FAIR VALUE MEASUREMENTS - Carrying Amounts and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Assets:
Cash and cash equivalents	$ 1,317,129	$ 656,494
Securities AFS, net	211,324	226,158
Securities HTM	847,036	862,544
Loans, net	10,638,708	10,692,462
Investment in FHLB stock	58,716	25,358
Investment in equity securities	9,758	9,767
Liabilities:
Deposits	10,051,706	10,362,612
Borrowings	2,294,600	1,369,936
Assets Fair Value:
Cash and cash equivalents	1,317,129	656,494
Securities AFS, net	211,324	226,158
Securities HTM	766,907	773,061
Loans, net	10,302,070	10,354,052
Investment in FHLB stock	58,716	25,358
Investment in equity securities	9,758	9,767
Liabilities Fair Value:
Deposits	10,034,478	10,349,272
Borrowings	2,173,121	1,329,722
Fair Value Measurement Level 1
Assets Fair Value:
Cash and cash equivalents	1,317,129	656,494
Securities AFS, net	1,244	1,228
Liabilities Fair Value:
Deposits	7,625,291	8,483,770
Borrowings	2,020,000	1,176,601
Fair Value Measurement Level 2
Assets:
Investment in FHLB stock	58,716	25,358
Assets Fair Value:
Securities AFS, net	203,250	216,949
Securities HTM	766,907	773,061
Investment in FHLB stock	58,716	25,358
Liabilities Fair Value:
Deposits	2,409,187	1,865,502
Fair Value Measurement Level 3
Assets:
Investment in equity securities	9,758	9,767
Assets Fair Value:
Securities AFS, net	6,830	7,981
Loans, net	10,302,070	10,354,052
Investment in equity securities	9,758	9,767
Liabilities Fair Value:
Borrowings	$ 153,121	$ 153,121