Reinsurance Level 4 Reinsurance Recoverables (Details) - USD ($)	3 Months Ended		4 Months Ended	5 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	May 31, 2018	Sep. 30, 2017	Jun. 01, 2018	Dec. 31, 2017
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reinsurance Recoverables, Including Reinsurance Premium Paid	$ 29,819,000,000		$ 29,819,000,000			$ 22,615,000,000	$ 20,785,000,000
Life Insurance Recoveries on Ceded Reinsurance Contracts	284,000,000	$ 253,000,000	410,000,000	$ 546,000,000	$ 836,000,000
Reinsurance Recoverables, Allowance	0		0				0
Fixed Annuity [Member] | Global Atlantic [Member]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reinsurance Recoverables, Including Reinsurance Premium Paid	9,200,000,000		9,200,000,000
Retirement [Member] | Mass Mutual [Member]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reinsurance Recoverables, Including Reinsurance Premium Paid	8,100,000,000		8,100,000,000				8,300,000,000
Individual Life [Member] | Prudential [Member]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reinsurance Recoverables, Including Reinsurance Premium Paid	11,200,000,000		11,200,000,000				11,100,000,000
Life and Annuity Insurance Product Line [Member] | Fixed Annuity [Member] | Global Atlantic [Member]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reinsurance Recoverables, Including Reinsurance Premium Paid	9,235,000,000		9,235,000,000
Life and Annuity Insurance Product Line [Member] | Retirement Plans and Individual Life Businesses [Member]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reinsurance Recoverables, Including Reinsurance Premium Paid	19,288,000,000		19,288,000,000				19,448,000,000
Life Annuity Accident and Health Insurance Product Line [Member] | Continuing Operations [Member]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reinsurance Recoverables, Including Reinsurance Premium Paid	$ 1,296,000,000		$ 1,296,000,000				$ 1,337,000,000