Income Tax (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets, Valuation Allowance	$ 294	$ 302	$ 294	$ 302
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Policyholder Liabilities	3,635	3,558	3,635	3,558
Deferred Tax Assets, Other	127	365	127	365
Deferred Tax Liabilities, Investments	4,170	3,854	4,170	3,854
Deferred Tax Assets, Operating Loss Carryforwards	240	237	240	237
Income Tax Expense (Benefit)			886	1,179	$ (1,470)
Operating Expenses			13,689	13,714	13,621
Tax Credit Carryforward, Amount	1,296	1,113	1,296	1,113
Deferred Federal Income Tax Expense (Benefit)			(235)	342	(2,373)
Settlement with Taxing Authority
Tax Adjustments, Settlements, and Unusual Provisions	(226)	(349)
Income Tax Expense (Benefit)	(158)	(168)
Operating Expenses	86	229
Operating Expenses Net	68	181
Certain State and Foreign Net Operating Loss Carryforwards
Valuation allowance, change during year			240
Restatement Adjustment
Deferred Tax Assets, Valuation Allowance		133		133
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Policyholder Liabilities		671		671
Deferred Tax Assets, Other		173		173
Deferred Tax Liabilities, Investments		1,400		1,400
Deferred Tax Liabilities, Other		495		495
Deferred Tax Assets, Operating Loss Carryforwards		$ 133		133
Impact of U.S. Tax Reform
Income Tax Expense (Benefit)			(326)	66	(1,620)
Deferred Federal Income Tax Expense (Benefit)			(9)	(402)	(1,790)
Impact of U.S. Tax Reform | GILTI [Member]
Effective Income Tax Rate Reconciliation, Tax Contingency, Foreign, Amount			12
Income Tax Expense (Benefit)			35	45
Compensation and fringe benefits
Deferred Federal Income Tax Expense (Benefit)			0	$ 0	$ 8
General Business Tax Credit Carryforward [Member] | 2036and2039 [Member]
Tax Credit Carryforward, Amount	113		113
Other Assets
Deferred Tax Assets, Net	$ 65		$ 65