| Cover page - USD ($) $ in Billions | 12 Months Ended | ||
| Dec. 31, 2019 | May 13, 2020 | Jun. 30, 2019 | |
| Document Information [Line Items] | |||
| Amendment Flag | true | ||
| Document Type | 10-K/A | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| Document Fiscal Year Focus | 2019 | ||
| Document Fiscal Period Focus | FY | ||
| Document Period End Date | Dec. 31, 2019 | ||
| Entity Central Index Key | 0000910073 | ||
| Current Fiscal Year End Date | --12-31 | ||
| Entity Registrant Name | NEW YORK COMMUNITY BANCORP INC | ||
| Entity Current Reporting Status | Yes | ||
| Entity Filer Category | Large Accelerated Filer | ||
| Entity Emerging Growth Company | false | ||
| Entity Well-known Seasoned Issuer | Yes | ||
| Entity Small Business | false | ||
| Entity Voluntary Filers | No | ||
| Entity Public Float | $ 4.5 | ||
| Entity Shell Company | false | ||
| Entity Common Stock, Shares Outstanding | 463,937,039 | ||
| Entity Interactive Data Current | Yes | ||
| Entity File Number | 1-31565 | ||
| Entity Incorporation, State or Country Code | DE | ||
| City Area Code | 516 | ||
| Local Phone Number | 683-4100 | ||
| Entity Tax Identification Number | 06-1377322 | ||
| Entity Address, Address Line One | 615 Merrick Avenue | ||
| Entity Address, City or Town | Westbury | ||
| Entity Address, State or Province | NY | ||
| Entity Address, Postal Zip Code | 11590 | ||
| Amendment Description | New York Community Bancorp Inc. (the “Company”) is filing this Amendment No. 1 on Form 10-K/A (this “Amendment No. 1”) to amend the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, which was initially filed with the U.S. Securities and Exchange Commission (the “SEC”) on February 28, 2020 (the “Original 2019 Form 10-K”). The purpose of this Amendment No. 1 is to provide the Consulting Agreement between the Company and James J. Carpenter under Exhibit 10.16, which was inadvertently omitted from the Original 2019 Form 10-K. In addition, pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), new certifications by the Company’s principal executive officer and principal financial officer are filed herewith as exhibits to this Amendment No. 1 pursuant to Rule 13a-14(a) or 15d-14(a) of the Exchange Act. These certifications are attached to this Amendment No. 1 as Exhibits 31.1 and 31.2. Because no financial statements have been included in this Amendment No. 1 and this Amendment No. 1 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. Additionally, we are not including the certificate under Section 906 of the Sarbanes-Oxley Act of 2002, as no financial statements are being filed with this Amendment No. 1. This Amendment No. 1 is an exhibit-only filing. Except as described above, this Amendment No. 1 does not modify or update in any way the financial statements or disclosures made, or any exhibits included or incorporated by reference, in the Original 2019 Form 10-K and does not reflect events occurring after the filing of the Original 2019 Form 10-K. Accordingly, this Amendment No. 1 should be read in conjunction with the Original 2019 Form 10-K and the Company’s other filings with the SEC. | ||
| Common Stock [Member] | |||
| Document Information [Line Items] | |||
| Title of 12(b) Security | Common Stock | ||
| Trading Symbol | NYCB | ||
| Security Exchange Name | NYSE | ||
| Bifurcated Option Note Unit Securities [Member] | |||
| Document Information [Line Items] | |||
| Title of 12(b) Security | Bifurcated Option Note Unit SecuritiESSM | ||
| Trading Symbol | NYCB PU | ||
| Security Exchange Name | NYSE | ||
| Fixed to Floating Rate Series A Noncumulative Perpetual Preferred Stock [Member] | |||
| Document Information [Line Items] | |||
| Title of 12(b) Security | Depositary Shares each representing | ||
| Trading Symbol | NYCB PA | ||
| Security Exchange Name | NYSE |
