Name:	fbc_RepresentationAndWarrantyReserve
Namespace Prefix:	fbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount represents the increase in the representation and warranty reserve related to estimated expected mortgage loan repurchase losses related to new sales.

No definition available.

Name:	fbc_RepresentationAndWarrantyReserveAdditionNewSales
Namespace Prefix:	fbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The total provision of estimate of expected losses for the reserve for the expected losses related to loans sold into the secondary mortgage market that may be required to repurchase.

No definition available.

Name:	fbc_RepresentationAndWarrantyReserveAdditions
Namespace Prefix:	fbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The charge-offs represent the actual loss incurred upon completion of processing approved repurchase where the entity has agreed to repurchase the loan and/or indemnify the investor.

No definition available.

Name:	fbc_RepresentationAndWarrantyReserveReductionChargeOffs
Namespace Prefix:	fbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Tabular disclosure of an entity's representation and warranty reserve that occurred during the period to encapsulate the roll forward presentations of an entity's representation and warranty reserve by type of cost and in total, and explanation of changes that occurred in the period.

No definition available.

Name:	fbc_RepresentationAndWarrantyReserveRollForward
Namespace Prefix:	fbc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of representation and warrant reserve for the expected losses related to loans that may be required to repurchase (or the indemnity payments we may have to make to purchasers) and account adjustments to previous estimates of expected losses on loans sold.

No definition available.