Accounting Changes and Error Corrections (Policies)	9 Months Ended
Accounting Changes and Error Corrections (Policies)	Sep. 30, 2020
Accounting Changes and Error Corrections [Abstract]
Basis of Presentation	The accompanying consolidated financial statements are unaudited. AMETEK, Inc. (the “Company”) believes that all adjustments (which primarily consist of normal recurring accruals) necessary for a fair presentation of the consolidated financial position of the Company at September 30, 2020, the consolidated results of its operations for the three and nine months ended September 30, 2020 and 2019 and its cash flows for the nine months ended September 30, 2020 and 2019 have been included. Quarterly results of operations are not necessarily indicative of results for the full year. The accompanying consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes presented in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 as filed with the U.S. Securities and Exchange Commission.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements Effective January 1, 2020, the Company adopted ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), using the modified retrospective transition method. ASU 2016-13 provides guidance on the estimation of current expected credit losses on financial instruments, including trade receivables. ASU 2016-13 requires entities to consider a broad range of information to estimate expected credit losses, including increased forward-looking information, which may result in earlier recognition of losses when compared to prior standards. The adoption of ASU 2016-13 was a decrease to net Accounts Receivable and a decrease to Retained Earnings of $0.4 million. See Note 3 - Revenues, for further discussion. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (“ASU 2018-13”), which changes the fair value measurement disclosure requirements of ASC Topic 820, Fair Value Measurement (“ASC 820”), by eliminating, modifying and adding to those requirements. ASU 2018-13 also modifies the disclosure objective paragraphs of ASC 820 to eliminate (1) “at a minimum” from the phrase “an entity shall disclose at a minimum” and (2) other similar “open ended” disclosure requirements to promote the appropriate exercise of discretion by entities. The Company prospectively adopted ASU 2018-13, effective January 1, 2020, and the adoption did not have a significant impact on the Company’s consolidated results of operations, financial position, cash flows and financial statement disclosures. In August 2018, the FASB issued ASU No. 2018-15, Intangibles–Goodwill and Other–Internal-Use Software (“ASU 2018-15”), that requires implementation costs incurred by customers in cloud computing arrangements to be deferred and recognized over the term of the arrangement, if those costs would be capitalized by the customer in a software licensing arrangement under the internal-use software guidance in ASC Topic 350, Intangibles–Goodwill and Other. ASU 2018-15 requires a customer to disclose the nature of its hosting arrangements that are service contracts and provide disclosures as if the deferred implementation costs were a separate, major depreciable asset class. The Company prospectively adopted ASU 2018-15, effective January 1, 2020, and the adoption did not have a significant impact on the Company’s consolidated results of operations, financial position, cash flows and financial statement disclosures. Recent Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC Topic 740. ASU 2019-12 is effective for fiscal years beginning after December 15, 2021. Early adoption is permitted and the amendments in this ASU should be applied on a retrospective basis to all periods presented. The Company has not determined the impact ASU 2019-12 may have on the Company’s consolidated results of operations, financial position, cash flows or financial statement disclosures. In August 2018, the FASB issued ASU No. 2018-14, Compensation–Retirement Benefits–Defined Benefit Plans–General (“ASU 2018-14”), which changes the disclosure requirements of ASC Topic 715, Compensation – Retirement Benefits, by eliminating, modifying and adding to those requirements. ASU 2018-14 is effective for fiscal years beginning after December 15, 2020. Early adoption is permitted and the amendments in this ASU should be applied on a retrospective basis to all periods presented. The Company has not determined the impact ASU 2018-14 may have on the Company’s consolidated financial statement disclosures.
Accounts Receivable	Accounts Receivable The Company maintains allowances for estimated losses resulting from the inability of customers to meet their financial obligations to the Company. The Company recognizes an allowance for doubtful accounts, on all accounts receivable, which considers the length of time receivables are past due, customers’ billing exposure, ability to pay, and contract terms. The Company also considers general and market business conditions, country, and political risk. Balances are written off when determined to be uncollectible. At September 30, 2020, the Company recorded $614.8 million of accounts and notes receivable, net of allowances of $12.6 million. Changes in the allowance were not material for the three and nine months ended September 30, 2020.