Goodwill and Other Acquisition-Related Intangible Assets - Schedule of Amortization of Finite-Lived Acquisition-Related Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Intangibles with finite lives
Accumulated amortization	$ (73,032)	$ (66,710)	$ (65,354)
Intangibles with indefinite lives
Gross carrying amount	196,898	89,599	89,598
Total other acquisition-related intangible assets, net	123,866	22,889	24,244
Community banking
Intangibles with indefinite lives
Total other acquisition-related intangible assets, net	116,948	14,881	15,702
Community banking | Trademark
Intangibles with indefinite lives
Carrying amount	13,800	5,800	5,800
Community banking | Core deposit intangibles
Intangibles with finite lives
Gross carrying amount	154,506	55,206	55,206
Accumulated amortization	(51,358)	(46,125)	(45,304)
Net carrying amount	103,148	9,081	9,902
Specialty finance | Customer list intangibles
Intangibles with finite lives
Gross carrying amount	1,962	1,963	1,962
Accumulated amortization	(1,871)	(1,837)	(1,826)
Net carrying amount	91	126	136
Wealth management | Customer list and other intangibles
Intangibles with finite lives
Gross carrying amount	26,630	26,630	26,630
Accumulated amortization	(19,803)	(18,748)	(18,224)
Net carrying amount	$ 6,827	$ 7,882	$ 8,406