Loans Receivable - Originated and Acquired Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 11,354,364		$ 11,414,809
Allowance for credit losses	(125,070)	$ (124,897)	(125,243)	$ (124,423)	$ (121,257)	$ (118,036)
Total loans receivable, net	11,229,294		11,289,566
Loans held-for-sale	9,445		8,768
Unearned income, unamortized premiums and discounts and deferred fees and costs	$ 65,000		68,000
Weighted-average payment deferral in years	1 year
Personal Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 6,584,612		6,782,070
Allowance for credit losses	$ (43,241)	(44,668)	(51,706)	(50,851)	(51,617)	(48,887)
Weighted-average payment deferral in years	0 years
Personal Banking | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 3,324,068		3,428,185
Allowance for credit losses	(14,999)	(16,821)	(18,193)	(17,556)	(19,238)	(19,261)
Loans held-for-sale	$ 9,000		9,000
Weighted-average payment deferral in years	0 years
Personal Banking | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 1,180,486		1,227,858
Allowance for credit losses	$ (5,210)	(5,334)	(5,403)	(5,002)	(5,481)	(5,902)
Weighted-average payment deferral in years	0 years
Personal Banking | Vehicle loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 1,960,928		2,008,601
Allowance for credit losses	(21,364)	(21,061)	(26,911)	(27,283)	(26,166)	(23,059)
Personal Banking | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	119,130		117,426
Allowance for credit losses	$ (1,668)	(1,452)	(1,199)	(1,010)	(732)	(665)
Weighted-average payment deferral in years	0 years
Commercial Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 4,769,752		4,632,739
Allowance for credit losses	$ (81,829)	(80,229)	(73,537)	(73,572)	(69,640)	(69,149)
Weighted-average payment deferral in years	1 year
Commercial Banking | Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 2,665,016		2,628,457
Allowance for credit losses	(50,559)	(54,474)	(51,267)	(50,056)	(45,404)	(44,506)
Loans held-for-sale	$ 681		0
Weighted-average payment deferral in years	1 year
Commercial Banking | Commercial real estate loans - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 362,622		345,553
Allowance for credit losses	$ (3,615)	(4,055)	(3,775)	(3,498)	(3,351)	(4,004)
Weighted-average payment deferral in years	0 years
Commercial Banking | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 1,742,114		1,658,729
Allowance for credit losses	$ (27,655)	$ (21,700)	(18,495)	$ (20,018)	$ (20,885)	$ (20,639)
Weighted-average payment deferral in years	0 years
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 10,774,315		10,773,908
Allowance for credit losses	(119,575)		(118,079)
Total loans receivable, net	10,654,740		10,655,829
Originated | Personal Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	6,278,393		6,441,695
Originated | Personal Banking | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	3,189,086		3,283,299
Originated | Personal Banking | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	1,069,569		1,103,410
Originated | Personal Banking | Vehicle loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	1,905,878		1,943,540
Originated | Personal Banking | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	113,860		111,446
Originated | Commercial Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	4,495,922		4,332,213
Originated | Commercial Banking | Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	2,445,069		2,389,537
Originated | Commercial Banking | Commercial real estate loans - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	338,014		319,195
Originated | Commercial Banking | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	1,712,839		1,623,481
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	580,049		640,901
Allowance for credit losses	(5,495)		(7,164)
Total loans receivable, net	574,554		633,737
Acquired | Personal Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	306,219		340,375
Acquired | Personal Banking | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	134,982		144,886
Acquired | Personal Banking | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	110,917		124,448
Acquired | Personal Banking | Vehicle loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	55,050		65,061
Acquired | Personal Banking | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	5,270		5,980
Acquired | Commercial Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	273,830		300,526
Acquired | Commercial Banking | Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	219,947		238,920
Acquired | Commercial Banking | Commercial real estate loans - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	24,608		26,358
Acquired | Commercial Banking | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 29,275		$ 35,248