Business Overview and Significant Accounting Policies	9 Months Ended
Business Overview and Significant Accounting Policies	Sep. 27, 2020
Accounting Policies [Abstract]
Business Overview and Significant Accounting Policies	Business Overview and Significant Accounting Policies Unless we state otherwise or the context otherwise requires, references to "Masonite," "we," "our," "us" and the "Company" in these notes to the condensed consolidated financial statements refer to Masonite International Corporation and its subsidiaries. Description of Business Masonite International Corporation is one of the largest manufacturers of doors in the world, with significant market share in both interior and exterior door products. Masonite operates 62 manufacturing and distribution facilities in eight countries and sells doors to customers throughout the world with our largest markets being the United States, Canada and the United Kingdom. Basis of Presentation We prepare these unaudited condensed consolidated financial statements in accordance with accounting principles generally accepted in the United States of America ("GAAP") and applicable rules and regulations of the U.S. Securities and Exchange Commission ("SEC") regarding interim financial reporting. Accordingly, they do not include all of the information and notes required by GAAP for annual financial statements. In the opinion of management, all adjustments consisting of normal and recurring entries considered necessary for a fair presentation of the results for the interim periods presented have been included. All significant intercompany balances and transactions have been eliminated. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect reported amounts in the financial statements and accompanying notes. These estimates are based on information available as of the date of the unaudited condensed consolidated financial statements; therefore, actual results could differ from those estimates. Interim results are not necessarily indicative of the results for a full year. These unaudited condensed consolidated financial statements should be read in conjunction with the Company's Annual Report on Form 10-K for the fiscal year ended December 29, 2019, as filed with the SEC. Our fiscal year is the 52- or 53-week period ending on the Sunday closest to December 31. In a 52-week year, each fiscal quarter consists of 13 weeks. For ease of disclosure, the 13-week periods are referred to as three-month periods. Our 2020 fiscal year, which ends on January 3, 2021, will contain 53 weeks of operating results, with the additional week occurring in the fourth quarter. Changes in Accounting Standards and Policies There have been no changes in the significant accounting policies from those that were disclosed in the fiscal year 2019 audited consolidated financial statements, other than as noted below. Adoption of Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-13, “Financial Instruments—Credit Losses (Topic 326)”, which replaced the incurred loss methodology for recognizing credit losses with a current expected credit losses model. This standard applied to most financial assets, including trade receivables. Our prior accounts receivable policy is described in detail in our Annual Report on Form 10-K for the year ended December 29, 2019. We adopted the new guidance using a modified retrospective approach as of December 30, 2019, the beginning of fiscal year 2020, and the adoption did not have a material impact on our financial statements and no adjustment was necessary to retained earnings on December 30, 2019. The adoption of the standard resulted in a change in accounting policy for accounts receivable. Our new accounting policy for accounts receivable is presented below. Accounts Receivable We record accounts receivable as our products are received by our customers. Our customers are primarily retailers, distributors and contractors. We record an allowance for credit losses at the time that accounts receivable are initially recorded based on our historical write-off experience and the current economic environment as well as our expectations of future economic conditions. We reassess the allowance at each reporting date. When it becomes apparent, based on age or customer circumstances, that such amounts will not be collected, they are charged to the allowance. Payments subsequently received are credited to the credit loss expense account included within selling, general and administration expenses in the consolidated statements of comprehensive income (loss). Generally, we do not require collateral for our accounts receivable. Other Recent Accounting Pronouncements not yet Adopted In December 2019, the FASB issued ASU 2019-12, "Simplifying the Accounting for Income Taxes," as part of its Simplification Initiative to reduce the cost and complexity in accounting for income taxes. This standard removes certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. It also amends other aspects of the guidance to help simplify and promote consistent application of GAAP. The guidance is effective for interim and annual periods beginning after December 15, 2020, with early adoption permitted. We are in the process of evaluating this guidance to determine the impact it may have on our financial statements. In August 2018, the FASB issued ASU 2018-14, "Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans," which amended ASC 715, "Compensation—Retirement Benefits." This standard is applicable for employers that sponsor defined benefit pension or other postretirement plans, and eliminates disclosures no longer considered cost beneficial, clarifies specific disclosure requirements for entities that provide aggregate disclosures for two or more plans and adds requirements for explanations for significant gains and losses related to changes in benefit obligations. The guidance will be effective for annual periods ending after December 15, 2020; early adoption is permitted and retrospective application is required. We are in the process of evaluating this guidance to determine the impact it may have on our financial statements.