FDIC Indemnification Asset (Rollforward of the FDIC Indemnification Asset) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Rollforward of the FDIC indemnification asset
FDIC indemnification asset, beginning	$ 22,569us-gaap_FDICIndemnificationAsset
Decrease related to favorable changes in loss estimates	(500)
Increase related to reimbursable expenses	441
Cash received	(2,282)	(9,384)
Related to accretion of loan discount	(1,752)
Other	(24)
FDIC indemnification asset, ending	$ 18,452us-gaap_FDICIndemnificationAsset	$ 35,504us-gaap_FDICIndemnificationAsset

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

- 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.

+ References

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