Investments (Amortized Cost and Fair Value of Fixed Maturities by Contractual Maturities) (Details) - USD ($) $ in Millions		Jun. 30, 2016	Dec. 31, 2015
Available for Sale Amortized Cost
Due in one year or less		$ 12,437
Due after one year through five years		47,952
Due after five years through ten years		58,735
Due after ten years		141,353
Total		286,066	$ 265,416
Available for Sale Securities Fair Value
Due in one year or less		13,082
Due after one year through five years		52,497
Due after five years through ten years		64,754
Due after ten years		175,330
Fair Value	[1]	332,270	290,323
Held to Maturity Securities Amortized Cost
Due in one year or less		8
Due after one year through five years		80
Due after five years through ten years		702
Due after ten years		950
Fair Value	[1]	2,485	2,308
Held to Maturity Securities Fair Value
Due in one year or less		8
Due after one year through five years		85
Due after five years through ten years		784
Due after ten years		1,343
Total		3,026	2,624
Fixed maturities, available-for-sale
Available for Sale Amortized Cost
Total		286,066	265,416
Available for Sale Securities Fair Value
Fair Value		332,270	290,323
Held to Maturity Securities Amortized Cost
Fair Value		2,485	2,308
Held to Maturity Securities Fair Value
Total		3,026	2,624
Prudential Netting Agreement
Held to Maturity Securities Amortized Cost
Fair Value		3,990	3,850
Held to Maturity Securities Fair Value
Total		3,990	4,081
Prudential Netting Agreement | Fixed maturities, available-for-sale
Available for Sale Amortized Cost
Total		1,127	1,050
Available for Sale Securities Fair Value
Fair Value		1,127	1,039
Commercial mortgage-backed securities
Available for Sale Amortized Cost
Debt Maturities, without single maturity date		10,995
Available for Sale Securities Fair Value
Debt Maturities, without Single Maturity Date		11,643
Held to Maturity Securities Amortized Cost
Debt Maturities, without Single Maturity Date		11
Held to Maturity Securities Fair Value
Debt Maturities, without Single Maturity Date		11
Residential mortgage-backed securities
Available for Sale Amortized Cost
Debt Maturities, without single maturity date		4,432
Available for Sale Securities Fair Value
Debt Maturities, without Single Maturity Date		4,777
Held to Maturity Securities Amortized Cost
Debt Maturities, without Single Maturity Date		734
Held to Maturity Securities Fair Value
Debt Maturities, without Single Maturity Date		795
Asset-backed securities
Available for Sale Amortized Cost
Debt Maturities, without single maturity date		10,162
Available for Sale Securities Fair Value
Debt Maturities, without Single Maturity Date		10,187
Held to Maturity Securities Amortized Cost
Debt Maturities, without Single Maturity Date		0
Held to Maturity Securities Fair Value
Debt Maturities, without Single Maturity Date		0
Asset-backed securities | Fixed maturities, available-for-sale
Available for Sale Amortized Cost
Total		10,162	10,121
Available for Sale Securities Fair Value
Fair Value		$ 10,187	$ 10,226

[1] See Note 5 for details of balances associated with variable interest entities.