At December 31, 2013 and 2012, non-current deferred tax liabilities and non-current deferred tax assets, respectively, related to our investments, reflect deferred taxes on unrealized gains and losses on available-for-sale investments. The net  change in non-current deferred taxes associated with these investments, a deferred tax expense of $0.4 million in 2013 and a  deferred tax benefit of $33 thousand in 2012, is recorded as an adjustment to other comprehensive income, presented in the  Consolidated Statements of Comprehensive Income. We have deferred tax assets for foreign and domestic loss carry-forwards, unamortized research and development costs  and state credit carry-forwards of $19.0 million which will expire between 2014 and 2030. The foreign loss carry-forwards  were generated through the acquisition of a foreign entity in 2009 and through current losses at a foreign subsidiary. The unamortized research and development costs are related to our acquisition of Bluesocket in 2011. The state credit carry-for- wards result from tax credits in excess of our annual tax liability to an individual state where we do not generate sufficient state income to offset the credit. We believe it is more likely than not that we will not realize the full benefits of the deferred tax asset arising from these losses and credits in various states and foreign countries, and accordingly, we have provided a valuation allowance against these deferred tax assets. We do not provide for U.S. income tax on undistributed earnings of our foreign operations, whose earnings are intended to be permanently reinvested. These earnings are not required to service debt or fund our U.S. operations. During 2013, 2012 and 2011, we recorded an income tax benefit of $0.2 million, $1.9 million and $10.5 million, respectively, as an adjustment to equity. This deduction is calculated on the difference between the exercise price of stock option exercises and the market price of the underlying common stock upon exercise. The change in the unrecognized income tax benefits for 2013, 2012 and 2011 is reconciled below: As of December 31, 2013, 2012, and 2011, our total liability for unrecognized tax benefits was $3.2 million, $2.9 million,  and $3.0 million, respectively, of which $2.5 million, $2.2 million, and $2.4 million, respectively, would reduce our effective tax  rate if we were successful in upholding all of the uncertain positions and recognized the amounts recorded. We classify interest  and penalties recognized on the liability for unrecognized tax benefits as income tax expense. As of December 31, 2013, 2012  and 2011, the balances of accrued interest and penalties were $1.0 million, $0.8 million and $1.2 million, respectively. We do not anticipate a single tax position generating a significant increase or decrease in our liability for unrecognized tax  benefits within 12 months of this reporting date. We file income tax returns in the U.S. federal and various state jurisdictions  and several foreign jurisdictions. We have been audited by the Internal Revenue Service and the state of Alabama through the  2009 tax year. Generally, we are not subject to changes in income taxes by any taxing jurisdiction for the years prior to 2010. As a result of our acquisition of the NSN BBA business, we assumed a defined benefit pension plan covering employees  in certain foreign countries. We established a Contribution Trust Arrangement (CTA) to hold the pension assets, and NSN  transferred assets to us equal to the defined benefit obligation as of the May 4, 2012 acquisition date. 11  Employee Benefit Plans Pension Benefit Plan (In thousands) 2013 2012 2011 Balance at beginning of period $2,926 $2,970 $2,593 Increases for tax position related to: Prior years 89 965 — Current year 549 302 840 Decreases for tax positions related to: Prior years — (49) (92) Settlements with taxing authorities (141) (507) (354) Expiration of applicable statute of limitations (183) (755) (17) Balance at end of period $3,240 $2,926 $2,970 Financial Results 59