Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contracts with Customers
Net interest income (expense)	$ 636,127	$ 613,549	$ 530,559
Not in scope of Topic 606	30,059	11,693	25,149
Total noninterest income	200,815	179,525	184,916
Total revenue	836,942	793,074	715,475
Retail Banking
Revenue from Contracts with Customers
Net interest income (expense)	458,125	436,228	385,656
Not in scope of Topic 606	7,069	6,199	8,270
Total noninterest income	97,651	94,085	91,672
Total revenue	555,776	530,313	477,328
Commercial Banking
Revenue from Contracts with Customers
Net interest income (expense)	175,569	157,128	162,997
Not in scope of Topic 606	5,480	6,709	6,491
Total noninterest income	75,358	77,539	72,781
Total revenue	250,927	234,667	235,778
Treasury and Other
Revenue from Contracts with Customers
Net interest income (expense)	2,433	20,193	(18,094)
Not in scope of Topic 606	17,510	(1,215)	10,388
Total noninterest income	27,806	7,901	20,463
Total revenue	30,239	28,094	2,369
Service charges on deposit accounts.
Revenue from Contracts with Customers
Revenue by type of service	29,647	28,809	27,510
Service charges on deposit accounts. | Retail Banking
Revenue from Contracts with Customers
Revenue by type of service	26,432	25,871	24,413
Service charges on deposit accounts. | Commercial Banking
Revenue from Contracts with Customers
Revenue by type of service	2,786	1,972	1,225
Service charges on deposit accounts. | Treasury and Other
Revenue from Contracts with Customers
Revenue by type of service	429	966	1,872
Credit and debit card fees
Revenue from Contracts with Customers
Revenue by type of service	61,504	63,633	61,143
Credit and debit card fees | Commercial Banking
Revenue from Contracts with Customers
Revenue by type of service	56,651	58,659	55,728
Credit and debit card fees | Treasury and Other
Revenue from Contracts with Customers
Revenue by type of service	4,853	4,974	5,415
Other service charges and fees.
Revenue from Contracts with Customers
Revenue by type of service	29,125	29,193	29,058
Other service charges and fees. | Retail Banking
Revenue from Contracts with Customers
Revenue by type of service	25,162	25,062	23,917
Other service charges and fees. | Commercial Banking
Revenue from Contracts with Customers
Revenue by type of service	1,819	2,243	3,547
Other service charges and fees. | Treasury and Other
Revenue from Contracts with Customers
Revenue by type of service	2,144	1,888	1,594
Trust and investment services income
Revenue from Contracts with Customers
Revenue by type of service	38,449	36,465	34,719
Trust and investment services income | Retail Banking
Revenue from Contracts with Customers
Revenue by type of service	38,449	36,465	34,719
Other.
Revenue from Contracts with Customers
Revenue by type of service	12,031	9,732	7,337
Other. | Retail Banking
Revenue from Contracts with Customers
Revenue by type of service	539	488	353
Other. | Commercial Banking
Revenue from Contracts with Customers
Revenue by type of service	8,622	7,956	5,790
Other. | Treasury and Other
Revenue from Contracts with Customers
Revenue by type of service	$ 2,870	$ 1,288	$ 1,194