Topic 740, No. 5,  Accounting for Global Intangible Low-Taxed Income , states that an entity can make an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. At December 31, 2018, the Company elected to account for GILTI in the year the tax is incurred. Deferred income taxes consisted of the following at December 31, 2019 and 2018: At December 31, 2019, the Company had deferred tax assets related to loss carryforwards of $26,034,000, before netting of unrecognized tax benefits of $511,000. An estimated $16,342,000 of the deferred tax assets will not expire, and $9,692,000 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, 2019, 2018, and 2017. Changes to the valuation allowance for the year ended December 31, 2019 were primarily due to anticipated expiration of certain state NOLs after consideration of the four sources of taxable income and losses in certain of the Company’s international operations. 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. 81 2019 2018 2017 (In thousands) Balance, beginning of year $ 25,864 $ 18,829 $ 14,498 Other changes 2,264 7,035 4,331 Balance, end of year $ 28,128 $ 25,864 $ 18,829 2019 2018 (In thousands) Accounts receivable allowance $ 1,163 $ 1,534 Accrued compensation 9,553 10,184 Accrued pension liabilities 9,116 13,496 Self-insured risks 4,301 4,933 Deferred revenues 4,249 5,868 Accrued rent — 3,115 Interest 5,399 5,665 Tax credit carryforwards 11,634 14,404 Loss carryforwards 25,523 25,745 Lease liability 29,785 — Other 3,436 1,152 Gross deferred income tax assets 104,159 86,096 Unbilled revenues 6,522 7,725 Depreciation and amortization 28,025 32,510 Lease right-of-use asset 25,865 — Gross deferred income tax liabilities 60,412 40,235 Net deferred income tax assets before valuation allowance 43,747 45,861 Valuation allowance (28,128) (25,864) Net deferred income tax assets $ 15,619 $ 19,997 Amounts recognized in the Consolidated Balance Sheets consist of: Long-term deferred income tax assets included in "Deferred income tax assets" 17,971 22,146 Long-term deferred income tax liabilities included in "Other noncurrent liabilities" (2,352) (2,149) Net deferred income tax assets $ 15,619 $ 19,997 Table of Contents