The fiscal year 2020 and 2019 amounts above exclude $142.1 million and $68.4 million, respectively, of unrecognized tax benefits that have been recorded as a reduction of non-current deferred tax assets, which is presented within non-current deferred tax liabilities due to jurisdictional netting on the consolidated balance sheets. A reconciliation of the beginning and ending amounts of  unrecognized tax benefits, excluding interest and penalties, is as follows: Our remaining unrecognized tax benefits as of December 31, 2020, relate to tax years that are currently open to examination. Annual tax provisions include amounts considered sufficient to pay assessments that may result from examination of prior year tax returns; however, the amount ultimately paid upon resolution of issues may differ materially from the amount accrued. Due to anticipated settlements and expected expiration of statutes of limitation, it is reasonably possible that the amount of unrecognized tax benefits may decrease by an amount up to $150 million within the next 12 months. (1) Amounts exclude the potential effects of valuation allowances, which may fully or partially offset the impact to the effective tax rate. 100 As of December 31, 2020 December 31, 2019 (In millions) Domestic net non-current deferred tax liabilities $ 1,542.8  $ 1,488.5  Foreign net non-current deferred tax assets 105.7  34.8  Foreign net non-current deferred tax liabilities 696.8  701.7  Net non-current deferred tax liabilities $ 2,133.9  $ 2,155.4  For the years ended December 31, 2020 December 31, 2019 December 31, 2018 (In millions) Balance at beginning of year $ 72.4  $ 51.6  $ 41.9  Additions for tax positions related to the current year 22.8  18.1  22.3  Additions for tax positions of prior years 132.1  —  0.7  Reductions for tax positions of prior years (1.6) —  (8.4) Settlements (0.4) —  —  Release due to statute expirations —  (0.8) (1.6) Foreign currency adjustment 10.4  3.5  (3.3) Balance at end of year $ 235.7  $ 72.4  $ 51.6  For the years ended December 31, 2020 December 31, 2019 December 31, 2018 (In millions) Reconciliation of unrecognized tax benefits balance Estimated interest and penalties $ 11.4  $ 2.9  $ 2.3  Unrecognized tax positions 235.7  72.4  51.6  Total unrecognized tax benefits $ 247.1  $ 75.3  $ 53.9  Presented net against non-current deferred tax assets $ 142.1  $ 68.4  $ 47.8  Current (included in accounts payable and other current liabilities) 98.0  —  —  Non-current (included within other liabilities) 7.0  6.9  6.1  Total unrecognized tax benefits $ 247.1  $ 75.3  $ 53.9  Amount of unrecognized tax benefits that would impact the effective tax rate, if recognized $ 87.7  $ 72.4  $ 51.6  (1)