Name:	cik0000726865_DeferredSalesInducementsAmortizationExpenseNetAbstract
Namespace Prefix:	cik0000726865_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of amortization of deferred sales inducement costs attributable to realized investment gains (losses).

No definition available.

Name:	cik0000726865_DeferredSalesInducementsAmortizationExpenseNetInvestmentGainsLosses
Namespace Prefix:	cik0000726865_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of amortization of deferred sales inducement costs attributable to unrealized investment gains (losses).

No definition available.

Name:	cik0000726865_DeferredSalesInducementsAmortizationExpenseUnrealizedInvestmentGainsLosses
Namespace Prefix:	cik0000726865_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of adjustment to amortization of deferred sales inducement costs arising from a revision in estimated gross profit (when such amount serves as the basis for allocating amortization of DSI to reporting periods).

No definition available.

Name:	cik0000726865_DeferredSalesInducementsNetAmortizationExpenseEffectOfAdjustmentsToEstimatedGrossProfit
Namespace Prefix:	cik0000726865_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of other amortization of deferred sales inducement costs, net of interest, during the period.

No definition available.

Name:	cik0000726865_DeferredSalesInducementsNetAmortizationExpenseOtherAmortizationNetOfInterest
Namespace Prefix:	cik0000726865_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of addition in deferred sales inducement cost.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6481800&loc=d3e11332-158416

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

Amount, after accumulated amortization, of deferred sales inducement cost.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6481654&loc=d3e11214-158414

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6481800&loc=d3e11332-158416

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

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.