Schedule of recorded amount of assets and liabilities measured at fair value on a recurring basis


			Quoted Prices
			In Active		Significant
			Markets		Other		Significant
			for Identical		Observable		Unobservable
			Assets		Inputs		Inputs
(Dollars in thousands)	Fair Value		(Level 1)		(Level 2)		(Level 3)
March 31, 2024:
Assets
Derivative financial instruments	$	176,784	$	—	$	176,784	$	—
Loans held for sale		56,553		—		56,553		—
Trading securities		66,188		—		66,188		—
Securities available for sale:
U.S. Treasuries		24,587		—		24,587		—
U.S. Government agencies		223,805		—		223,805		—
Residential mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,492,423		—		1,492,423		—
Residential collateralized mortgage-obligations issued by U.S. government
agencies or sponsored enterprises		508,112		—		508,112		—
Commercial mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,012,217		—		1,012,217		—
State and municipal obligations		960,359		—		960,359		—
Small Business Administration loan-backed securities		350,043		—		350,043		—
Corporate securities		26,854		—		26,854		—
Total securities available for sale		4,598,400		—		4,598,400		—
Mortgage servicing rights		87,970		—		—		87,970
SBA servicing asset		6,367		—		—		6,367
	$	4,992,262	$	—	$	4,897,925	$	94,337
Liabilities
Derivative financial instruments	$	954,788	$	—	$	954,788	$	—

December 31, 2023:
Assets
Derivative financial instruments	$	172,939	$	—	$	172,939	$	—
Loans held for sale		50,888		—		50,888		—
Trading securities		31,321		—		31,321		—
Securities available for sale:
U.S. Treasuries		73,890		—		73,890		—
U.S. Government agencies		224,706		—		224,706		—
Residential mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,558,306		—		1,558,306		—
Residential collateralized mortgage-obligations issued by U.S. government
agencies or sponsored enterprises		527,422		—		527,422		—
Commercial mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,024,170		—		1,024,170		—
State and municipal obligations		977,461		—		977,461		—
Small Business Administration loan-backed securities		371,686		—		371,686		—
Corporate securities		26,747		—		26,747		—
Total securities available for sale		4,784,388		—		4,784,388		—
Mortgage servicing rights		85,164		—		—		85,164
SBA servicing asset		5,952		—		—		5,952
	$	5,130,652	$	—	$	5,039,536	$	91,116
Liabilities
Derivative financial instruments	$	804,486	$	—	$	804,486	$	—

Schedule of amounts of assets and liabilities measured at fair value on a nonrecurring basis


			Quoted Prices
			In Active		Significant
			Markets		Other		Significant
			for Identical		Observable		Unobservable
			Assets		Inputs		Inputs
(Dollars in thousands)	Fair Value		(Level 1)		(Level 2)		(Level 3)
March 31, 2024:
OREO	$	1,644	$	—	$	—	$	1,644
Bank properties held for sale		8,973		—		—		8,973
Individually evaluated loans		64,191		—		—		64,191
December 31, 2023:
OREO	$	837	$	—	$	—	$	837
Bank properties held for sale		12,401		—		—		12,401
Individually evaluated loans		73,518		—		—		73,518

Schedule of estimated fair value, and related carrying amount, of the Company's financial instruments


	Carrying		Fair
(Dollars in thousands)	Amount		Value		Level 1		Level 2		Level 3
March 31, 2024
Financial assets:
Cash and cash equivalents	$	1,209,457	$	1,209,457	$	1,209,457	$	—	$	—
Trading securities		66,188		66,188		—		66,188		—
Investment securities		7,232,274		6,802,252		187,285		6,614,967		—
Loans held for sale		56,553		56,553		—		56,553		—
Loans, net of allowance for credit losses		32,197,656		31,124,727		—		—		31,124,727
Accrued interest receivable		160,519		160,519		—		25,665		134,854
Mortgage servicing rights		87,970		87,970		—		—		87,970
SBA servicing asset		6,367		6,367		—		—		6,367
Interest rate swap – non-designated hedge		174,373		174,373		—		174,373		—
Other derivative financial instruments (mortgage banking related)		2,411		2,411		—		2,411		—
Financial liabilities:
Deposits
Noninterest-bearing		10,546,410		10,546,410		—		10,546,410		—
Interest-bearing other than time deposits		22,351,423		22,351,423		—		22,351,423		—
Time deposits		4,280,601		4,238,055		—		4,238,055		—
Federal funds purchased and securities sold under agreements to repurchase		554,691		554,691		—		554,691		—
Corporate and subordinated debentures		391,812		385,574		—		385,574		—
Other borrowings		—		—		—		—		—
Accrued interest payable		44,873		44,873		—		44,873		—
Interest rate swap – non-designated hedge		954,297		954,297		—		954,297		—
Other derivative financial instruments (mortgage banking related)		491		491		—		491		—
December 31, 2023
Financial assets:
Cash and cash equivalents	$	998,877	$	998,877	$	998,877	$	—	$	—
Trading securities		31,321		31,321		—		31,321		—
Investment securities		7,463,871		7,061,167		192,043		6,869,124		—
Loans held for sale		50,888		50,888		—		50,888		—
Loans, net of allowance for credit losses		31,931,916		30,709,513		—		—		30,709,513
Accrued interest receivable		154,400		154,400		—		26,706		127,694
Mortgage servicing rights		85,164		85,164		—		—		85,164
SBA servicing asset		5,952		5,952		—		—		5,952
Interest rate swap – non-designated hedge		169,180		169,180		—		169,180		—
Other derivative financial instruments (mortgage banking related)		3,759		3,759		—		3,759		—
Financial liabilities:
Deposits
Noninterest-bearing		10,649,274		10,649,274		—		10,649,274		—
Interest-bearing other than time deposits		22,149,682		22,149,682		—		22,149,682		—
Time deposits		4,249,953		4,208,498		—		4,208,498		—
Federal funds purchased and securities sold under agreements to repurchase		489,185		489,185		—		489,185		—
Corporate and subordinated debentures		391,904		388,909		—		388,909		—
Other borrowings		100,000		100,000		—		100,000		—
Accrued interest payable		56,808		56,808		—		56,808		—
Interest rate swap – non-designated hedge		803,539		803,539		—		803,539		—
Other derivative financial instruments (mortgage banking related)		947		947		—		947		—

Schedule of reconciliation of the beginning and ending balances of Level 3 assets, comprised of Mortgage Servicing Rights, SBA servicing asset and liabilities recorded at fair value on a recurring basis


(Dollars in thousands)	MSRs
Fair value, January 1, 2024	$	85,164
Servicing assets that resulted from transfers of financial assets		1,864
Changes in fair value due to valuation inputs or assumptions		2,384
Changes in fair value due to decay		(1,442)
Fair value, March 31, 2024	$	87,970

Schedule of reconciliation of the beginning and ending balances of Level 3 assets, comprised of Mortgage Servicing Rights, SBA servicing asset and liabilities recorded at fair value on a recurring basis


(Dollars in thousands)	SBA Servicing Asset
Fair value, January 1, 2024	$	5,952
Servicing assets that resulted from transfers of financial assets		581
Changes in fair value due to decay		(364)
Changes in fair value due to valuation inputs or assumptions		198
Fair value, March 31, 2024	$	6,367