Derivative Instruments - Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative assets
Gross amount recognized	$ 2,771	$ 2,888
Financial instruments	(61)	(67)
Collateral (received)/pledged	(2,564)	(2,743)
Net amount	146	78
Off-balance sheet securities collateral	(41)	(145)
Net amount after securities collateral	105	(67)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative liabilities
Gross amount recognized	(147)	(97)
Financial instruments	61	67
Collateral (received)/pledged	77	31
Net amount	(9)	1
Net amount after securities collateral	$ 9	$ 1

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