XML 51 R41.htm IDEA: XBRL DOCUMENT
v3.21.2

Securities - Additional Information (Details) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2021 USD ($) Investment | Sep. 30, 2020 USD ($) | Dec. 31, 2020 USD ($) Investment
Schedule of Investments [Line Items] |  |  |  |  |
Federal Home Loan Bank stock, at cost | $ | $ 684 | [1] |  | $ 714 | [2]
Net losses on equity securities | $ | $ 0 |  | $ 0 |  |
Collateralized Mortgage Obligations |  |  |  |  |
Schedule of Investments [Line Items] |  |  |  |  |
Number of investment securities designated as having a continuous loss position for twelve months or more |  |  |  | 4 |
Capital Trust Notes |  |  |  |  |
Schedule of Investments [Line Items] |  |  |  |  |
Number of investment securities designated as having a continuous loss position for twelve months or more | 5 |  |  | 5 |
Asset-backed Securities |  |  |  |  |
Schedule of Investments [Line Items] |  |  |  |  |
Number of investment securities designated as having a continuous loss position for twelve months or more | 4 |  |  | 7 |
Corporate Bonds |  |  |  |  |
Schedule of Investments [Line Items] |  |  |  |  |
Number of investment securities designated as having a continuous loss position for twelve months or more | 4 |  |  | 3 |
U.S. Government Agency Obligations |  |  |  |  |
Schedule of Investments [Line Items] |  |  |  |  |
Number of investment securities designated as having a continuous loss position for twelve months or more | 8 |  |  |  |
Municipal Bonds |  |  |  |  |
Schedule of Investments [Line Items] |  |  |  |  |
Number of investment securities designated as having a continuous loss position for twelve months or more | 1 |  |  | 1 |
[1] | Carrying value and estimated fair value are at cost.
[2] | Carrying value and estimated fair value are at cost.

X
- Definition Number of Securities, Continuous Unrealized Loss Position More Than Twelve Months + References No definition available. + Details
Name: | nycb_NumberOfSecuritiesContinuousUnrealizedLossPositionMoreThanTwelveMonths
Namespace Prefix: | nycb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=120269885&loc=SL75117546-209714 + Details
Name: | us-gaap_EquitySecuritiesFvNiGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 325 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=75031641&loc=d3e63345-112809 + Details
Name: | us-gaap_FederalHomeLoanBankStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CollateralizedDebtObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CorporateNoteSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |