Offsetting Assets and Liabilities (Assets) (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Derivatives:
Gross amounts of recognized assets	[1]	$ 5,711	$ 4,283
OTC derivatives [Member]
Derivatives:
Gross amounts of recognized assets		5,417	4,181
Gross Amounts Not Offset in the Consolidated Balance Sheets
Financial instruments	[2]	(3,146)	(2,886)
Cash collateral		(2,173)	(1,214)
Securities collateral		(58)	(73)
Net amount		40	8
OTC cleared derivatives [Member]
Derivatives:
Gross amounts of recognized assets		30	21
Gross Amounts Not Offset in the Consolidated Balance Sheets
Financial instruments	[2]	(30)	(21)
Net amount		0	0
Exchange-traded derivatives [Member]
Derivatives:
Gross amounts of recognized assets		264	81
Gross Amounts Not Offset in the Consolidated Balance Sheets
Financial instruments	[2]	(102)	(5)
Net amount		162	76
Total derivatives [Member]
Derivatives:
Gross amounts of recognized assets		5,711	4,283
Gross Amounts Not Offset in the Consolidated Balance Sheets
Financial instruments	[2]	(3,278)	(2,912)
Cash collateral		(2,173)	(1,214)
Securities collateral		(58)	(73)
Net amount		$ 202	$ 84

[1] The fair value of freestanding derivative assets is included in Other assets on the Consolidated Balance Sheets.

[2] Represents the amount of assets that could be offset by liabilities with the same counterparty under master netting or similar arrangements that management elects not to offset on the Consolidated Balance Sheets.