INVESTMENT SECURITIES - Contractual Maturities of Debt Securities Available for Sale (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Amortized Cost
Due within one year	$ 461
Due after one year through five years	2,061
Due after five years through ten years	2,958
Due after ten years	1,498
Mortgage and asset-backed securities	6,615
Amortized Cost	13,593	$ 12,437
Fair Value
Due within one year	465
Due after one year through five years	2,134
Due after five years through ten years	3,035
Due after ten years	1,529
Mortgage and asset-backed securities	6,697
Fair Value	$ 13,860	$ 12,951

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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