Net catastrophe losses for the year ended December 31, 2016 related primarily to U.S. weather-related events and the Fort McMurray wildfires.
We also purchased corporate Workers' Compensation catastrophe excess-of-loss treaty reinsurance for the period January 1, 2019 to January 1, 2020 providing $275 million of coverage for the accumulation of covered losses related to natural catastrophes above our retention of $25 million. The treaty also provides $475 million of coverage for the accumulation of covered losses related to terrorism events above our retention of $25 million. Of this $475 million in Terrorism coverage, $200 million is provided for nuclear, biological chemical and radiation events. One full reinstatement is available for the first $275 million above the retention, regardless of the covered peril. We also purchased a targeted facultative facility to address exposure accumulations in specific peak Terrorism zones.
The following table includes the consolidated results of our operations including our financial measure, Core income (loss). For more detailed components of our business operations and a discussion of the core income (loss) financial measure, see the segment sections within this MD&A. For further discussion of Net investment income and Net realized investment results, see the Investments section of this MD&A.
Favorable net prior year loss reserve development of $9 million and $58 million was recorded in 2017 and 2016. Further information on net prior year loss reserve development is in Note E to the Consolidated Financial Statements included under Item 8.
The Prior to Adoption amounts presented in this table include the cumulative effect adjustment at adoption presented in the prior table.
The Company classifies its fixed maturity securities as either available-for-sale or trading, and as such, they are carried at fair value. Changes in fair value of trading securities are reported within Net investment income on the Consolidated Statements of Operations. Changes in fair value related to available-for-sale securities are reported as a component of Other comprehensive income. Losses may be recognized within Net realized investment gains (losses) on the Consolidated Statements of Operations when a decline in value is determined by the Company to be other-than-temporary.
Goodwill is tested for impairment annually or when certain triggering events require such tests. As a result of reviews completed for the year ended December 31, 2018, the Company determined that the estimated fair value of the reporting units were in excess of their carrying value including Goodwill. Changes in future periods in assumptions about the level of economic capital, business growth, earnings projections or the weighted average cost of capital could result in a goodwill impairment.
Securities with carrying values of approximately $2.5 billion and $2.6 billion were deposited by the Company’s insurance subsidiaries under requirements of regulatory authorities and others as of December 31, 2018 and 2017.
The Company's reserving methodologies for mass tort and A&EP are similar as both are based on detailed reviews of large accounts with estimates of ultimate payments based on the facts in each case and the Company's view of applicable law and coverage litigation.
(2) The amounts included in the loss reserve development tables above are presented at the year-end 2018 foreign currency exchange rates for all periods presented to remove the effects of foreign currency exchange rate fluctuations between calendar years. The amounts included within the table on page 102 presenting the detail of the development recorded within the International segment include the impact of fluctuations in foreign currency exchange rates.
(3) The amounts included in the loss reserve development tables above are presented at the year-end 2018 foreign currency exchange rates for all periods presented to remove the effects of foreign currency exchange rate fluctuations between calendar years. The amounts included within the table on page 102 presenting the detail of the development recorded within the International segment include the impact of fluctuations in foreign currency exchange rates.
In the course of selling business entities and assets to third parties, the Company agreed to guarantee the performance of certain obligations of previously owned subsidiaries and to indemnify purchasers for losses arising out of breaches of representation and warranties with respect to the business entities or assets sold, including, in certain cases, losses arising from undisclosed liabilities or certain named litigation. Such guarantee and indemnification agreements in effect for sales of business entities, assets and third-party loans may include provisions that survive indefinitely. As of December 31, 2018, the aggregate amount related to quantifiable guarantees was $375 million and the aggregate amount related to quantifiable indemnification agreements was $252 million. In certain cases, should the Company be required to make payments under any such guarantee, it would have the right to seek reimbursement from an affiliate of a previously owned subsidiary.
The components of net periodic postretirement cost (benefit) are presented in the following table.
The table below presents the estimated future minimum benefit payments to participants as of December 31, 2018.