Fair Value Measurements (Details 4) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013	Dec. 31, 2012
Financial assets:
Cash and cash equivalents	$ 1,876		$ 1,639		$ 1,529	$ 1,705
Mortgage loans	888		781
Policy loans	235		238
Financial liabilities:
Long-term debt	913		913
Level 1 [Member]
Financial assets:
Cash and cash equivalents	1,876		1,639
Mortgage loans	0		0
Policy loans	0		0
Total financial assets not accounted for at fair value	1,876		1,639
Financial liabilities:
Annuity benefits accumulated	0	[1]	0	[1]
Long-term debt	0		0
Total financial liabilities not accounted for at fair value	0		0
Level 2 [Member]
Financial assets:
Cash and cash equivalents	0		0
Mortgage loans	0		0
Policy loans	0		0
Total financial assets not accounted for at fair value	0		0
Financial liabilities:
Annuity benefits accumulated	0	[1]	0	[1]
Long-term debt	942		909
Total financial liabilities not accounted for at fair value	942		909
Level 3 [Member]
Financial assets:
Cash and cash equivalents	0		0
Mortgage loans	886		779
Policy loans	235		238
Total financial assets not accounted for at fair value	1,121		1,017
Financial liabilities:
Annuity benefits accumulated	20,860	[1]	19,959	[1]
Long-term debt	76		76
Total financial liabilities not accounted for at fair value	20,936		20,035
Carrying Value [Member]
Financial assets:
Cash and cash equivalents	1,876		1,639
Mortgage loans	888		781
Policy loans	235		238
Total financial assets not accounted for at fair value	2,999		2,658
Financial liabilities:
Annuity benefits accumulated	21,542	[1]	20,741	[1]
Long-term debt	913		913
Total financial liabilities not accounted for at fair value	22,455		21,654
Fair Value [Member]
Financial assets:
Cash and cash equivalents	1,876		1,639
Mortgage loans	886		779
Policy loans	235		238
Total financial assets not accounted for at fair value	2,997		2,656
Financial liabilities:
Annuity benefits accumulated	20,860	[1]	19,959	[1]
Long-term debt	1,018		985
Total financial liabilities not accounted for at fair value	$ 21,878		$ 20,944

[1] Excludes life contingent annuities in the payout phase.