INVESTMENT SECURITIES (Contractual Maturity of HTM Debt Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Amortized Cost
Due within one year	$ 0
Due after 1 year but within 5 years	17,207
Due after 5 years but within 10 years	6,135
Due after 10 years	5,206,220
Amortized Cost	5,229,562	$ 3,938,797
Fair Value
Due within one year	0
Due after 1 year but within 5 years	17,307
Due after 5 years but within 10 years	6,388
Due after 10 years	5,391,025
Investments in debt securities HTM	$ 5,414,720	$ 3,957,227

Amount of investment in debt security measured at amortized cost (held-to-maturity).

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