Supplemental Cash Flow Information - Activities resulting from management of proceeds (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net change in proceeds managed
Net change in short-term investments	$ (63)	$ (183)
Operating cash flow (used)	(63)	(183)
Net change in cash	3	1
Net change in proceeds managed	(60)	(182)
Change in Liabilities for Collateral [Roll Forward]
Liabilities for collateral, beginning of period	(1,444)	(914)
Liabilities for collateral, end of period	(1,504)	(1,096)
Operating cash flow provided	$ 60	$ 182