Investments (Schedule Of Increase (Decrease) In Payables For Collateral On Investments) (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Increase (decrease) in payables for collateral on investments
Collateral payable for derivative investments	$ 503	$ (297)
Securities pledged under securities lending agreements	68	(80)
Securities pledged under repurchase agreements	6	379
Investments pledged for FHLBI	250	280
Total increase (decrease) in payables for collateral on investments	$ 827	$ 282

- Definition

The net change during the reporting period in the amount of cash that is received related to collateral payable held for derivative instruments.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

The net change during the reporting period in the amount of cash that is received related to securities pledged under reverse repurchase agreements

+ References

No definition available.

+ Details

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- Definition

The net change during the reporting period in the amount of cash that is received related to securities pledged under securities lending agreements.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

The net change during the reporting period in the amount of cash that is received related to securities pledged for Federal Home Loan Bank of Indianapolis.

+ References

No definition available.

+ Details

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- Definition

The increase (decrease) during the reporting period in the amount that is received as security when loaning securities.

+ References

No definition available.

+ Details

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Namespace Prefix:	lnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

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