GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Estimated Annual Amortization Expense) (Details) - Core Deposit Intangibles [Member] - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year	$ 3,892
Finite-Lived Intangible Asset, Expected Amortization, Year One	3,814
Finite-Lived Intangible Asset, Expected Amortization, Year Two	2,659
Finite-Lived Intangible Asset, Expected Amortization, Year Three	1,575
Finite-Lived Intangible Asset, Expected Amortization, Year Four	904
Thereafter	587
Finite lived assets, net	$ 13,431	$ 14,855	$ 21,426