The pending Department of Labor fiduciary rule that expands the regulation of sales of insurance products used in retirement plans. See Part 1, Item 1A for further discussion of this proposal.
Amounts are net of adjustments, as applicable, to amortization of unearned revenue reserves, deferred acquisition costs and value of insurance in force acquired, as well as changes in interest sensitive product reserves and income taxes attributable to these items.
Results for 2017 were unfavorably impacted by the correction of an immaterial error that decreased pre-tax operating earnings by $3.2 million. The error arose and accumulated over several years, with no prior year significantly impacted. As a result of the correction, interest sensitive product charges decreased by $3.2 million and interest credited, included in interest sensitive product benefits, increased $0.4 million.
Our direct exposure to the Alt-A home equity and subprime first-lien sectors is limited to investments in structured securities collateralized by senior tranches of residential mortgage loans. We also have a partnership interest in one fund at December 31, 2017 and two funds at December 31, 2016, that own securities backed by Alt-A home equity, subprime first-lien and adjustable rate mortgage collateral. The funds are reported as securities and indebtedness of related parties in our consolidated balance sheets with a fair value of $3.0 million at December 31, 2017 and $8.0 million at December 31, 2016. We do not own any direct investments in subprime lenders.
Farm Bureau Life's cash inflows primarily consist of premiums, deposits to policyholder account balances, income from investments, sales, maturities and calls of investments; and repayments of investment principal. Farm Bureau Life's cash outflows are primarily related to withdrawals of policyholder account balances, investment purchases, payment of policy acquisition costs, policyholder benefits, income taxes, current operating expenses and dividends. Life insurance companies generally produce a positive cash flow that may be measured by the degree to which cash inflows are adequate to meet benefit obligations to policyholders and normal operating expenses as they are incurred. The remaining cash flow is generally used to increase the asset base to provide funds to meet the need for future policy benefit payments and for writing new business. Continuing operations and financing activities from Farm Bureau Life relating to interest sensitive products provided funds totaling $325.2 million in 2017, $490.9 million in 2016 and $385.3 million in 2015.
We have audited the accompanying consolidated balance sheets of FBL Financial Group, Inc. (the Company) as of December 31, 2017 and 2016, and the related consolidated statements of operations, comprehensive income (loss), changes in stockholders' equity and cash flows for each of the three years in the period ended December 31, 2017, and the related notes and financial statement schedules listed in the Index at Item 15(a) (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2017 and 2016, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2017, in conformity with U.S. generally accepted accounting principles.
Other assets include property and equipment, primarily comprised of capitalized software costs and furniture and equipment, which are reported at cost less allowances for depreciation and amortization. We expense costs incurred in the preliminary stages of developing internal-use software as well as costs incurred post-implementation for maintenance. Capitalization of internal-use software costs occurs after management has authorized the project and it is probable that the software will be used as intended. Amortization of software costs begins after the software has been placed in production. Depreciation and amortization expense is computed primarily using the straight-line method over the estimated useful lives of the assets, which range from three to twenty years. Property and equipment had a carrying value of $35.8 million at December 31, 2017 and $33.5 million at December 31, 2016, and accumulated depreciation and amortization of $78.7 million at December 31, 2017 and $70.1 million at December 31, 2016. Depreciation and amortization expense for property and equipment was $8.7 million in 2017 and 2016, and $8.2 million in 2015.
annuity or universal life-type contracts that provide benefit guarantees, or for contracts that are expected to produce profits followed by losses. The liabilities are accrued in relation to estimated contract assessments. Policy benefits and claims that are charged to expense include benefit claims incurred in the period in excess of related policy account balances. Interest crediting rates for our interest sensitive products ranged from 1.00% to 5.50% in 2017, 2016 and 2015.
At December 31, 2017, we had committed to provide additional funds for limited partnerships and limited liability companies in which we invest. The amounts of these unfunded commitments totaled $51.0 million, including $1.7 million for commitments to LIHTC, which are summarized by year in the following table.
In the case for which external pricing services are used for certain Level 1 and Level 2 equity securities, our review process is consistent with the process used to determine the fair value of fixed maturities discussed above.
Unrealized net investment gains (losses) relate to available-for-sale securities and include the impact of taxes, deferred acquisition costs, value of insurance in force acquired, unearned revenue reserves and policyholder liabilities. See Note 2 for further information.
Contributions are made each year, resulting in the Multiemployer Plan being partially funded for payment of projected future benefit obligations. Effective in 2013, the Multiemployer Plan was closed to new participants and those participants who had not attained age 40 and 10 years of service as of December 31, 2012 no longer accrue additional years of service in the Multiemployer Plan.
Alternative investments: the carrying value of the limited partnership interests reflects the Plan’s proportionate share of the net asset value of those partnerships, which is derived from the fair value of the underlying holdings.
We participate with affiliated and unaffiliated employers in a 401(k) defined contribution plan, which covers substantially all employees. We match employee contributions up to 2% or 4% of the eligible compensation contributed by the employee and at an amount equal to 50% of an employee's contributions on the next 2% of the eligible compensation contributed by the employee. As shown in the table below, certain employees will also receive an annual discretionary employer contribution based on age plus years of service ranging from 2.75% to 5.75% as a percent of pay. Costs are allocated among the affiliates on a basis of time incurred by the respective employees for each company. Our expense related to this plan totaled $2.6 million in 2017, $2.4 million in 2016 and $2.2 million in 2015.
In addition to benefits offered under the aforementioned benefit plans, we participate with affiliated and unaffiliated employers in a plan that provides group term life insurance benefits to retirees. We froze our portion of the plan on December 31, 2016 such that no new participants will enter the plan. During 2016, we recognized $0.2 million in curtailment gain related to freezing the group term life benefits to retirees. We also have two single-employer plans, frozen to new participants, that provide health and medical benefits to a small group of retirees. Postretirement benefit (income)/expense for this plan is allocated in a manner consistent with pension expense discussed above and totaled ($0.1) million in 2017 and 2016 and $0.1
We also have an Executive Excess 401(k) Plan under which officers of the Company who met salary guidelines and 401(k) contribution guidelines were allowed to purchase unregistered deferred cash-based stock units. There were no cash-based stock units outstanding under this plan at December 31, 2017 and 89 at December 31, 2016. Prior to 2012, deferred stock units were used instead of deferred cash-based stock units. Under this plan, we have deferred stock units outstanding totaling 3,175 at December 31, 2017 and 3,168 at December 31, 2016. This plan was frozen to future deferrals on December 31, 2013.
We are licensed by the IFBF to use the "Farm Bureau" and "FB" designations in Iowa. In connection with this license, we incurred royalty expense totaling $0.6 million in 2017, 2016 and 2015. We have similar arrangements with other state Farm Bureau organizations in our market territory. Total royalty expense to Farm Bureau organizations other than the IFBF totaled $1.8 million in 2017 and in 2016 and $1.7 million in 2015. The royalty agreement with the IFBF provides IFBF an option to terminate the agreement if our quarterly common stock dividend is below $0.10 per share.