FAIR VALUE - Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets:
Investment securities available for sale	$ 5,599,520	$ 6,453,761
Held To Maturity Securities Amortized	437,537	178,133
Less: allowance for credit losses on held to maturity securities	(8,286)	(8,571)
Investment securities held to maturity, net of ACL	429,251	169,562
Less: ACL for loans and finance leases	(260,464)	(269,030)	$ (385,887)	$ (155,139)
Loans held for investment, net of ACL	11,292,361	10,791,628
Mortgage servicing rights	29,037	30,986	$ 33,071	$ 26,762
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]
Other borrowings	183,762	183,762
Carrying Reported Amount Fair Value Disclosure [Member]
Assets:
Cash and due from banks and money market investments	480,505	2,543,058
Investment securities available for sale	5,599,520	6,453,761
Held To Maturity Securities Amortized	437,537	178,133
Less: allowance for credit losses on held to maturity securities	(8,286)	(8,571)
Investment securities held to maturity, net of ACL	429,251	169,562
Equity Securities	50,428	26,791
Other investment securities	4,861	5,378
Loans held for sale	12,306	35,155
Total gross loans held for investment portfolio	11,552,825	11,060,658
Less: ACL for loans and finance leases	(260,464)	(269,030)
Loans held for investment, net of ACL	11,292,361	10,791,628
Mortgage servicing rights	29,037	30,986
Derivative Assets	633	1,505
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]
Deposits	16,143,467	17,784,894
Securities sold under agreements to repurchase	75,133	300,000
Advances from FHLB	675,000	200,000
Other borrowings	183,762	183,762
Derivative Liabilities	476	1,178
Federal Home Loan Bank Stock	42,900	21,500
Estimate Of Fair Value Fair Value Disclosure [Member]
Assets:
Cash and due from banks and money market investments	480,505	2,543,058
Investment securities available for sale	5,599,520	6,453,761
Investment securities held to maturity, net of ACL	427,115	167,147
Equity Securities	50,428	26,791
Other investment securities	4,861	5,378
Loans held for sale	12,306	36,147
Loans held for investment, net of ACL	11,106,809	10,900,400
Mortgage servicing rights	44,710	42,132
Derivative Assets	633	1,505
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]
Deposits	16,139,937	17,800,706
Securities sold under agreements to repurchase	75,230	322,105
Advances from FHLB	674,596	202,044
Other borrowings	187,246	177,689
Derivative Liabilities	476	1,178
Estimate Of Fair Value Fair Value Disclosure [Member] | Fair Value Inputs Level 1 [Member]
Assets:
Cash and due from banks and money market investments	480,505	2,543,058
Investment securities available for sale	138,875	148,486
Investment securities held to maturity, net of ACL	0	0
Equity Securities	0	0
Other investment securities	4,861	5,378
Loans held for sale	0	0
Loans held for investment, net of ACL	0	0
Mortgage servicing rights	0	0
Derivative Assets	0	0
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]
Deposits	0	0
Securities sold under agreements to repurchase	0	0
Advances from FHLB	0	0
Other borrowings	0	0
Derivative Liabilities	0	0
Estimate Of Fair Value Fair Value Disclosure [Member] | Fair Value Inputs Level 2 [Member]
Assets:
Cash and due from banks and money market investments	0	0
Investment securities available for sale	5,452,150	6,294,191
Investment securities held to maturity, net of ACL	260,106	0
Equity Securities	50,428	26,791
Other investment securities	0	0
Loans held for sale	12,306	36,147
Loans held for investment, net of ACL	0	0
Mortgage servicing rights	0	0
Derivative Assets	633	1,505
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]
Deposits	16,139,937	17,800,706
Securities sold under agreements to repurchase	75,230	322,105
Advances from FHLB	674,596	202,044
Other borrowings	0	0
Derivative Liabilities	476	1,178
Estimate Of Fair Value Fair Value Disclosure [Member] | Fair Value Inputs Level 3 [Member]
Assets:
Cash and due from banks and money market investments	0	0
Investment securities available for sale	8,495	11,084
Investment securities held to maturity, net of ACL	167,009	167,147
Equity Securities	0	0
Other investment securities	0	0
Loans held for sale	0	0
Loans held for investment, net of ACL	11,106,809	10,900,400
Mortgage servicing rights	44,710	42,132
Derivative Assets	0	0
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]
Deposits	0	0
Securities sold under agreements to repurchase	0	0
Advances from FHLB	0	0
Other borrowings	187,246	177,689
Derivative Liabilities	$ 0	$ 0