Investments (Net Investment Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net Investment Income [Line Items]
Less: Investment expenses	$ 308	$ 298	$ 923	$ 873
Subtotal	3,959	5,410	14,367	15,704
Securities Investment
Net Investment Income [Line Items]
Subtotal	4,964	5,321	15,355	15,793
Subtotal	4,656	5,023	14,432	14,920
Fixed maturity securities
Net Investment Income [Line Items]
Subtotal	3,525	3,695	10,738	11,106
Equity securities
Net Investment Income [Line Items]
Subtotal	36	31	102	98
Actively traded securities and FVO general account securities
Net Investment Income [Line Items]
Subtotal	(35)	14	4	95
Changes in estimated fair value included in net investment income	(39)	(18)	(45)	7
Mortgage loans
Net Investment Income [Line Items]
Subtotal	786	775	2,317	2,192
Policy loans
Net Investment Income [Line Items]
Subtotal	147	158	450	473
Real estate and real estate joint ventures
Net Investment Income [Line Items]
Subtotal	233	245	767	724
Other limited partnership interests
Net Investment Income [Line Items]
Subtotal	216	299	681	834
Cash, cash equivalents and short-term investments
Net Investment Income [Line Items]
Subtotal	29	42	101	130
Operating joint ventures
Net Investment Income [Line Items]
Subtotal	(1)	2	15	5
Other
Net Investment Income [Line Items]
Subtotal	28	60	180	136
Consolidated Securitization Entities And Fair Value Option Contractholder-Directed Unit-Linked
Net Investment Income [Line Items]
Subtotal	(697)	387	(65)	784
FVO contractholder-directed unit-linked investments
Net Investment Income [Line Items]
Subtotal	(701)	379	(79)	739
Changes in estimated fair value included in net investment income	(833)	248	(600)	329
Commercial mortgage loans | Consolidated Securitization Entities
Net Investment Income [Line Items]
Subtotal	4	8	13	44
Securities | Consolidated Securitization Entities
Net Investment Income [Line Items]
Subtotal	$ 0	$ 0	$ 1	$ 1