Policyholder Account Balances, Future Policy Benefits and Claims and Separate Account Liabilities (Balances by product) (Details) - USD ($) $ in Millions		Jun. 30, 2018	Dec. 31, 2017
Policyholder account balances		$ 20,062	$ 20,251
Future policy benefits		8,291	8,750
Policy claims and other policyholders' funds		902	903
Policyholder account balances, future policy benefits and claims		29,255	29,904
Fixed annuities [Member]
Policyholder account balances	[1]	9,624	9,934
Variable annuity fixed sub-accounts [Member]
Policyholder account balances		5,130	5,166
VUL/UL insurance [Member]
Policyholder account balances		3,047	3,047
IUL [Member]
Policyholder account balances		1,563	1,384
Other life insurance [Member]
Policyholder account balances		698	720
Variable annuity GMWB [Member]
Future policy benefits		128	463
Variable annuity GMAB [Member]
Future policy benefits	[2]	(75)	(80)
Other annuity liabilities [Member]
Future policy benefits		26	78
Fixed annuities life contingent liabilities [Member]
Future policy benefits		1,470	1,484
Life and disability income insurance [Member]
Future policy benefits		1,216	1,221
Long term care insurance [Member]
Future policy benefits		4,861	4,896
VUL/UL and other life insurance additional liabilities [Member]
Future policy benefits		$ 665	$ 688

[1] Includes fixed deferred annuities, non-life contingent fixed payout annuities and indexed annuity host contracts.

[2] Includes the fair value of GMAB embedded derivatives that was a net asset as of both June 30, 2018 and December 31, 2017 reported as a contra liability.