FAIR VALUE MEASURES - Fair Value Measurements of Assets Measured at Fair Value on Non-Recurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	$ 105,672	$ 38,596
Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	64,773	0
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	40,899	38,596
Other loans held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	64,773
Other loans held for sale | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0
Other loans held for sale | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	64,773
Other loans held for sale | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0
Impaired loans carried at fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	30,986	28,653
Impaired loans carried at fair value | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Impaired loans carried at fair value | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Impaired loans carried at fair value | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	30,986	28,653
Other real estate owned
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	407	408
Other real estate owned | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Other real estate owned | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Other real estate owned | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	407	408
Purchased other real estate owned
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	9,506	9,535
Purchased other real estate owned | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Purchased other real estate owned | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Purchased other real estate owned | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	$ 9,506	$ 9,535