Segment Information (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) Segment
Segment Reporting Information [Line Items]
Number of segments | Segment	3
Life
Segment Reporting Information [Line Items]
Estimated increase (decrease) in total assets due to new methodology	$ 5,000
Annuities
Segment Reporting Information [Line Items]
Estimated increase (decrease) in total assets due to new methodology	2,000
Run-off
Segment Reporting Information [Line Items]
Estimated increase (decrease) in total assets due to new methodology	(3,000)
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Estimated increase (decrease) in total assets due to new methodology	(4,000)
Minimum [Member] | Life
Segment Reporting Information [Line Items]
Estimated increase (decrease) in adjusted earnings due to new methodology	120
Maximum | Life
Segment Reporting Information [Line Items]
Estimated increase (decrease) in adjusted earnings due to new methodology	$ 140