Table of Contents At December 31, 2018, the Company had deferred tax assets related to loss carryforwards of $26,164,000, before netting of unrecognized tax benefits of $419,000. An estimated $16,239,000 of the deferred tax assets will not expire, and $9,925,000 will expire over the next 20 years if not utilized by the Company. Changes in the Company's deferred tax valuation allowance are recorded as adjustments to the provision for income taxes. An analysis of the Company's deferred tax asset valuation allowances is as follows for the years ended December 31, 2018, 2017, and 2016. Changes to the valuation allowance for the year ended December 31, 2018 were primarily due to anticipated expiration of foreign tax credits after consideration of the Tax Act and the four sources of taxable income and losses in certain of the Company’s international and domestic operations. For the year ended December 31, 2017 the change was primarily due to losses in certain of the Company’s international operations and domestic operations impacting state NOLs. A reconciliation of the beginning and ending balance of unrecognized income tax benefits follows:  The Company accrues interest and, if applicable, penalties related to unrecognized tax benefits in income taxes. Total accrued interest expense at December 31, 2018, 2017, and 2016, was $256,000, $275,000, and $155,000, respectively. Included in the total unrecognized tax benefits at December 31, 2018, 2017, and 2016 were $5,493,000, $9,389,000, and $3,332,000, respectively, of tax benefits that, if recognized, would affect the effective income tax rate. The Company conducts business in a number of countries and, as a result, files U.S. federal and various state and foreign jurisdiction income tax returns. In the normal course of business, the Company is subject to examination by various taxing jurisdictions throughout the world, including Canada, the U.K., and the U.S. With few exceptions, the Company is no longer subject to income tax examinations for years before 2008. Although the outcome of tax audits is always uncertain, the Company believes that adequate amounts of tax, including interest and penalties, have been provided for any adjustments that are expected to result from those years. 2018 2017 2016 (In thousands) Balance, beginning of year $ 18,829 $ 14,498 $ 17,204 Other changes 7,035 4,331 (2,706) Balance, end of year $ 25,864 $ 18,829 $ 14,498 (In thousands) Balance at December 31, 2015 $ 6,187 Additions for tax provisions related to the current year 159 Reductions for tax positions related to the current year (989 ) Additions for tax positions related to prior years 278 Lapses of applicable statutes of limitation (166 ) Balance at December 31, 2016 $ 5,469 Additions for tax provisions related to the current year 6,318 Reductions for tax positions related to prior years (41) Additions for tax positions related to prior years 823 Lapses of applicable statutes of limitation (1,232) Currency translation adjustment (40 ) Balance at December 31, 2017 $ 11,297 Additions for tax provisions related to the current year 54 Reductions for tax positions related to prior years (3,941) Currency translation adjustment (9 ) Balance at December 31, 2018 $ 7,401 84