Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING ACTIVITIES
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 52,004	$ 32,884
INVESTING ACTIVITIES
Net decrease (increase) in loans held for investment	100,799	(131,110)
Available-for-sale debt securities:
Proceeds from sales	0	222,668
Proceeds from maturities, prepayments and calls	239,259	157,954
Purchases of securities	(1,068,526)	(197,153)
Held-to-maturity debt securities:
Proceeds from maturities, prepayments and calls	27,147	48,093
Purchases of securities	(110,298)	(11,734)
Equity securities:
Proceeds from sales		50
Proceeds from bank owned life insurance		10
Purchases of premises and equipment – net	(2,362)	(2,925)
Sale of portfolio loans		28,262
Net cash (used in) provided by investing activities	(813,981)	114,115
FINANCING ACTIVITIES
Increase in deposits	858,853	42,892
Proceeds from Federal Home Loan Bank borrowings		475,000
Repayment of Federal Home Loan Bank borrowings	(115,053)	(305,070)
(Decrease) increase in other short-term borrowings	(104,732)	59,104
Principal repayments of finance lease obligations	(109)	(104)
Decrease in federal funds purchased		(7,500)
Repayment of junior subordinated debt		(6,702)
Dividends paid to common shareholders	(21,419)	(21,016)
Dividends paid to preferred shareholders	(2,531)
Treasury shares sold (purchased) - net	569	(24,527)
Net cash provided by financing activities	615,578	212,077
Net (decrease) increase in cash, cash equivalents and restricted cash	(146,399)	359,076
Cash, cash equivalents and restricted cash at beginning of the period	905,447	234,796
Cash, cash equivalents and restricted cash at end of the period	759,048	593,872
SUPPLEMENTAL DISCLOSURES
Interest paid on deposits and other borrowings	$ 10,719	26,074
Transfers of loans to other real estate owned		28
Transfers of portfolio loans to loans held for sale		$ 37,195