Fair Values (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Investment securities:
Equity securities	$ 50	$ 81
Debt securities	21,220
Fair Value, Recurring
Investment securities:
Equity securities	50	81
Debt securities	21,220	21,550
Derivatives, gross	629	629
Total Assets	21,899	22,260
Liabilities
Derivatives, gross	212	702
Total Liabilities	212	702
Level 1 \| Fair Value, Recurring
Investment securities:
Equity securities	49	80
Debt securities	0	0
Derivatives, gross	0	0
Total Assets	49	80
Liabilities
Derivatives, gross	0	0
Total Liabilities	0	0
Level 2 \| Fair Value, Recurring
Investment securities:
Equity securities	1	1
Debt securities	21,200	21,550
Derivatives, gross	629	629
Total Assets	21,830	22,180
Liabilities
Derivatives, gross	212	702
Total Liabilities	212	702
Level 3 \| Fair Value, Recurring
Investment securities:
Equity securities	0	0
Debt securities	20	0
Derivatives, gross	0	0
Total Assets	20	0
Liabilities
Derivatives, gross	0	0
Total Liabilities	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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