Investments (Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Total Assets	$ 6,224	$ 6,323
Total Liabilities	2,205	2,169
CSEs (assets (primarily loans) and liabilities (primarily debt))
Variable Interest Entity [Line Items]
Total Assets	219	297
Total Liabilities	74	155
MRSC collateral financing arrangement
Variable Interest Entity [Line Items]
Total Assets	3,399	3,471
Total Liabilities	0	0
Operating joint venture
Variable Interest Entity [Line Items]
Total Assets	2,445	2,405
Total Liabilities	2,045	1,999
Other limited partnership interests
Variable Interest Entity [Line Items]
Total Assets	29	37
Total Liabilities	0	0
Real estate joint ventures
Variable Interest Entity [Line Items]
Total Assets	0	9
Total Liabilities	0	15
Mortgage loans
Variable Interest Entity [Line Items]
Total Assets	86	0
Total Liabilities	86	0
Other invested assets
Variable Interest Entity [Line Items]
Total Assets	46	59
Total Liabilities	0	0
FVO and trading securities
Variable Interest Entity [Line Items]
Total Assets	0	45
Total Liabilities	$ 0	$ 0