Business Combinations (Details) $ in Thousands		12 Months Ended
	Aug. 01, 2024 USD ($) branch shares	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Apr. 03, 2023 USD ($)	Dec. 31, 2022 USD ($)
Business Acquisition [Line Items]
Assets		$ 64,879,668	$ 56,259,934		$ 52,949,649
Deposits		52,512,349	45,397,170
Goodwill		796,942	$ 656,672
Macatawa Bank Corporation
Business Acquisition [Line Items]
Assets	$ 2,700,000
Deposits	2,300,000
Loan	$ 1,400,000
Macatawa Bank Corporation
Business Acquisition [Line Items]
Business acquisition, number of shares issued (in shares) | shares	4,700,000
Fair value of consideration paid	$ 499,300
Business combination, number of acquired operating branches | branch	26
Business combination, discount on acquired loans	$ 53,700
Business combination, discount on securities	33,500
Business combination, intangible assets acquired	$ 253,000
Acquisition expenses		$ 4,300
Macatawa Bank Corporation | Macatawa Bank Corporation
Business Acquisition [Line Items]
Number of common stock shares issued for each share of acquiree stock (in shares) | shares	0.137
Rothschild & Co Asset Management U.S.
Business Acquisition [Line Items]
Assets acquired in acquisition				$ 12,600
Goodwill				$ 2,600