Goodwill and Other Acquisition-Related Intangible Assets - Schedule of Amortization of Finite-Lived Acquisition-Related Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025	Sep. 30, 2025
Intangibles with finite lives
Accumulated amortization	$ (114,763)	$ (100,198)	$ (95,199)
Intangibles with indefinite lives
Gross carrying amount	224,796	198,197	200,496
Total other acquisition-related intangible assets, net	110,033	97,999	105,297
Community banking
Intangibles with indefinite lives
Total other acquisition-related intangible assets, net	79,186	92,745	99,727
Community banking \| Trademark
Intangibles with indefinite lives
Carrying amount	11,500	11,500	13,800
Community banking \| Core deposit intangibles
Intangibles with finite lives
Gross carrying amount	158,106	158,106	158,106
Accumulated amortization	(90,420)	(76,861)	(72,179)
Net carrying amount	67,686	81,245	85,927
Specialty finance \| Customer list intangibles
Intangibles with finite lives
Gross carrying amount	1,960	1,961	1,960
Accumulated amortization	(1,960)	(1,932)	(1,924)
Net carrying amount	0	29	36
Wealth management \| Customer list and other intangibles
Intangibles with finite lives
Gross carrying amount	53,230	26,630	26,630
Accumulated amortization	(22,383)	(21,405)	(21,096)
Net carrying amount	$ 30,847	$ 5,225	$ 5,534

Amount of accumulated amortization of finite-lived intangible asset. Excludes goodwill and capitalized cost for software to be sold, leased, or marketed.

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