XML 148 R136.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Employee Benefits- Fair Value of Investments (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Large-cap value | Minimum |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Shares | 100 |  |
Large-cap value | Maximum |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Shares | 160 |  |
International value |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage | 8000.00% |  |
Fixed Income Investments |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage | 8000.00% |  |
Fourth Funds Targets Investments |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage | 6500.00% |  |
GSE certificates |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage | 5000.00% |  |
Large cap value | Minimum |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Shares | 60 |  |
Large cap value | Maximum |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Shares | 70 |  |
Pension Plan |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | $ 253 | $ 228 | $ 283
Pension Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 240 |  |
Pension Plan | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 13 |  |
Pension Plan | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap value |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 12 |  |
Pension Plan | Large-cap value | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 12 |  |
Pension Plan | Large-cap value | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap value | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap growth |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 22 |  |
Pension Plan | Large-cap growth | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 22 |  |
Pension Plan | Large-cap growth | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap growth | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap core |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 17 |  |
Pension Plan | Large-cap core | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 17 |  |
Pension Plan | Large-cap core | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap core | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Mid-cap core |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 15 |  |
Pension Plan | Mid-cap core | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 15 |  |
Pension Plan | Mid-cap core | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Mid-cap core | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Small-cap core |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 16 |  |
Pension Plan | Small-cap core | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 16 |  |
Pension Plan | Small-cap core | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Small-cap core | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | International growth |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 18 |  |
Pension Plan | International growth | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 18 |  |
Pension Plan | International growth | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | International growth | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | International value |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 10 |  |
Pension Plan | International value | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 10 |  |
Pension Plan | International value | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | International value | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Fixed Income Funds, Intermediate Core Plus |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 98 |  |
Pension Plan | Fixed Income Funds, Intermediate Core Plus | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 98 |  |
Pension Plan | Fixed Income Funds, Intermediate Core Plus | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Fixed Income Funds, Intermediate Core Plus | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Company common stock |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 31 |  |
Pension Plan | Company common stock | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 31 |  |
Pension Plan | Company common stock | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Company common stock | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large cap value |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 13 |  |
Pension Plan | Large cap value | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large cap value | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 13 |  |
Pension Plan | Large cap value | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Money market |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 1 |  |
Pension Plan | Money market | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 1 |  |
Pension Plan | Money market | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  |  |
Pension Plan | Money market | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | $ 0 |  |

X
- Definition Defined Benefit Plan, Plan Assets, Shares + References No definition available. + Details
Name: | fbc_DefinedBenefitPlanPlanAssetsShares
Namespace Prefix: | fbc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480482/715-20-55-17 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(02) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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 Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480482/715-20-55-17 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(03) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAssetsCategoryLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of investment to total investment within defined benefit plan asset category. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480482/715-20-55-17 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_DefinedBenefitPlanEquityLargeCapValueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_DefinedBenefitPlanEquityNonUSValueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_FixedIncomeInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_FourthFundsTargetsInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_DefinedBenefitPlanCollectiveTrustEquitySecuritiesLargeCapValueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_DefinedBenefitPlanEquityLargeCapGrowthMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_DefinedBenefitPlanEquityLargeCapCoreMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_DefinedBenefitPlanEquityMidCapCoreMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_DefinedBenefitPlanEquitySmallCapCoreMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_DefinedBenefitPlanEquityNonUSGrowthMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=fbc_DefinedBenefitPlanFixedIncomeIntermediateCorePlusMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DefinedBenefitPlanEquitySecuritiesCommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |