| Cover page - USD ($) | 12 Months Ended | ||
| Dec. 31, 2019 | Apr. 15, 2020 | Jun. 28, 2019 | |
| Cover [Abstract] | |||
| Document Type | 10-K/A | ||
| Document Annual Report | true | ||
| Document Period End Date | Dec. 31, 2019 | ||
| Document Transition Report | false | ||
| Entity File Number | 001-12111 | ||
| Entity Registrant Name | MEDNAX, INC. | ||
| Entity Central Index Key | 0000893949 | ||
| Current Fiscal Year End Date | --12-31 | ||
| Document Fiscal Year Focus | 2019 | ||
| Document Fiscal Period Focus | FY | ||
| Amendment Flag | true | ||
| Entity Incorporation, State or Country Code | FL | ||
| Entity Tax Identification Number | 26-3667538 | ||
| Entity Address, Address Line One | 1301 Concord Terrace | ||
| Entity Address, City or Town | Sunrise | ||
| Entity Address, State or Province | FL | ||
| Entity Address, Postal Zip Code | 33323 | ||
| City Area Code | 954 | ||
| Local Phone Number | 384-0175 | ||
| Title of 12(b) Security | Common Stock, par value $.01 per share | ||
| Trading Symbol | MD | ||
| Security Exchange Name | NYSE | ||
| Entity Well-known Seasoned Issuer | Yes | ||
| Entity Voluntary Filers | No | ||
| Entity Current Reporting Status | Yes | ||
| Entity Interactive Data Current | Yes | ||
| Entity Filer Category | Large Accelerated Filer | ||
| Entity Small Business | false | ||
| Entity Emerging Growth Company | false | ||
| Entity Shell Company | false | ||
| Entity Public Float | $ 2,051,190,371 | ||
| Entity Common Stock, Shares Outstanding | 85,412,375 | ||
| Amendment Description | On February 20, 2020, MEDNAX, Inc., a Florida corporation (the “Company”), filed its Annual Report on Form 10-K for the fiscal year ended December 31, 2019 (the “Original Form 10-K”). The Company is filing this Amendment No. 1 on Form 10-K/A (the “Form 10-K/A”) in order to include the information required by Items 10 through 14 for Form 10-K. This information was previously omitted from the Original Form 10-K consistent with General Instruction G(3) to Form 10-K. The Company is filing the Form 10-K/A to provide the information required in Part III of Form 10-K for purposes of incorporating that information by reference into other filings with the Securities and Exchange Commission (the “SEC”). This Form 10-K/A amends and restates in its entirety Part III, Items 10 through 14 of the Original Form 10-K, to include information previously omitted from the Original Form 10-K consistent with General Instruction G(3) to Form 10-K. The reference on the cover page of the Original Form 10-K to the incorporation by reference of portions of the Company’s definitive proxy statement into Part III of the Original Form 10-K is hereby deleted. In this Form 10-K/A, the terms “MEDNAX,” the “Company,” “we,” “us” and “our” refer to the parent company, MEDNAX, Inc., a Florida corporation, and the consolidated subsidiaries through which its businesses are actually conducted (collectively, “MDX”), together with MDX’s affiliated business corporations or professional associations, professional corporations, limited liability companies and partnerships (“affiliated professional contractors”). Certain subsidiaries of MDX have contracts with our affiliated professional contractors, which are separate legal entities that provide physician services in certain states and Puerto Rico.In addition, as required by Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), certifications by the Company’s principal executive officer and principal financial officer are filed as exhibits to this Form 10-K/A under Item 15 of Part IV hereof. Because no financial statements have been included in this Form 10-K/A and this Form 10-K/A does not contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4 and 5 of the certifications have been omitted. We are not including the certifications under Section 906 of the Sarbanes-Oxley Act of 2002 as no financial statements are being filed with this Form 10-K/A. Except as described above, this Form 10-K/A does not modify or update disclosure in, or exhibits to, the Original Form 10-K. Furthermore, this Form 10-K/A does not change any previously reported financial results, nor does it reflect events occurring after the date of the Original Form 10-K. Information not affected by this Form 10-K/A remains unchanged and reflects the disclosures made at the time the Original Form 10-K was filed. Accordingly, this Form 10-K/A should be read in conjunction with the Original Form 10-K and our other filings with the SEC. |
