Investments - Scheduled maturities of available for sale fixed maturities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Percent, Fiscal Year Maturity [Abstract]
Average life of CLOs and Other ABS	4 years
Average life of MBS	4 years 6 months
Securities With Non-Credit Other Than Temporary Impairment Charges [Member]
Fair Value Percent, Fiscal Year Maturity [Abstract]
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	$ (1)	$ (4)
Fixed maturities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
One year or less	1,764
After one year through five years	10,613
After five years through ten years	13,513
After ten years	3,539
Fixed maturities amortized cost, Subtotal	29,429
Collateralized loan obligations and other ABS (average life of approximately 4 years)	11,299
MBS (average life of approximately 4-1/2 years)	3,796
Amortized Cost	44,524
Fair Value, Fiscal Year Maturity [Abstract]
One year or less	1,793
After one year through five years	11,044
After five years through ten years	14,419
After ten years	3,754
Fixed maturities fair value, Subtotal	31,010
Collateralized loan obligations and other ABS (average life of approximately 4 years)	11,408
MBS (average life of approximately 4-1/2 years)	4,087
Fair Value	$ 46,505
Fair Value Percent, Fiscal Year Maturity [Abstract]
One year or less	4.00%
After one year through five years	24.00%
After five years through ten years	31.00%
After ten years	8.00%
Fixed maturities fair value, Subtotal, Percent	67.00%
Collateralized loan obligations and other ABS (average life of approximately 4 years)	24.00%
MBS (average life of approximately 4-1/2 years)	9.00%
Fair value, Total, Percent	100.00%