Our Bankers Life segment is primarily administered from downtown Chicago, Illinois. In 2012, Bankers Life relocated from one downtown location to another. The new location has approximately 135,000 square feet leased under an agreement which expires in 2023. Bankers Life has subleased its prior location of 222,000 square feet through the remaining term of the lease which expires in 2018. We also lease 321 sales offices in various states totaling approximately 950,000 square feet. These leases generally are short-term in length, with remaining lease terms expiring between 2016 and 2021.
We measure segment performance by excluding the net loss on the sale of CLIC and gain (loss) on reinsurance transactions, the earnings of CLIC prior to being sold on July 1, 2014, net realized investment gains (losses), fair value changes in embedded derivative liabilities (net of related amortization), fair value changes in the agent deferred compensation plan, loss on extinguishment or modification of debt, income taxes and other non-operating items consisting primarily of equity in earnings of certain non-strategic investments and earnings attributable to variable interest entities ("VIEs") ("pre-tax operating earnings") because we believe that this performance measure is a better indicator of the ongoing business and trends in our business. Our primary investment focus is on investment income to support our liabilities for insurance products as opposed to the generation of net realized investment gains (losses), and a long-term focus is necessary to maintain profitability over the life of the business.
The following summarizes the components of the reserves related to our long-term care business in our Bankers Life segment as well as the long-term care reserves ceded to BRe as of December 31, 2015 and 2014 (dollars in millions):
With respect to the long-term care block in our Bankers Life segment, the aggregate liability is not deficient, but our projections of estimated future profits (losses) indicate that profits will be recognized in earlier periods, followed by losses in later periods. In this situation, we are required to recognize future loss reserves. Such reserves are calculated based on our current estimate of the amount necessary to offset the losses in future periods and are established during the period the block is profitable. We estimate the future losses based on our current best estimates of morbidity, persistency, premium rates, maintenance expense and investment yields, which estimates are generally updated annually. During 2015, we increased the future loss reserves related to our long-term care blocks of business by $38.2 million based on these calculations.
Amortization related to operations includes amortization of deferred acquisition costs and the present value of future profits. Deferred acquisition costs and the present value of future profits are collectively referred to as "insurance acquisition costs". Insurance acquisition costs are generally amortized either: (i) in relation to the estimated gross profits for interest-sensitive life and annuity products; or (ii) in relation to actual and expected premium revenue for other products. In addition, for interest-sensitive life and annuity products, we are required to adjust the total amortization recorded to date through the statement of operations if actual experience or other evidence suggests that earlier estimates of future gross profits should be revised. Accordingly, amortization for interest-sensitive life and annuity products is dependent on the profits realized during the period and on our expectation of future profits. For other products, we amortize insurance acquisition costs in relation to actual and expected premium revenue, and amortization is only adjusted if expected premium revenue changes or if we determine the balance of these costs is not recoverable from future profits. Amortization was impacted in 2015 and 2014 by our comprehensive review of actuarial assumptions discussed above under insurance policy benefits.
Amortization related to net realized investment gains (losses) is the increase or decrease in the amortization of insurance acquisition costs which results from realized investment gains or losses. When we sell securities which back our interest-sensitive life and annuity products at a gain (loss) and reinvest the proceeds at a different yield, we increase (reduce) the amortization of insurance acquisition costs in order to reflect the change in estimated gross profits due to the gains (losses) realized and the resulting effect on estimated future yields. Sales of fixed maturity investments resulted in an increase (decrease) in the amortization of insurance acquisition costs of $(.5) million, $.5 million and $1.2 million in 2015, 2014 and 2013, respectively.
These non-GAAP financial measures of "interest-adjusted benefit ratios" differ from "benefit ratios" due to the deduction of imputed interest income on the accumulated assets backing the insurance liabilities from the product’s insurance policy benefits used to determine the ratio. Interest income is an important factor in measuring the performance of health products that are expected to be inforce for a longer duration of time, are not subject to unilateral changes in provisions (such as non-cancelable or guaranteed renewable contracts) and require the performance of various functions and services (including insurance protection) for an extended period of time. The net cash flows from supplemental health products generally cause an accumulation of amounts in the early years of a policy (accounted for as reserve increases) that will be paid out as benefits in later policy years (accounted for as reserve decreases). Accordingly, as the policies age, the benefit ratio will typically increase, but the increase in benefits will be partially offset by the imputed interest income earned on the accumulated assets. The interest-adjusted benefit ratio reflects the effects of such interest income offset (which is equal to the tabular interest on the related insurance liabilities). Since interest income is an important factor in measuring the performance of these products, management believes a benefit ratio that includes the effect of interest income is useful in analyzing product performance. We utilize the interest-adjusted benefit ratio in measuring segment performance because we believe that this performance measure is a better indicator of the ongoing businesses and trends in the business. However, the "interest-adjusted benefit ratio" does not replace the "benefit ratio" as a measure of current period benefits to current period insurance policy income. Accordingly, management reviews both "benefit ratios" and "interest-adjusted benefit ratios" when analyzing the financial results attributable to these products. The imputed investment income earned on the accumulated assets backing the supplemental health reserves was $132.6 million, $130.2 million and $126.4 million in 2015, 2014 and 2013, respectively.
Net investment income related to fixed index products represents the change in the estimated fair value of options which are purchased in an effort to offset or hedge certain potential benefits accruing to the policyholders of our fixed index products. Our fixed index products are designed so that investment income spread is expected to be more than adequate to cover the cost of the options and other costs related to these policies. Net investment income (loss) related to fixed index products was $(2.2) million, $6.3 million and $17.9 million in 2015, 2014 and 2013, respectively. Such amounts were substantially offset by the corresponding charge to amounts added to policyholder account balances - market value changes credited to policyholders. Such income and related charges fluctuate based on the value of options embedded in the segment's fixed index annuity policyholder account balances subject to this benefit and to the performance of the index to which the returns on such products are linked.
Net investment income on general account invested assets increased in 2015 and 2014 primarily due to the increase in invested assets as a result of growth in this segment.
Other operating costs and expenses in our Colonial Penn segment fluctuate primarily due to changes in the marketing expenses incurred to generate new business. Although marketing expenses increased by approximately $6 million in 2015, our mix of marketing activities has resulted in a similar increase in the deferral of such acquisition costs. We continue to face increased competition from other insurance companies who also distribute products through direct marketing. In addition, the demand and cost of television advertising appropriate for Colonial Penn's campaigns has fluctuated widely in certain periods. In some periods, increased advertising costs have resulted in decisions to lower our planned spending. These factors may reoccur in the future.
The EBIT from in-force business in the Bankers Life segment (as summarized on page 82) decreased in 2015, consistent with the explanations in the segment's results of operations section, including the impacts of: (i) favorable claim developments in 2014 which did not reoccur in 2015; (ii) higher expenses reflecting investments being made to support future sales growth and expense reductions; partially offset by: (iii) the favorable impacts from our comprehensive annual actuarial review compared to 2014; and (iv) higher prepayment income. The EBIT from in-force business in the Bankers Life segment grew in 2014 primarily due to the growth in the size of the block. The EBIT from new business in the Bankers Life segment reflects new sales.
At December 31, 2015, 45 percent of our Level 3 fixed maturities, available for sale, were investment grade and 82 percent of our Level 3 fixed maturities, available for sale, consisted of corporate securities.
Our fixed maturity portfolio at December 31, 2015, included primarily debt securities of the United States government, various corporations, and structured securities. Asset-backed securities, collateralized debt obligations, commercial mortgage-backed securities, mortgage pass-through securities and collateralized mortgage obligations are collectively referred to as "structured securities".
At December 31, 2015, our fixed maturity portfolio had $1,324.4 million of unrealized gains and $388.5 million of unrealized losses, for a net unrealized gain of $935.9 million. Estimated fair values of fixed maturity investments were determined based on estimates from: (i) nationally recognized pricing services (90 percent of the portfolio); (ii) broker-dealer market makers (1 percent of the portfolio); and (iii) internally developed methods (9 percent of the portfolio).
At December 31, 2015, we held investments with an amortized cost of $1,679.3 million and an estimated fair value of $1,633.6 million related to variable interest entities that we are required to consolidate. The investment portfolio held by the variable interest entities is primarily comprised of commercial bank loans, the borrowers for which are almost entirely rated below-investment grade. Refer to the note to the consolidated financial statements entitled "Investments in Variable Interest Entities" for additional information on these investments.
"Derivatives". These repurchase agreements are accounted for as collateralized financing arrangements and not as a sale and subsequent repurchase of securities. There were no such borrowings outstanding at December 31, 2015. We had $20.4 million of such borrowings outstanding at December 31, 2014.
The following table sets forth the par value, amortized cost and estimated fair value of structured securities, summarized by interest rates on the underlying collateral, at December 31, 2015 (dollars in millions):
derivatives and changes in fair value of embedded derivative instruments included in liabilities for insurance products that exist as of the reporting date.
this uncertainty, we have not recognized a tax benefit of $166.0 million. However, if this unrecognized tax benefit would have been recognized, we would also have established a valuation allowance of $34.0 million at December 31, 2015.
In 2014, we recognized a loss on extinguishment or modification of debt totaling $.6 million consisting of: (i) $.4 million of expenses related to the amendment of the Previous Senior Secured Credit Agreement; and (ii) $.2 million related to the repurchase of the remaining principal amount of the 7.0% Debentures.
The scheduled repayment of our direct corporate obligations was as follows at December 31, 2015 (dollars in millions):
In connection with the closing of the transaction, CNO Services, LLC ("CNO Services"), an indirect wholly owned subsidiary of CNO, entered into a transition services agreement and a special support services agreement with Wilton Re, pursuant to which CNO Services makes available to Wilton Re and its affiliates, for a limited period of time, certain services required for the operation of CLIC's business following the closing. Under such agreements, we will receive $30 million in the year ending June 30, 2015 and $20 million in the year ending June 30, 2016. In addition, certain services will continue to be provided in the three years ending June 30, 2019 for an annual fee of $.2 million. The costs of the services provided to Wilton Re are expected to approximate the fees received under the agreements.
The investment portfolios held by the VIEs are primarily comprised of commercial bank loans to corporate obligors which are almost entirely rated below-investment grade. At December 31, 2015, such loans had an amortized cost of $1,679.3 million; gross unrealized gains of $.5 million; gross unrealized losses of $46.2 million; and an estimated fair value of $1,633.6 million.
The following table sets forth the amortized cost and estimated fair value of the investments held by the VIEs at December 31, 2015, by contractual maturity. Actual maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalties.
During 2015, $46.1 million of investments held by the VIEs were sold which resulted in gross investment losses (before income taxes) of $1.8 million. During 2014, $38.7 million of investments held by the VIEs were sold which resulted in gross investment losses (before income taxes) of $2.4 million. During 2013, $11.1 million of investments held by the VIEs were sold which resulted in gross investment losses (before income taxes) of $.9 million.