SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Premises and Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Premises and Equipment
Right-of-use lease asset	$ 45,857	$ 52,348
Lease liability	$ 47,191	$ 52,632
Office buildings and improvements | Minimum
Premises and Equipment
Useful life	5 years
Office buildings and improvements | Maximum
Premises and Equipment
Useful life	39 years
Equipment | Minimum
Premises and Equipment
Useful life	1 year
Equipment | Maximum
Premises and Equipment
Useful life	7 years