Investments (Investment in Leverage Leases) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Investment in leveraged leases
Rental receivables, net	$ 87	$ 90
Estimated residual values	14	14
Subtotal	101	104
Unearned income	(32)	(33)
Investment in leveraged leases, net of non-recourse debt	$ 69	$ 71

This element represents the subtotal of rental receivables, net plus estimated residual value of the leased assets.

No definition available.

Name:	bhl_InvestmentInLeveragedLeases
Namespace Prefix:	bhl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The estimated portion of pretax income and investment tax credit remaining to be allocated to income over the lease term.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=7662307&loc=d3e42840-112730

+ Details

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

- Definition

The net investment in arrangements meeting the criteria for classification as leveraged leases including deferred taxes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=7662307&loc=d3e42840-112730

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 35
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=7662473&loc=d3e43930-112732

+ Details

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

- References

No definition available.

+ Details

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

- Definition

This element represents leveraged lease rentals receivable, net of that portion of the rental applicable to principal and interest on the nonrecourse debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=7662307&loc=d3e42840-112730

+ Details

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

- Definition

The estimate of the value of the leased asset at the end of the lease term.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=7662307&loc=d3e42840-112730

+ Details

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