Noncontrolling Interests Redeemable Noncontrolilng Interests Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests at beginning of period			$ 18,088
Nonredeemable Noncontrolling Interest at beginning of period			3,393
Net income attributable to noncontrolling interests	$ 989	$ 1,263	1,900	$ 2,492
Redeemable noncontrolling interests at end of period	15,843		15,843
Nonredeemable Noncontrolling Interest at end of period	3,379		3,379
Redeemable Noncontrolling Interest [Member]
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests at beginning of period	16,938	19,911	18,088	20,905
Net income attributable to noncontrolling interests	769	984	1,487	2,064
Redeemable noncontrolling interest, decrease from distributions to redeemable noncontrolling interest holders	(788)	(1,098)	(1,404)	(2,153)
Redeemable Noncontrolling Interest Increase, Purchase of Additional Ownership Interest	(908)	(1,503)	(766)	(1,503)
Noncontrolling Interest, Increase from Subsidiary Equity Issuance		0		(1,652)
Amortization of Noncontrolling Interest Equity Compensation	76	0	187	0
Noncontrolling Interest, adjustment to fair value	(244)	906	(1,749)	1,539
Redeemable noncontrolling interests at end of period	15,843	19,200	15,843	19,200
Noncontrolling Interest [Member]
Redeemable Noncontrolling Interest [Line Items]
Nonredeemable Noncontrolling Interest at beginning of period	3,116	2,601	3,393	386
Net income attributable to noncontrolling interests	220	279	413	428
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(198)	(116)	(440)	(252)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	(18)	0	(18)	419
Noncontrolling Interest, Increase from Subsidiary Equity Issuance		0		1,652
Amortization of Noncontrolling Interest Equity Compensation	132	118	264	236
Noncontrolling Interest, adjustment to fair value	127	14	(233)	27
Nonredeemable Noncontrolling Interest at end of period	$ 3,379	$ 2,896	$ 3,379	$ 2,896

Amortization of Noncontrolling Interest Equity Compensation

No definition available.

Name:	bpfh_AmortizationofNoncontrollingInterestEquityCompensation
Namespace Prefix:	bpfh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Redeemable Noncontrolling Interest Increase, Purchase or (Sale) of Additional Ownership Interest - Increase in balance of noncontrolling interest due to purchase of additional interest in subsidiary.

+ References

No definition available.

+ Details

Name:	bpfh_RedeemableNoncontrollingInterestIncreasePurchaseorSaleofAdditionalOwnershipInterest
Namespace Prefix:	bpfh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Decrease in redeemable noncontrolling interest balance from payment of dividends or other distributions to redeemable noncontrolling interest holders

+ References

No definition available.

+ Details

Name:	bpfh_Redeemablenoncontrollinginterestdecreasefromdistributionstoredeemablenoncontrollinginterestholders
Namespace Prefix:	bpfh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders.

+ References

+ Details

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

- Definition

Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=51664549&loc=SL4569655-111683

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 24
-URI http://asc.fasb.org/extlink&oid=51664549&loc=SL4616395-111683

+ Details

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

- Definition

Net Increase or Decrease in balance of noncontrolling interest in the subsidiary during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=51664549&loc=SL4568740-111683

+ Details

Name:	us-gaap_MinorityInterestPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of Net Income (Loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4J
-URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591551-111686

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

+ Details

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

- Definition

Amount of increase in noncontrolling interest from subsidiary issuance of equity interests to noncontrolling interest holders.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=51664549&loc=SL4569655-111683

+ Details

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

- Definition

Portion of equity (net assets) in a subsidiary not attributable, directly or indirectly, to the parent entity which is not redeemable by the parent entity.

+ References

No definition available.

+ Details

Name:	us-gaap_NonredeemableNoncontrollingInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph (12)(c)
-URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph (16)(c)
-URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph 15
-URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph 14
-URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764

+ Details

Name:	us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

No definition available.

+ Details

Name:	us-gaap_RedeemableNoncontrollingInterestLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementEquityComponentsAxis=bpfh_RedeemableNoncontrollingInterestMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_NoncontrollingInterestMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: