XML 151 R95.htm IDEA: XBRL DOCUMENT
v3.25.2

Mezzanine and Stockholders' Equity - Preferred and Temporary Equity (Details) - USD ($) | 6 Months Ended |  |  |
--- | --- | --- | --- | ---
Jun. 30, 2025 | Dec. 31, 2024 | Jun. 30, 2024 | Dec. 31, 2023
Amount Outstanding |  |  |  |
Preferred stock | $ 503,000,000 | $ 503,000,000 |  |
Common stock | $ 4,000,000 | $ 4,000,000 |  |
Shares Authorized |  |  |  |
Common stock (in shares) | 666,666,666 | 666,666,666 |  |
Shares Issued |  |  |  |
Common stock (in shares) | 422,623,325 | 422,416,178 |  |
Shares Outstanding |  |  |  |
Common stock outstanding (in shares) | 415,353,394 | 414,934,628 |  |
Par Value |  |  |  |
Preferred stock (in usd per share) | $ 0.01 | $ 0.01 | $ 0.01 | $ 0.01
Noncumulative convertible preferred stock (in usd per share) | 0.01 | 0.01 | 0.01 | 0.01
Common stock (in usd per share) | $ 0.01 | $ 0.01 | $ 0.01 | $ 0.01
Noncumulative Series A Preferred Stock |  |  |  |
Amount Outstanding |  |  |  |
Preferred stock | $ 503,000,000 |  |  |
Shares Authorized |  |  |  |
Preferred stock (in shares) | 5,000,000 |  |  |
Shares Issued |  |  |  |
Preferred stock (in shares) | 515,000 |  |  |
Shares Outstanding |  |  |  |
Preferred stock (in shares) | 515,000 |  |  |
Par Value |  |  |  |
Preferred stock (in usd per share) | $ 0.01 |  |  |
Liquidation Preference Per Share |  |  |  |
Preferred stock | $ 1,000 |  |  |
Noncumulative Convertible Preferred Stock Series B |  |  |  |
Amount Outstanding |  |  |  |
Preferred stock | $ 1,000,000 |  |  |
Shares Authorized |  |  |  |
Noncumulative convertible preferred stock (in shares) | 267,062 |  |  |
Shares Issued |  |  |  |
Noncumulative convertible preferred stock (in shares) | 192,062 |  |  |
Shares Outstanding |  |  |  |
Noncumulative convertible preferred stock (in shares) | 750 |  |  |
Par Value |  |  |  |
Noncumulative convertible preferred stock (in usd per share) | $ 0.01 |  |  |
Liquidation Preference Per Share |  |  |  |
Noncumulative convertible preferred stock | $ 0 |  |  |
Noncumulative Convertible Preferred Stock Series C |  |  |  |
Temporary Equity [Line Items] |  |  |  |
Dividend rate percentage | 13.00% |  |  |
Amount Outstanding |  |  |  |
Preferred stock | $ 0 |  |  |
Shares Authorized |  |  |  |
Noncumulative convertible preferred stock (in shares) | 523,369 |  |  |
Shares Issued |  |  |  |
Noncumulative convertible preferred stock (in shares) | 0 |  |  |
Shares Outstanding |  |  |  |
Noncumulative convertible preferred stock (in shares) | 0 |  |  |
Par Value |  |  |  |
Noncumulative convertible preferred stock (in usd per share) | $ 0.01 |  |  |
Liquidation Preference Per Share |  |  |  |
Noncumulative convertible preferred stock | $ 2,000 |  |  |
Non-Voting Common Equivalent Series D |  |  |  |
Amount Outstanding |  |  |  |
Common stock | $ 0 |  |  |
Shares Authorized |  |  |  |
Common stock (in shares) | 315,000 |  |  |
Shares Issued |  |  |  |
Common stock (in shares) | 45 |  |  |
Shares Outstanding |  |  |  |
Common stock outstanding (in shares) | 15 |  |  |
Par Value |  |  |  |
Common stock (in usd per share) | $ 0.01 |  |  |
Liquidation Preference Per Share |  |  |  |
Common stock | $ 0.0001 |  |  |
Preferred Stock A (Par Value: $0.01) |  |  |  |
Temporary Equity [Line Items] |  |  |  |
Dividend rate percentage | 6.375% |  |  |

X
- Definition Common Stock Liquidation Preference, Value + References No definition available. + Details
Name: | fbc_CommonStockLiquidationPreferenceValue
Namespace Prefix: | fbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Temporary Equity And Equity, Amount Outstanding, Value + References No definition available. + Details
Name: | fbc_TemporaryEquityAndEquityAmountOutstandingValueAbstract
Namespace Prefix: | fbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Temporary Equity And Equity, Liquidation Preference + References No definition available. + Details
Name: | fbc_TemporaryEquityAndEquityLiquidationPreferenceAbstract
Namespace Prefix: | fbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Temporary Equity And Equity, Par Value + References No definition available. + Details
Name: | fbc_TemporaryEquityAndEquityParValueAbstract
Namespace Prefix: | fbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Temporary Equity And Equity, Shares Authorized + References No definition available. + Details
Name: | fbc_TemporaryEquityAndEquitySharesAuthorizedAbstract
Namespace Prefix: | fbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Temporary Equity And Equity, Shares Issued + References No definition available. + Details
Name: | fbc_TemporaryEquityAndEquitySharesIssuedAbstract
Namespace Prefix: | fbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Temporary Equity And Equity, Shares Outstanding + References No definition available. + Details
Name: | fbc_TemporaryEquityAndEquitySharesOutstandingAbstract
Namespace Prefix: | fbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Temporary Equity, Dividend Rate, Percentage + References No definition available. + Details
Name: | fbc_TemporaryEquityDividendRatePercentage
Namespace Prefix: | fbc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face amount or stated value per share of common stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(16)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 + Details
Name: | us-gaap_CommonStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.6-05(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-2 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(16)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 + Details
Name: | us-gaap_CommonStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479887/480-10-S45-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (01)(iii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 852 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481372/852-10-55-10 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(22)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
Name: | us-gaap_CommonStockValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The percentage rate used to calculate dividend payments on preferred stock. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.12-12A(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12(Column A)(Footnote 4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-3 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 + Details
Name: | us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of the difference between preference in liquidation and the par or stated values of the preferred shares. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-4 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (h) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-13 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(d)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 + Details
Name: | us-gaap_PreferredStockLiquidationPreferenceValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-13 + Details
Name: | us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(16)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 + Details
Name: | us-gaap_PreferredStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares issued for nonredeemable preferred shares and preferred shares redeemable solely at option of issuer. Includes, but is not limited to, preferred shares issued, repurchased, and held as treasury shares. Excludes preferred shares classified as debt. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-13 + Details
Name: | us-gaap_PreferredStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.6-05(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(16)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 + Details
Name: | us-gaap_PreferredStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate par or stated value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479887/480-10-S45-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (01)(ii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 852 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481372/852-10-55-10 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(21)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
Name: | us-gaap_PreferredStockValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479857/480-10-S50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479857/480-10-S50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479887/480-10-S45-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-1 + Details
Name: | us-gaap_TemporaryEquityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate liquidation preference (or restrictions) of stock classified as temporary equity that has a preference in involuntary liquidation considerably in excess of the par or stated value of the shares. The liquidation preference is the difference between the preference in liquidation and the par or stated values of the share. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. + References No definition available. + Details
Name: | us-gaap_TemporaryEquityLiquidationPreference
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Per share amount of par value or stated value of stock classified as temporary equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_TemporaryEquityParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of securities classified as temporary equity that are permitted to be issued by an entity's charter and bylaws. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479857/480-10-S50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_TemporaryEquitySharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of securities classified as temporary equity that have been sold (or granted) to the entity's shareholders. Securities issued include securities outstanding and securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479857/480-10-S50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_TemporaryEquitySharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479857/480-10-S50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_TemporaryEquitySharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=fbc_NoncumulativePreferredStockSeriesAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=fbc_NoncumulativeConvertiblePreferredStockSeriesBMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=fbc_NoncumulativeConvertiblePreferredStockSeriesCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=fbc_NonVotingCommonEquivalentStockSeriesDMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_PreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |