INVESTMENT SECURITIES - Contractual Maturities of Debt Securities Available for Sale (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Amortized Cost
Due within one year	$ 839
Due after one year through five years	2,277
Due after five years through ten years	1,730
Due after ten years	501
Mortgage and asset-backed securities	5,214
Amortized Cost	10,561	$ 10,641
Fair Value
Due within one year	840
Due after one year through five years	2,312
Due after five years through ten years	1,789
Due after ten years	524
Mortgage and asset-backed securities	5,339
Fair Value	$ 10,804	$ 10,437

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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