Goodwill and Other Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2026

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Intangible Assets [Table Text Block]

Changes in the gross carrying amount, accumulated amortization, and net book value for CDIs were as follows:

(in thousands)	Three Months Ended Mar 31, 2026		Year Ended Dec 31, 2025
Core deposit intangibles
Gross carrying amount at the beginning of period	$	88,109	$	88,109
Accumulated amortization	(67,462)		(65,260)
Net book value	$	20,647	$	22,849
Amortization during the period	$	2,203	$	8,811

Schedule of Servicing Assets at Fair Value [Table Text Block]

A summary of changes in the balance of the MSRs asset under the fair value measurement method is as follows:

(in thousands)	Three Months Ended Mar 31, 2026			Year Ended Dec 31, 2025
Mortgage servicing rights
Mortgage servicing rights at beginning of period	$	86,337		$	87,683
Additions	2,246			8,716
Decay	(2,245)			(8,621)
Valuation:
Changes in fair value of asset	1,261			(1,441)
Mortgage servicing rights at end of period	$	87,599		$	86,337
Portfolio of residential mortgage loans serviced for others (“servicing portfolio”)	$	6,144,785		$	6,191,012
Mortgage servicing rights to servicing portfolio	1.43		%	1.39		%

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

The following table shows the estimated future yearly amortization expense for CDIs and decay for MSRs:

(in thousands)	Core Deposit Intangibles		Mortgage Servicing Rights
Nine Months Ended December 31, 2026	$	6,608	$	6,785
2027	8,811		11,573
2028	3,485		11,793
2029	1,681		11,060
2030	62		10,080
2031	—		8,988
Beyond 2031	—		27,320
Total estimated amortization expense and MSRs decay(a)	$	20,647	$	87,599

(a) Includes the decrease in value due to passage of time, including the impact from both regularly scheduled principal payments and partial loan paydowns.