issued and outstanding as of December 31, 2016, and December 31, 2015, respectively
Mortgage- and asset-backed securities (“ABS”) - We also utilize additional inputs, which include new issues data, monthly payment information and monthly collateral performance, including prepayments, severity, delinquencies, step-down features and over collateralization features for each of our mortgage-backed securities (“MBS”), which include collateralized mortgage obligations and
In periods subsequent to the recognition of an OTTI, the AFS security is accounted for as if it had been purchased on the measurement date of the OTTI. Therefore, for the fixed maturity AFS security, the original discount or reduced premium is reflected in net investment income over the contractual term of the investment in a manner that produces a constant effective yield.
Basic earnings per share (“EPS”) is computed by dividing earnings available to common shareholders by the average common shares outstanding. Diluted EPS is computed assuming the conversion or exercise of dilutive convertible preferred securities, nonvested stock, stock options, performance share units and warrants outstanding during the year. Effective October 1, 2016, we early adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting. We have updated certain previously reported interim results and metrics as of January 1, 2016, in accordance with the new guidance. The adoption of this ASU did not have a material effect on our diluted EPS calculation.
The following table provides a description of our adoption of new ASUs issued by the FASB and the impact of the adoption on our financial statements:
As of December 31, 2016, the unrealized losses associated with our MBS and ABS were attributable primarily to collateral losses and credit spreads. We assessed for credit impairment using a cash flow model that incorporates key assumptions including default rates, severities and prepayment rates. We estimated losses for a security by forecasting the underlying loans in each transaction. The forecasted loan performance was used to project cash flows to the various tranches in the structure, as applicable. Our forecasted cash flows also considered, as applicable, independent industry analyst reports and forecasts, sector credit ratings and other independent market data. Based upon our assessment of the expected credit losses of the security given the performance of the underlying collateral compared to our subordination or other credit enhancement, we expected to recover the entire amortized cost of each temporarily-impaired security.
We have derivative instruments with off-balance-sheet risks whose notional or contract amounts exceed the related credit exposure. Outstanding derivative instruments with off-balance-sheet risks (in millions) were as follows:
For the years ended December 31, 2016 and 2015, there were no material reclassifications to earnings due to hedged firm commitments no longer deemed probable or due to hedged forecasted transactions that had not occurred by the end of the originally specified time period.
Certain subsidiaries of ours lease their home office properties. In 2006, we exercised the right and option to extend the Fort Wayne lease for two extended terms such that the lease shall expire in 2019. We retain our right and option to exercise the remaining four extended terms of five years each in accordance with the lease agreement. These agreements also provide us with the right of first refusal to purchase the properties at a price defined in the agreements and the option to purchase the leased properties at fair market value on the