LOANS - Summary of Delinquent and Nonaccrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual Past Due and Still Accruing	$ 11,181	$ 10,331
Total	$ 10,669,803	$ 10,726,193
Percentage of Total Loans Due Nonaccrual	0.10%	0.10%
Financial Asset, Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	$ 48,257	$ 31,087
Percentage of Total Loans	0.45%	0.29%
30-59 Days
Accounts Notes And Loans Receivable [Line Items]
Total	$ 27,564	$ 15,896
Percentage of Total Loans Due 30-59 Days	0.26%	0.15%
60-89 Days
Accounts Notes And Loans Receivable [Line Items]
Total	$ 7,068	$ 2,665
Percentage of Total Loans Due 60-89 Days	0.07%	0.02%
90 Days or More
Accounts Notes And Loans Receivable [Line Items]
Total	$ 2,444	$ 2,195
Percentage of Total Loans Due 90 Days or More	0.02%	0.02%
Financial Asset, Not Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	$ 10,621,546	$ 10,695,106
Residential Properties
Accounts Notes And Loans Receivable [Line Items]
Total	6,360,811	6,377,224
Commercial real estate
Accounts Notes And Loans Receivable [Line Items]
Total	1,154,519	1,202,063
Land and Construction
Accounts Notes And Loans Receivable [Line Items]
Total	165,216	157,630
Commercial and Industrial Loans
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual Past Due and Still Accruing	4,694	3,228
Total	2,985,367	2,984,758
Commercial and Industrial Loans | Financial Asset, Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	8,354	6,090
Commercial and Industrial Loans | 30-59 Days
Accounts Notes And Loans Receivable [Line Items]
Total	1,200	385
Commercial and Industrial Loans | 60-89 Days
Accounts Notes And Loans Receivable [Line Items]
Total	233	1,495
Commercial and Industrial Loans | 90 Days or More
Accounts Notes And Loans Receivable [Line Items]
Total	2,227	982
Commercial and Industrial Loans | Financial Asset, Not Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	2,977,013	2,978,668
Consumer Loans
Accounts Notes And Loans Receivable [Line Items]
Total	3,890	4,518
Consumer Loans | Financial Asset, Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	10	167
Consumer Loans | 30-59 Days
Accounts Notes And Loans Receivable [Line Items]
Total	10
Consumer Loans | 60-89 Days
Accounts Notes And Loans Receivable [Line Items]
Total		167
Consumer Loans | Financial Asset, Not Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	3,880	4,351
Real Estate Loans | Residential Properties
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual Past Due and Still Accruing	2,518	2,556
Total	6,360,811	6,377,224
Real Estate Loans | Residential Properties | Financial Asset, Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	22,790	3,124
Real Estate Loans | Residential Properties | 30-59 Days
Accounts Notes And Loans Receivable [Line Items]
Total	20,272	511
Real Estate Loans | Residential Properties | 60-89 Days
Accounts Notes And Loans Receivable [Line Items]
Total		57
Real Estate Loans | Residential Properties | Financial Asset, Not Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	6,338,021	6,374,100
Real Estate Loans | Commercial real estate
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual Past Due and Still Accruing	3,969	4,547
Total	1,154,519	1,202,063
Real Estate Loans | Commercial real estate | Financial Asset, Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	9,747	21,706
Real Estate Loans | Commercial real estate | 30-59 Days
Accounts Notes And Loans Receivable [Line Items]
Total	5,561	15,000
Real Estate Loans | Commercial real estate | 60-89 Days
Accounts Notes And Loans Receivable [Line Items]
Total		946
Real Estate Loans | Commercial real estate | 90 Days or More
Accounts Notes And Loans Receivable [Line Items]
Total	217	1,213
Real Estate Loans | Commercial real estate | Financial Asset, Not Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	1,144,772	1,180,357
Real Estate Loans | Land and Construction
Accounts Notes And Loans Receivable [Line Items]
Total	165,216	157,630
Real Estate Loans | Land and Construction | Financial Asset, Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	7,356
Real Estate Loans | Land and Construction | 30-59 Days
Accounts Notes And Loans Receivable [Line Items]
Total	521
Real Estate Loans | Land and Construction | 60-89 Days
Accounts Notes And Loans Receivable [Line Items]
Total	6,835
Real Estate Loans | Land and Construction | Financial Asset, Not Past Due
Accounts Notes And Loans Receivable [Line Items]
Total	$ 157,860	$ 157,630