Loans Receivable, Net - Aging Analysis (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	$ 16,732,502	$ 16,198,082
Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	35,185	43,455
Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	27,238	6,512
Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	3,796	3,312
Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	86,957	74,095
Non-accrual loans with no ACL	20,650	20,722
Non-accrual loans with ACL	88	94
Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	16,645,545	16,123,987
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	1,752,514	1,704,544
Residential real estate | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	8,920	5,342
Residential real estate | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	0	729
Residential real estate | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	1	107
Residential real estate | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	11,649	8,740
Non-accrual loans with no ACL	2,728	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	1,740,865	1,695,804
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	10,672,269	10,303,306
Commercial real estate | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	12,559	18,134
Commercial real estate | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	15,069	2,439
Commercial real estate | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	2,683	2,161
Commercial real estate | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	44,267	36,414
Non-accrual loans with no ACL	13,956	13,680
Non-accrual loans with ACL	0	0
Commercial real estate | Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	10,628,002	10,266,892
Other commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	3,030,608	2,901,863
Other commercial | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	7,082	12,745
Other commercial | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	11,026	774
Other commercial | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	891	530
Other commercial | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	20,551	15,925
Non-accrual loans with no ACL	1,552	1,869
Non-accrual loans with ACL	0	7
Other commercial | Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	3,010,057	2,885,938
Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	883,062	888,013
Home equity | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	3,395	3,006
Home equity | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	295	1,527
Home equity | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	172	283
Home equity | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	5,650	6,782
Non-accrual loans with no ACL	1,788	1,966
Non-accrual loans with ACL	0	0
Home equity | Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	877,412	881,231
Other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	394,049	400,356
Other consumer | Accruing loans 30-59 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	3,229	4,228
Other consumer | Accruing loans 60-89 days past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	848	1,043
Other consumer | Accruing loans 90 days or more past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	49	231
Other consumer | Past due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	4,840	6,234
Non-accrual loans with no ACL	626	645
Non-accrual loans with ACL	88	87
Other consumer | Current loans receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans receivable	$ 389,209	$ 394,122