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)
September 30, 2023:
Assets
Derivative financial instruments	$	212,345	$	—	$	212,345	$	—
Loans held for sale		27,443		—		27,443		—
Trading securities		114,154		—		114,154		—
Securities available for sale:
U.S. Treasuries		172,259		—		172,259		—
U.S. Government agencies		216,754		—		216,754		—
Residential mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,488,706		—		1,488,706		—
Residential collateralized mortgage-obligations issued by U.S. government
agencies or sponsored enterprises		519,427		—		519,427		—
Commercial mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		949,532		—		949,532		—
State and municipal obligations		873,007		—		873,007		—
Small Business Administration loan-backed securities		377,470		—		377,470		—
Corporate securities		26,463		—		26,463		—
Total securities available for sale		4,623,618		—		4,623,618		—
Mortgage servicing rights		89,476		—		—		89,476
SBA servicing asset		5,654		—		—		5,654
	$	5,072,690	$	—	$	4,977,560	$	95,130
Liabilities
Derivative financial instruments	$	1,251,878	$	—	$	1,251,878	$	—

December 31, 2022:
Assets
Derivative financial instruments	$	211,016	$	—	$	211,016	$	—
Loans held for sale		28,968		—		28,968		—
Trading securities		31,263		—		31,263		—
Securities available for sale:
U.S. Treasuries		265,638		—		265,638		—
U.S. Government agencies		219,088		—		219,088		—
Residential mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,698,353		—		1,698,353		—
Residential collateralized mortgage-obligations issued by U.S. government
agencies or sponsored enterprises		601,045		—		601,045		—
Commercial mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,000,398		—		1,000,398		—
State and municipal obligations		1,064,852		—		1,064,852		—
Small Business Administration loan-backed securities		444,810		—		444,810		—
Corporate securities		32,638		—		32,638		—
Total securities available for sale		5,326,822		—		5,326,822		—
Mortgage servicing rights		86,610		—		—		86,610
SBA servicing asset		6,068		—		—		6,068
	$	5,690,747	$	—	$	5,598,069	$	92,678
Liabilities
Derivative financial instruments	$	1,034,143	$	—	$	1,034,143	$	—

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)
September 30, 2023:
OREO	$	434	$	—	$	—	$	434
Bank properties held for sale		15,251		—		—		15,251
Individually evaluated loans		76,890		—		—		76,890
December 31, 2022:
OREO	$	1,023	$	—	$	—	$	1,023
Bank properties held for sale		17,754		—		—		17,754
Individually evaluated loans		20,802		—		—		20,802

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
September 30, 2023
Financial assets:
Cash and cash equivalents	$	1,329,137	$	1,329,137	$	1,329,137	$	—	$	—
Trading securities		114,154		114,154		—		114,154		—
Investment securities		7,344,483		6,823,170		187,152		6,636,018		—
Loans held for sale		27,443		27,443		—		27,443		—
Loans, net of allowance for credit losses		31,568,716		29,773,087		—		—		29,773,087
Accrued interest receivable		151,259		151,259		—		26,561		124,698
Mortgage servicing rights		89,476		89,476		—		—		89,476
SBA servicing asset		5,654		5,654		—		—		5,654
Interest rate swap – non-designated hedge		211,109		211,109		—		211,109		—
Other derivative financial instruments (mortgage banking related)		1,236		1,236		—		1,236		—
Financial liabilities:
Deposits
Noninterest-bearing		11,158,431		11,158,431		—		11,158,431		—
Interest-bearing other than time deposits		21,322,840		21,322,840		—		21,322,840		—
Time deposits		4,453,927		4,391,875		—		4,391,875		—
Federal funds purchased and securities sold under agreements to repurchase		513,304		513,304		—		513,304		—
Corporate and subordinated debentures		391,997		376,373		—		376,373		—
Other borrowings		—		—		—		—		—
Accrued interest payable		45,163		45,163		—		45,163		—
Interest rate swap – non-designated hedge		1,251,059		1,251,059		—		1,251,059		—
Other derivative financial instruments (mortgage banking related)		819		819		—		819		—
Off balance sheet financial instruments:
Commitments to extend credit		—		(604,493)		—		(604,493)		—
December 31, 2022
Financial assets:
Cash and cash equivalents	$	1,312,563	$	1,312,563	$	1,312,563	$	—	$	—
Trading securities		31,263		31,263		—		31,263		—
Investment securities		8,189,780		7,756,707		179,717		7,576,990		—
Loans held for sale		28,968		28,968		—		28,968		—
Loans, net of allowance for credit losses		29,821,418		29,329,499		—		—		29,329,499
Accrued interest receivable		134,594		134,594		—		28,449		106,145
Mortgage servicing rights		86,610		86,610		—		—		86,610
SBA servicing asset		6,068		—		—		—		6,068
Interest rate swap – non-designated hedge		210,216		210,216		—		210,216		—
Other derivative financial instruments (mortgage banking related)		800		800		—		800		—
Financial liabilities:
Deposits
Noninterest-bearing		13,168,656		13,168,656		—		13,168,656		—
Interest-bearing other than time deposits		20,761,981		20,761,981		—		20,761,981		—
Time deposits		2,419,986		2,333,764		—		2,333,764		—
Federal funds purchased and securities sold under agreements to repurchase		556,417		556,417		—		556,417		—
Corporate and subordinated debentures		392,275		377,360		—		377,360		—
Accrued interest payable		6,218		6,218		—		3,345		—
Interest rate swap – non-designated hedge		1,033,980		1,033,980		—		1,033,980		—
Other derivative financial instruments (mortgage banking related)		163		163		—		163		—
Off balance sheet financial instruments:
Commitments to extend credit		—		(184,801)		—		(184,801)		—

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, 2023	$	86,610
Servicing assets that resulted from transfers of financial assets		6,752
Changes in fair value due to valuation inputs or assumptions		2,450
Changes in fair value due to decay		(6,336)
Fair value, September 30, 2023	$	89,476

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, 2023	$	6,068
Servicing assets that resulted from transfers of financial assets		1,103
Changes in fair value due to decay		(1,951)
Changes in fair value due to valuation inputs or assumptions		434
Fair value, September 30, 2023	$	5,654