Fair Value (Tables)

3 Months Ended

Mar. 31, 2025

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, 2025:
Assets
Derivative financial instruments	$	177,262	$	—	$	177,262	$	—
Mortgage loans held for sale		86,772		—		86,772		—
Trading securities		107,401		—		107,401		—
Securities available for sale:
U.S. Treasuries		18,293		—		18,293		—
Residential mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,447,116		—		1,447,116		—
Residential collateralized mortgage-obligations issued by U.S. government
agencies or sponsored enterprises		2,347,134		—		2,347,134		—
Commercial mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		560,634		—		560,634		—
State and municipal obligations		910,649		—		910,649		—
Small Business Administration loan-backed securities		542,553		—		542,553		—
Corporate securities		26,990		—		26,990		—
Total securities available for sale		5,853,369		—		5,853,369		—
Mortgage servicing rights		87,742		—		—		87,742
SBA servicing asset		6,209		—		—		6,209
	$	6,318,755	$	—	$	6,224,804	$	93,951
Liabilities
Derivative financial instruments	$	698,933	$	—	$	698,933	$	—
December 31, 2024:
Assets
Derivative financial instruments	$	161,490	$	—	$	161,490	$	—
Mortgage loans held for sale		98,115		—		98,115		—
Trading securities		102,932		—		102,932		—
Securities available for sale:
U.S. Treasuries		10,656		—		10,656		—
U.S. Government agencies		150,418		—		150,418		—
Residential mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,377,525		—		1,377,525		—
Residential collateralized mortgage-obligations issued by U.S. government
agencies or sponsored enterprises		459,095		—		459,095		—
Commercial mortgage-backed securities issued by U.S. government
agencies or sponsored enterprises		1,040,555		—		1,040,555		—
State and municipal obligations		945,723		—		945,723		—
Small Business Administration loan-backed securities		310,112		—		310,112		—
Corporate securities		26,509		—		26,509		—
Total securities available for sale		4,320,593		—		4,320,593		—
Mortgage servicing rights		89,795		—		—		89,795
SBA servicing asset		6,028		—		—		6,028
	$	4,778,953	$	—	$	4,683,130	$	95,823
Liabilities
Derivative financial instruments	$	879,855	$	—	$	879,855	$	—

Schedule of mortgage loans held for sale

	March 31,		December 31,
(Dollars in thousands)	2025		2024
Fair value	$	86,772	$	98,115
Unpaid principal balance		83,826		95,612
Fair value less aggregated unpaid principal balance	$	2,946	$	2,503

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, 2025:
OREO	$	7,469	$	—	$	—	$	7,469
Bank properties held for sale		74,881		—		—		74,881
Individually evaluated loans		534,207		—		—		534,207
December 31, 2024:
OREO	$	2,154	$	—	$	—	$	2,154
Bank properties held for sale		3,268		—		—		3,268
Individually evaluated loans		71,112		—		—		71,112

Schedule of quantitative information about level 3 fair value measurements

			Weighted Average Discount
			March 31,		December 31,
	Valuation Technique	Unobservable Input	2025		2024
Nonrecurring measurements:
Individually evaluated loans	Discounted appraisals and discounted cash flows	Collateral discounts	13	%	28	%
OREO and Bank properties held for sale	Discounted appraisals	Collateral discounts and estimated costs to sell	5	%	10	%

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, 2025
Financial assets:
Cash and cash equivalents	$	3,299,690	$	3,299,690	$	3,299,690	$	—	$	—
Trading securities		107,401		107,401		—		107,401		—
Investment securities		8,395,044		8,019,537		280,119		7,673,842		65,576
Loans held for sale		357,918		357,918		—		357,918		—
Loans, net of allowance for credit losses		46,143,042		45,562,297		—		—		45,562,297
Accrued interest receivable		227,921		227,921		—		33,900		194,021
Mortgage servicing rights		87,742		87,742		—		—		87,742
SBA servicing asset		6,209		6,209		—		—		6,209
Interest rate swap – non-designated hedge		175,155		175,155		—		175,155		—
Other derivative financial instruments (mortgage banking related)		2,107		2,107		—		2,107		—
Financial liabilities:
Deposits
Noninterest-bearing		13,757,255		13,757,255		—		13,757,255		—
Interest-bearing other than time deposits		32,422,118		32,422,118		—		32,422,118		—
Time deposits		7,158,242		7,133,462		—		7,133,462		—
Federal funds purchased and securities sold under agreements to repurchase		679,337		679,337		—		679,337		—
Corporate and subordinated debentures		752,798		756,080		—		756,080		—
Other borrowings		—		—		—		—		—
Accrued interest payable		39,694		39,694		—		39,694		—
Interest rate swap – non-designated hedge		698,392		698,392		—		698,392		—
Other derivative financial instruments (mortgage banking related)		541		541		—		541		—
December 31, 2024
Financial assets:
Cash and cash equivalents	$	1,392,067	$	1,392,067	$	1,392,067	$	—	$	—
Trading securities		102,932		102,932		—		102,932		—
Investment securities		6,798,876		6,378,734		187,266		6,155,120		36,348
Loans held for sale		279,426		281,662		—		281,662		—
Loans, net of allowance for credit losses		33,437,647		32,448,618		—		—		32,448,618
Accrued interest receivable		163,402		163,402		—		25,035		138,367
Mortgage servicing rights		89,795		89,795		—		—		89,795
SBA servicing asset		6,028		6,028		—		—		6,028
Interest rate swap – non-designated hedge		160,407		160,407		—		160,407		—
Other derivative financial instruments (mortgage banking related)		1,083		1,083		—		1,083		—
Financial liabilities:
Deposits
Noninterest-bearing		10,192,117		10,192,117		—		10,192,117		—
Interest-bearing other than time deposits		23,703,027		23,703,027		—		23,703,027		—
Time deposits		4,165,722		4,145,687		—		4,145,687		—
Federal funds purchased and securities sold under agreements to repurchase		514,912		514,912		—		514,912		—
Corporate and subordinated debentures		391,534		377,616		—		377,616		—
Accrued interest payable		40,739		40,739		—		40,739		—
Interest rate swap – non-designated hedge		878,046		878,046		—		878,046		—
Other derivative financial instruments (mortgage banking related)		1,809		1,809		—		1,809		—

Mortgage Servicing Rights

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, 2025	$	89,795
Servicing assets that resulted from transfers of financial assets		2,056
Changes in fair value due to valuation inputs or assumptions		(3,081)
Changes in fair value due to decay		(1,028)
Fair value, March 31, 2025	$	87,742

SBA servicing asset

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, 2025	$	6,028
Servicing assets that resulted from transfers of financial assets		420
Changes in fair value due to decay		(301)
Changes in fair value due to valuation inputs or assumptions		62
Fair value, March 31, 2025	$	6,209