MERGER - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Feb. 01, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
MERGER
Increase to goodwill resulting from merger	$ 458
Fair value of assets acquired:
Premises and fixed assets	37,900
Operating lease assets	45,600
Fair value of liabilities assumed:
Deposits	5,410,000
Operating lease liabilities	45,300
Total liabilities assumed		$ 5,847,505
Goodwill resulting from Merger		$ 155,797	$ 55,638	$ 55,638	$ 55,638
Bridge assets acquired
Purchase price consideration:
Purchase price consideration	491,210
Fair value of assets acquired:
Cash and due from banks	715,988
Securities available-for-sale	651,997
Loans held for sale	10,000
Loans held for investment	4,531,640
Premises and fixed assets	37,881
Restricted stock	23,362
BOLI	94,085
Other intangible assets	10,984
Operating lease assets	45,603
Other assets	117,016
Total assets acquired	6,238,556
Fair value of liabilities assumed:
Deposits	5,405,575
Other short-term borrowings	216,298
Subordinated debt	83,200
Operating lease liabilities	45,285
Other liabilities	97,147
Total liabilities assumed	5,847,505
Fair value of net identifiable assets	391,051
Goodwill resulting from Merger	$ 100,159