Segment Information (Reconciliation Of Income (Loss) From Operations By Segment To Consolidated Net Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Gain (loss) on early extinguishment of debt, after-tax			$ (42)
Net income (loss)	$ (161)	$ 490	454	$ 1,242
Segment Reconciling Items [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Excluded realized gain (loss), after-tax	(49)	(77)	(492)	(149)
Gain (loss) on early extinguishment of debt, after-tax	(33)		(33)	(18)
Benefit ratio unlocking, after-tax	(2)	33	186	32
Net impact from the Tax Cuts and Jobs Act		32		19
Acquisition and integration costs related to mergers and acquisitions, after tax	(31)	(8)	(80)	(47)
Annuities Segment [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)	169	302	686	844
Retirement Plan Services Segment [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)	44	40	125	125
Life Insurance Segment [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)	(245)	176	79	470
Group Protection Segment [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)	61	63	184	137
Other Operations [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)	$ (75)	$ (71)	$ (201)	$ (171)

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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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