Goodwill and Specifically Identifiable Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Goodwill Gross		$ 3,522	$ 3,522
Accumulated impairment as of beginning-of-year		(1,249)	(1,249)
Impairment
Net goodwill as of end-of-year	2,273	2,273
Annuities Segment [Member]
Goodwill [Roll Forward]
Goodwill Gross		1,040	1,040
Accumulated impairment as of beginning-of-year		(600)	(600)
Impairment
Net goodwill as of end-of-year	440	440
Retirement Plan Services Segment [Member]
Goodwill [Roll Forward]
Goodwill Gross		20	20
Impairment
Net goodwill as of end-of-year	20	20
Life Insurance Segment [Member]
Goodwill [Roll Forward]
Goodwill Gross		2,188	2,188
Accumulated impairment as of beginning-of-year		(649)	(649)
Impairment
Net goodwill as of end-of-year	1,539	1,539
Group Protection Segment [Member]
Goodwill [Roll Forward]
Goodwill Gross		274	$ 274
Impairment
Net goodwill as of end-of-year	$ 274	$ 274