Fair Value Measurements (Details 5) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financial assets:
Cash and cash equivalents		$ 1,220	$ 1,343	$ 1,639	$ 1,705
Mortgage loans		1,067	1,117
Policy loans		201	228
Financial liabilities:
Long-term debt		1,020	1,061
Level 1 [Member]
Financial assets:
Cash and cash equivalents		1,220	1,343
Mortgage loans		0	0
Policy loans		0	0
Total financial assets not accounted for at fair value		1,220	1,343
Financial liabilities:
Annuity benefits accumulated	[1]	0	0
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	[1]	0	0
Long-term debt		1,105	1,106
Total financial liabilities not accounted for at fair value		1,105	1,106
Level 3 [Member]
Financial assets:
Cash and cash equivalents		0	0
Mortgage loans		1,074	1,124
Policy loans		201	228
Total financial assets not accounted for at fair value		1,275	1,352
Financial liabilities:
Annuity benefits accumulated	[1]	25,488	23,187
Long-term debt		15	74
Total financial liabilities not accounted for at fair value		25,503	23,261
Carrying Value [Member]
Financial assets:
Cash and cash equivalents		1,220	1,343
Mortgage loans		1,067	1,117
Policy loans		201	228
Total financial assets not accounted for at fair value		2,488	2,688
Financial liabilities:
Annuity benefits accumulated	[1]	26,422	23,561
Long-term debt		1,022	1,061
Total financial liabilities not accounted for at fair value		27,444	24,622
Fair Value [Member]
Financial assets:
Cash and cash equivalents		1,220	1,343
Mortgage loans		1,074	1,124
Policy loans		201	228
Total financial assets not accounted for at fair value		2,495	2,695
Financial liabilities:
Annuity benefits accumulated	[1]	25,488	23,187
Long-term debt		1,120	1,180
Total financial liabilities not accounted for at fair value		$ 26,608	$ 24,367

[1] Excludes $200 million and $203 million of life contingent annuities in the payout phase at December 31, 2015 and 2014, respectively.