Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Non-cash modifications of certain mortgage loans, fixed income securities, limited partnerships and other investments, as well as mergers completed with equity securities	$ 117	$ 96	$ 102
Liabilities assumed	34
Notes due to related parties	465	275
Liabilities for collateral received reported in other liabilities and accrued expenses	545	539	508
Obligations to return cash collateral for over-the-counter ("OTC") derivatives reported in other liabilities and accrued expenses or other investments	5	11	2
Net change in proceeds managed
Net change in fixed income securities	(277)	0	0
Net change in short-term investments	277	(41)	(182)
Operating cash flow used	0	(41)	(182)
Net change in cash	0	1	0
Net change in proceeds managed	0	(40)	(182)
Net change in liabilities
Liabilities for collateral, beginning of year	(550)	(510)	(328)
Liabilities for collateral, end of year	(550)	(550)	(510)
Operating cash flow provided	0	40	$ 182
Limited Partnership
Debt Instrument [Line Items]
Liabilities assumed	56	$ 44
Debt and Equity Securities
Debt Instrument [Line Items]
Payments of dividends	86
Kennett | 4.14% Surplus Note, due 2036 | ALIC Re
Debt Instrument [Line Items]
Notes due to related parties	$ 50