Summary of Significant Accounting Policies	3 Months Ended
Mar. 28, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations Entegris, Inc. (Entegris or the Company) is a leading provider of yield-enhancing materials and solutions for advanced manufacturing processes in the semiconductor and other high-technology industries. Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its majority-owned subsidiaries. Intercompany profits, transactions and balances have been eliminated in consolidation. Use of Estimates The preparation of condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, particularly receivables, inventories, property, plant and equipment, goodwill, intangibles, accrued expenses, and income taxes and related accounts, and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States and contain all adjustments considered necessary, and are of a normal recurring nature, to present fairly the financial position as of March 28, 2015 and December 31, 2014, and the results of operations, comprehensive income, equity and cash flows for the three months ended March 28, 2015 and March 29, 2014. The condensed consolidated financial statements and notes are presented as permitted by Form 10-Q and do not contain certain information included in the Company’s annual consolidated financial statements and notes. The information included in this Form 10-Q should be read in conjunction with Management’s Discussion and Analysis and consolidated financial statements and notes thereto included in the Company’s Form 10-K for the year ended December 31, 2014. The results of operations for the three months ended March 28, 2015 are not necessarily indicative of the results to be expected for the full year. Fair Value of Financial Instruments The carrying value of cash equivalents, accounts receivable, accounts payable, accrued payroll and related benefits, and other accrued liabilities approximates fair value due to the short maturity of those instruments. The fair value of long-term debt, including current maturities, based upon models utilizing market observable (Level 2) inputs and credit risk, was $757.2 million at March 28, 2015 compared to the carrying amount of long-term debt, including current maturities, of $741.9 million. Recent Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606)(ASU 2014-09). ASU 2014-09 outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This new revenue recognition model provides a five-step analysis in determining when and how revenue is recognized. The new model will require revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration a company expects to receive in exchange for those goods or services. ASU 2014-09 is effective beginning January 1, 2017. The Company is currently assessing the impact that adopting this new accounting guidance will have on its consolidated financial statements and disclosures. On April 7, 2015, the FASB issued Accounting Standards Update No. 2015-03, Simplifying the Presentation of Debt Issuance Costs (ASU No. 2015-03) which requires an entity to present debt issuance costs as a direct deduction from the carrying amount of the related debt liability on the balance sheet. The update requires retrospective application and represents a change in accounting principle. The update becomes effective January 1, 2016. Based on the balances as of March 28, 2015, the adoption of ASU No. 2015-03 will require the Company to reclassify $14.3 million of unamortized debt issuance costs from other current assets and other noncurrent assets to long-term debt.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Nature of Operations Entegris, Inc. (Entegris or the Company) is a leading provider of yield-enhancing materials and solutions for advanced manufacturing processes in the semiconductor and other high-technology industries.

Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its majority-owned subsidiaries. Intercompany profits, transactions and balances have been eliminated in consolidation.

Use of Estimates The preparation of condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, particularly receivables, inventories, property, plant and equipment, goodwill, intangibles, accrued expenses, and income taxes and related accounts, and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States and contain all adjustments considered necessary, and are of a normal recurring nature, to present fairly the financial position as of March 28, 2015 and December 31, 2014, and the results of operations, comprehensive income, equity and cash flows for the three months ended March 28, 2015 and March 29, 2014.

The condensed consolidated financial statements and notes are presented as permitted by Form 10-Q and do not contain certain information included in the Company’s annual consolidated financial statements and notes. The information included in this Form 10-Q should be read in conjunction with Management’s Discussion and Analysis and consolidated financial statements and notes thereto included in the Company’s Form 10-K for the year ended December 31, 2014. The results of operations for the three months ended March 28, 2015 are not necessarily indicative of the results to be expected for the full year.

Fair Value of Financial Instruments The carrying value of cash equivalents, accounts receivable, accounts payable, accrued payroll and related benefits, and other accrued liabilities approximates fair value due to the short maturity of those instruments. The fair value of long-term debt, including current maturities, based upon models utilizing market observable (Level 2) inputs and credit risk, was $757.2 million at March 28, 2015 compared to the carrying amount of long-term debt, including current maturities, of $741.9 million.

Recent Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606)(ASU 2014-09). ASU 2014-09 outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This new revenue recognition model provides a five-step analysis in determining when and how revenue is recognized. The new model will require revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration a company expects to receive in exchange for those goods or services. ASU 2014-09 is effective beginning January 1, 2017. The Company is currently assessing the impact that adopting this new accounting guidance will have on its consolidated financial statements and disclosures.

On April 7, 2015, the FASB issued Accounting Standards Update No. 2015-03, Simplifying the Presentation of Debt Issuance Costs (ASU No. 2015-03) which requires an entity to present debt issuance costs as a direct deduction from the carrying amount of the related debt liability on the balance sheet. The update requires retrospective application and represents a change in accounting principle. The update becomes effective January 1, 2016. Based on the balances as of March 28, 2015, the adoption of ASU No. 2015-03 will require the Company to reclassify $14.3 million of unamortized debt issuance costs from other current assets and other noncurrent assets to long-term debt.