Investments (Mortgage Loans - Narrative) (Details) $ in Thousands	3 Months Ended
Mar. 31, 2017 USD ($)	Mar. 31, 2016	Dec. 31, 2016 USD ($)
Financing Receivable, Recorded Investment [Line Items]
Carrying Value	$ 0		$ 0
Recorded Investment	$ 0		$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	0
Percentage of Mortgage Loans Classified as Performing	100.00%		100.00%
Financing Receivable Number of Contract of Recorded Investment Past Due	0		0
Loans and Leases Receivable, Number of Contract, Nonperforming, Nonaccrual of Interest	0		0

Reflects the number of financing receivables of recorded investment that are past due at the balance sheet date.

No definition available.

Name:	bhny_FinancingReceivableNumberofContractofRecordedInvestmentPastDue
Namespace Prefix:	bhny_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Reflects the number of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

+ References

No definition available.

+ Details

Name:	bhny_LoansAndLeasesReceivableNumberOfContractNonperformingNonaccrualOfInterest
Namespace Prefix:	bhny_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The percentage of all mortgage loans that are classified as performing.

+ References

No definition available.

+ Details

Name:	bhny_PercentageOfMortgageLoansClassifiedAsPerforming
Namespace Prefix:	bhny_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

+ Details

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

- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953550-111524

+ Details

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