Reinsurance - Reinsurance Recoverables by Range of External Credit Rating and Collateral Level (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 5,449
Allowance for uncollectible reinsurance	(32)
Total reinsurance recoverables	5,417
Fair value of collateral contractually required to meet or exceed carrying value of recoverable
Ceded Credit Risk [Line Items]
Reinsurance recoverables	1,258
Collateral provisions exist that may mitigate risk of credit loss
Ceded Credit Risk [Line Items]
Reinsurance recoverables	3,901
No collateral
Ceded Credit Risk [Line Items]
Reinsurance recoverables	290
Ongoing Operations
Ceded Credit Risk [Line Items]
Reinsurance recoverables	358
Ongoing Operations | Upper-medium grade and higher
Ceded Credit Risk [Line Items]
Reinsurance recoverables	173
Ongoing Operations | Lower-medium grade
Ceded Credit Risk [Line Items]
Reinsurance recoverables	64
Ongoing Operations | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	121
Ongoing Operations | Fair value of collateral contractually required to meet or exceed carrying value of recoverable
Ceded Credit Risk [Line Items]
Reinsurance recoverables	92
Ongoing Operations | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Upper-medium grade and higher
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Lower-medium grade
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	92
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss | Upper-medium grade and higher
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss | Lower-medium grade
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | No collateral
Ceded Credit Risk [Line Items]
Reinsurance recoverables	266
Ongoing Operations | No collateral | Upper-medium grade and higher
Ceded Credit Risk [Line Items]
Reinsurance recoverables	173
Ongoing Operations | No collateral | Lower-medium grade
Ceded Credit Risk [Line Items]
Reinsurance recoverables	64
Ongoing Operations | No collateral | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	29
Acquisition, disposition or runoff activities
Ceded Credit Risk [Line Items]
Reinsurance recoverables	5,091
Acquisition, disposition or runoff activities | Upper-medium grade and higher | Lincoln National Life and Lincoln Life & Annuity of New York
Ceded Credit Risk [Line Items]
Reinsurance recoverables	3,033
Acquisition, disposition or runoff activities | Upper-medium grade and higher | Berkshire
Ceded Credit Risk [Line Items]
Reinsurance recoverables	718
Acquisition, disposition or runoff activities | Upper-medium grade and higher | Prudential Retirement Insurance and Annuity
Ceded Credit Risk [Line Items]
Reinsurance recoverables	625
Acquisition, disposition or runoff activities | Upper-medium grade and higher | Life Insurance Company of North America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	424
Acquisition, disposition or runoff activities | Upper-medium grade and higher | Other
Ceded Credit Risk [Line Items]
Reinsurance recoverables	270
Acquisition, disposition or runoff activities | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	21
Acquisition, disposition or runoff activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable
Ceded Credit Risk [Line Items]
Reinsurance recoverables	1,166
Acquisition, disposition or runoff activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Upper-medium grade and higher | Lincoln National Life and Lincoln Life & Annuity of New York
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or runoff activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Upper-medium grade and higher | Berkshire
Ceded Credit Risk [Line Items]
Reinsurance recoverables	309
Acquisition, disposition or runoff activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Upper-medium grade and higher | Prudential Retirement Insurance and Annuity
Ceded Credit Risk [Line Items]
Reinsurance recoverables	625
Acquisition, disposition or runoff activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Upper-medium grade and higher | Life Insurance Company of North America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or runoff activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Upper-medium grade and higher | Other
Ceded Credit Risk [Line Items]
Reinsurance recoverables	232
Acquisition, disposition or runoff activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or runoff activities | Collateral provisions exist that may mitigate risk of credit loss
Ceded Credit Risk [Line Items]
Reinsurance recoverables	3,901
Acquisition, disposition or runoff activities | Collateral provisions exist that may mitigate risk of credit loss | Upper-medium grade and higher | Lincoln National Life and Lincoln Life & Annuity of New York
Ceded Credit Risk [Line Items]
Reinsurance recoverables	3,033
Acquisition, disposition or runoff activities | Collateral provisions exist that may mitigate risk of credit loss | Upper-medium grade and higher | Berkshire
Ceded Credit Risk [Line Items]
Reinsurance recoverables	409
Acquisition, disposition or runoff activities | Collateral provisions exist that may mitigate risk of credit loss | Upper-medium grade and higher | Prudential Retirement Insurance and Annuity
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or runoff activities | Collateral provisions exist that may mitigate risk of credit loss | Upper-medium grade and higher | Life Insurance Company of North America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	424
Acquisition, disposition or runoff activities | Collateral provisions exist that may mitigate risk of credit loss | Upper-medium grade and higher | Other
Ceded Credit Risk [Line Items]
Reinsurance recoverables	18
Acquisition, disposition or runoff activities | Collateral provisions exist that may mitigate risk of credit loss | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	17
Acquisition, disposition or runoff activities | No collateral
Ceded Credit Risk [Line Items]
Reinsurance recoverables	24
Acquisition, disposition or runoff activities | No collateral | Upper-medium grade and higher | Lincoln National Life and Lincoln Life & Annuity of New York
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or runoff activities | No collateral | Upper-medium grade and higher | Berkshire
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or runoff activities | No collateral | Upper-medium grade and higher | Prudential Retirement Insurance and Annuity
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or runoff activities | No collateral | Upper-medium grade and higher | Life Insurance Company of North America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or runoff activities | No collateral | Upper-medium grade and higher | Other
Ceded Credit Risk [Line Items]
Reinsurance recoverables	20
Acquisition, disposition or runoff activities | No collateral | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 4