,321.0		16,151.6
Loan ending balance	$	14,830.6	$	1,334.3	$	16,164.9


	For the three months ended June 30, 2018
	Commercial		Residential		Total
	(in millions)
Beginning balance	$	26.6	$	6.4	$	33.0
Provision		(0.8)		(1.8)		(2.6)
Charge-offs		—		(1.1)		(1.1)
Recoveries		—		0.8		0.8
Ending balance	$	25.8	$	4.3	$	30.1


	For the six months ended June 30, 2018
	Commercial		Residential		Total
	(in millions)
Beginning balance	$	25.8	$	6.9	$	32.7
Provision		—		(2.8)		(2.8)
Charge-offs		—		(1.6)		(1.6)
Recoveries		—		1.8		1.8
Ending balance	$	25.8	$	4.3	$	30.1

Allowance ending balance by basis of impairment method:
Individually evaluated for impairment	$	—	$	2.0	$	2.0
Collectively evaluated for impairment		25.8		2.3		28.1
Allowance ending balance	$	25.8	$	4.3	$	30.1

Loan balance by basis of impairment method:
Individually evaluated for impairment	$	—	$	11.0	$	11.0
Collectively evaluated for impairment		13,071.9		1,315.1		14,387.0
Loan ending balance	$	13,071.9	$	1,326.1	$	14,398.0

Impaired Mortgage Loans

Impaired mortgage loans are loans with a related specific valuation allowance, loans whose carrying amount has been reduced to the expected collectible amount because the imp been considered other than temporary or a loan modification has been classified as a troubled debt restructuring (“TDR”). Based on an assessment as to the collectability of the principal, a determination is made to apply any payments received either against the principal, against the valuation allowance or according to the contractual terms of the loan. Our recorded investment in and unpaid principal balance of

impaired loans along with the related loan specific allowance for losses, if any, and the average recorded investment and interest income recognized during the time the loans were impaired were as follows:


	June 30, 2019
			Unpaid
	Recorded		principal		Related
	investment		balance		allowance
	(in millions)
With no related allowance recorded:
Residential-first liens	$	0.9	$	0.9	$	—
With an allowance recorded:
Residential-first liens		7.7		7.7		0.2
Residential-home equity		4.7		5.7		1.3
Total:
Residential	$	13.3	$	14.3	$	1.5


	December 31, 2018
			Unpaid
	Recorded		principal		Related
	investment		balance		allowance
	(in millions)
With no related allowance recorded:
Residential-first liens	$	1.6	$	1.6	$	—
With an allowance recorded:
Residential-first liens		2.2		2.2		—
Residential-home equity		5.4		6.5		1.4
Total:
Residential	$	9.2	$	10.3	$	1.4

For the three months ended

For the six months ended

June 30, 2019

Average

recorded

Interest income

recorded

Interest income

investment

recognized

investment

recognized

(in millions)

With no related allowance recorded:

Residential-first liens

0.9

—

1.3

—

With an allowance recorded:

Residential-first liens

4.9

—

5.0

—

Residential-home equity

4.9

0.1

5.1

0.1

Total:

Residential

10.7

0.1

11.4

0.1


	For the three months ended				For the six months ended
	June 30, 2018				June 30, 2018
	Average				Average
	recorded		Interest income		recorded		Interest income
	investment		recognized		investment		recognized
	(in millions)
With no related allowance recorded:
Residential-first liens	$	0.8	$	—	$	0.8	$	—
With an allowance recorded:
Residential-first liens		3.9		0.1		3.9		0.1
Residential-home equity		6.9		—		7.1		0.1
Total:
Residential	$	11.6	$	0.1	$	11.8	$	0.2

Mortgage Loan Modifications

Our commercial and residential mortgage loan portfolios can include loans that have been modified. We assess loan modifications on a case-by-case basis to evaluate whether a TDR has occurred. When we have commercial mortgage loan TDRs, they are modified to delay or reduce principal payments and to reduce or delay interest payments. The commercial mortgage loan modifications result in delayed cash receipts, a decrease in interest income and loan rates that are considered below market. When we have residential mortgage loan TDRs, they include modifications of interest-only payment periods, delays in principal balloon payments and interest rate reductions. Residential mortgage loan modifications result in delayed or decreased cash receipts and a decrease in interest income.

When we have commercial mortgage loan TDRs, they are reserved for in the mortgage loan valuation allowance at the estimated fair value of the underlying collateral reduced by the cost to sell.

When we have residential mortgage loan TDRs, they are specifically reserved for in the mortgage loan valuation allowance if losses result from the modification. Residential mortgage loans that have defaulted or have been discharged through bankruptcy are reduced to the expected collectible amount.

We did not have any significant loans that were modified and met the criteria of a TDR for the three and six months ended June 30, 2019 and 2018.

Securities Posted as Collateral

As of June 30, 2019 and December 31, 2018, we posted $3,681.9 million and $3,761.3 million, respectively, in commercial mortgage loans and residential first lien mortgages to satisfy collateral requirements associated with our obligation under funding agreements with Federal Home Loan Bank of Des Moines (“FHLB Des Moines”). In addition, as of June 30, 2019 and December 31, 2018, we posted $2,911.3 million and $2,402.5 million, respectively, in fixed maturities, available-for-sale and trading securities to satisfy collateral requirements primarily associated with a reinsurance arrangement, our derivative credit support annex (collateral) agreements, Futures Commission Merchant (“FCM”) agreements, a lending arrangement and our obligation under funding agreements with FHLB Des Moines. Since we did not relinquish ownership rights on these instruments, they are reported as mortgage loans, fixed maturities, available-for-sale and fixed maturities, trading, respectively, on our consolidated statements of financial position. Of the securities posted as collateral, as of June 30, 2019 and December 31, 2018, $149.1 million and $124.2 million, respectively, could be sold or repledged by the secured party.

Balance Sheet Offsetting

Financial assets subject to master netting agreements or similar agreements were as follows:


			Gross amounts not offset in the
			consolidated statements
			of financial position
	Gross amount
	of recognized		Financial		Collateral
	assets (1)		instruments (2)		received		Net amount
	(in millions)
June 30, 2019
Derivative assets	$	280.4	$	(80.9)	$	(188.3)	$	11.2
Reverse repurchase agreements		74.6		—		(74.6)		—
Total	$	355.0	$	(80.9)	$	(262.9)	$	11.2

December 31, 2018
Derivative assets	$	186.3	$	(70.5)	$	(108.1)	$	7.7
Reverse repurchase agreements		53.0		—		(53.0)		—
Total	$	239.3	$	(70.5)	$	(161.1)	$	7.7

(1)

The gross amount of recognized derivative and reverse repurchase agreement assets are reported with other investments and cash and cash equivalents, respectively, on the consolidated statements of financial position. The above excludes $11.1 million and $7.7 million of derivative assets as of June 30, 2019 and December 31, 2018, respectively, that are not subject to master netting agreements or similar agreements. The gross amounts of derivative and reverse repurchase

agreement assets are not netted against offsetting liabilities for presentation on the consolidated statements of financial position.

(2)	Represents amount of offsetting derivative liabilities that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative assets for presentation on the consolidated statements of financial position.

Financial liabilities subject to master netting agreements or similar agreements were as follows:

Gross amounts not offset in the

consolidated statements

of financial position

Gross amount

of recognized

Financial

Collateral

liabilities (1)

instruments (2)

pledged

Net amount

(in millions)

June 30, 2019

Derivative liabilities

166.4

(80.9)

(76.4)

9.1

December 31, 2018

Derivative liabilities

153.4

(70.5)

(52.3)

30.6

(1)

The gross amount of recognized derivative liabilities is reported with other liabilities on the consolidated statements of financial position. The above excludes $215.5 million and $138.3 million of derivative liabilities as of June 30, 2019 and December 31, 2018, respectively, which are primarily embedded derivatives that are not subject to master netting agreements or similar agreements. The gross amounts of derivative liabilities are not netted against offsetting assets for presentation on the consolidated statements of financial position.

(2)	Represents amount of offsetting derivative assets that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative liabilities for presentation on the consolidated statements of financial position.

The financial instruments that are subject to master netting agreements or similar agreements include right of setoff provisions. Derivative instruments include provisions to setoff positions covered under the agreements with the same counterparties and provisions to setoff positions outside of the agreements with the same counterparties in the event of default by one of the parties. Derivative instruments also include collateral or variation margin provisions, which are generally settled daily with each counterparty. See Note 4, Derivative Financial Instruments, for further details.

Repurchase and reverse repurchase agreements include provisions to setoff other repurchase and reverse repurchase balances with the same counterparty. Repurchase and reverse repurchase agreements also include collateral provisions with the counterparties. For reverse repurchase agreements we require the counterparties to pledge collateral with a value greater than the amount of cash transferred. We have the right but do not sell or repledge collateral received in reverse repurchase agreements. Repurchase agreements are structured as secured borrowings for all counterparties. We pledge fixed maturities available-for-sale, which the counterparties have the right to sell or repledge. Interest incurred on repurchase agreements is reported as part of operating expenses on the consolidated statements of operations. Net proceeds related to repurchase agreements are reported as a component of financing activities on the consolidated statements of cash flows. We did not have any outstanding repurchase agreements as of June 30, 2019 and December 31, 2018.