Business Combinations - Assets Acquired and Liabilities Assumed in Acquisition (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 01, 2021	Nov. 16, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets acquired:
Goodwill	$ 1,459,008			$ 1,382,442	$ 1,373,625
Westchester Bank Holding Corporation
Assets acquired:
Cash and cash equivalents		$ 332,221
Held to maturity debt securities		9,197
Loans, net		908,023
Premises and equipment		1,356
Right of use asset		5,873
Bank owned life insurance		28,756
Accrued interest receivable		2,179
Goodwill		63,469
Other intangible assets	$ 8,100	8,130
Other assets		22,861
Total assets acquired		1,382,065
Deposits:
Non-interest bearing		434,780
Savings, NOW and money market		636,569
Total deposits		90,635
Total deposits		1,161,984
Lease liabilities		5,873
Accrued expense and other liabilities		3,074
Total liabilities assumed		1,170,931
Common stock issued in acquisition		$ 211,134
DV Entities
Assets acquired:
Goodwill			$ 13,100
Other intangible assets			$ 2,100