SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Premises and Equipment (Details) - USD ($) $ in Millions |
12 Months Ended | |
---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
|
Other Assets | ||
Property, Plant and Equipment [Line Items] | ||
Premises held-for-sale | $ 1.1 | $ 5.2 |
Minimum | Buildings and improvements, including leasehold improvements | ||
Property, Plant and Equipment [Line Items] | ||
Useful life | 10 years | |
Minimum | Furniture and equipment | ||
Property, Plant and Equipment [Line Items] | ||
Useful life | 3 years | |
Maximum | Buildings and improvements, including leasehold improvements | ||
Property, Plant and Equipment [Line Items] | ||
Useful life | 40 years | |
Maximum | Furniture and equipment | ||
Property, Plant and Equipment [Line Items] | ||
Useful life | 15 years |