Supplemental Cash Flow Information - Net change (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net change in proceeds managed
Net change in fixed income securities	$ 80	$ 234	$ 259
Net change in short-term investments	(451)	(568)	(255)
Operating cash flow (used) provided	(371)	(334)	4
Net change in cash	0	0	1
Net change in proceeds managed	(371)	(334)	5
Net change in liabilities
Liabilities for collateral, beginning of year	(1,458)	(1,124)	(1,129)
Liabilities for collateral, end of year	(1,829)	(1,458)	(1,124)
Operating cash flow provided (used)	$ 371	$ 334	$ (5)