FDIC Indemnification Asset (Rollforward of the FDIC Indemnification Asset) (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014
Rollforward of the FDIC indemnification asset
FDIC indemnification asset, beginning	$ 22,569
Decrease related to favorable changes in loss estimates	(2,526)
Increase related to reimbursable expenses	1,031
Cash received	(8,758)	$ (16,810)
Decrease related to accretion of loan discount	(4,558)
Decrease related to settlement of disputed claims	(406)
Other	297
FDIC indemnification asset, ending	$ 7,649	$ 25,328

Decrease to the indemnification asset due to other activity with the Federal Deposit Insurance Corporation (FDIC).

No definition available.

Name:	fbp_FDICIndeminficationAssetOtherActivity
Namespace Prefix:	fbp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Decrease to the indemnification asset due to accretion of the loan discount relating to loss sharing agreements with the Federal Deposit Insurance Corporation (FDIC).

+ References

No definition available.

+ Details

Name:	fbp_FDICIndemnificationAssetAccretionOfDiscount1
Namespace Prefix:	fbp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Change in carrying amount of the indemnification asset relating to reimburseable expenses related to loss sharing agreements with the Federal Deposit Insurance Corporation (FDIC).

+ References

No definition available.

+ Details

Name:	fbp_FDICIndemnificationAssetIncreaseRelatedToReimbursableExpenses
Namespace Prefix:	fbp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of decrease to the indemnification asset due to settlement of disputed claims relating to loss sharing agreements with the Federal Deposit Insurance Corporation (FDIC).

+ References

No definition available.

+ Details

Name:	fbp_FDICIndemnificationAssetSettlementOfDisputedClaims
Namespace Prefix:	fbp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

Name:	fbp_RollforwardOfFdicIndemnificationAssetAbstract
Namespace Prefix:	fbp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount of receivable assets originating from the indemnification agreement with the Federal Deposit Insurance Corporation (FDIC), in which the FDIC is to partially cover losses.

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No definition available.

+ Details

Name:	us-gaap_FDICIndemnificationAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of increases to the indemnification asset due to additional estimated losses assumed by the Federal Deposit Insurance Corporation (FDIC), relating to loss sharing agreements with the FDIC.

+ References

No definition available.

+ Details

Name:	us-gaap_FDICIndemnificationAssetAdditionalEstimatedLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of decreases to the indemnification asset due to cash payments received relating to loss sharing agreements with the Federal Deposit Insurance Corporation (FDIC).

+ References

No definition available.

+ Details

Name:	us-gaap_FDICIndemnificationAssetCashPaymentsReceived
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration