Goodwill and Specifically Identifiable Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Roll Forward]
Acquisition balance as of beginning-of-year	$ 2,273	$ 3,863
Cumulative impairment as of beginning-of-year	(1,590)	(1,590)
Impairment
Balance as of end-of-year	2,273	2,273
Annuities [Member]
Goodwill [Roll Forward]
Acquisition balance as of beginning-of-year	440	1,040
Cumulative impairment as of beginning-of-year	(600)	(600)
Impairment
Balance as of end-of-year	440	440
Retirement Plan Services [Member]
Goodwill [Roll Forward]
Acquisition balance as of beginning-of-year	20	20
Impairment
Balance as of end-of-year	20	20
Life Insurance [Member]
Goodwill [Roll Forward]
Acquisition balance as of beginning-of-year	1,539	2,188
Cumulative impairment as of beginning-of-year	(649)	(649)
Impairment
Balance as of end-of-year	1,539	1,539
Group Protection [Member]
Goodwill [Roll Forward]
Acquisition balance as of beginning-of-year	274	274
Impairment
Balance as of end-of-year	274	274
Other Operations [Member]
Goodwill [Roll Forward]
Acquisition balance as of beginning-of-year		341
Cumulative impairment as of beginning-of-year	(341)	(341)
Impairment