Loans Receivable, Net - Aging Analysis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	$ 17,181,187	$ 16,198,082
Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	32,973	43,455
Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	23,240	6,512
Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	11,551	3,312
Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	83,701	74,095
Non-accrual loans with no ACL	13,669	20,722
Non-accrual loans with ACL	2,268	94
Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	17,097,486	16,123,987
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	1,837,697	1,704,544
Residential real estate | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	133	5,342
Residential real estate | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	2,621	729
Residential real estate | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	2,003	107
Residential real estate | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	8,076	8,740
Non-accrual loans with no ACL	3,319	2,562
Non-accrual loans with ACL	0	0
Residential real estate | Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	1,829,621	1,695,804
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	10,833,841	10,303,306
Commercial real estate | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	10,608	18,134
Commercial real estate | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	4,685	2,439
Commercial real estate | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	5,415	2,161
Commercial real estate | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	28,568	36,414
Non-accrual loans with no ACL	5,715	13,680
Non-accrual loans with ACL	2,145	0
Commercial real estate | Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	10,805,273	10,266,892
Other commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	3,177,051	2,901,863
Other commercial | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	15,680	12,745
Other commercial | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	13,371	774
Other commercial | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	2,698	530
Other commercial | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	33,608	15,925
Non-accrual loans with no ACL	1,839	1,869
Non-accrual loans with ACL	20	7
Other commercial | Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	3,143,443	2,885,938
Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	931,440	888,013
Home equity | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	3,142	3,006
Home equity | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	1,556	1,527
Home equity | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	971	283
Home equity | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	7,664	6,782
Non-accrual loans with no ACL	1,995	1,966
Non-accrual loans with ACL	0	0
Home equity | Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	923,776	881,231
Other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	401,158	400,356
Other consumer | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	3,410	4,228
Other consumer | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	1,007	1,043
Other consumer | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	464	231
Other consumer | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	5,785	6,234
Non-accrual loans with no ACL	801	645
Non-accrual loans with ACL	103	87
Other consumer | Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	$ 395,373	$ 394,122