FAIR VALUE MEASURES - Fair Value Measurements of Assets Measured at Fair Value on Non-Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	$ 33,564	$ 37,018
Level 1
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	0	0
Level 2
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	0	0
Level 3
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	33,564	37,018
Impaired loans carried at fair value
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	26,133	27,684
Impaired loans carried at fair value | Level 1
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	0	0
Impaired loans carried at fair value | Level 2
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	0	0
Impaired loans carried at fair value | Level 3
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	26,133	27,684
Other real estate owned
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	708	323
Other real estate owned | Level 1
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	0	0
Other real estate owned | Level 2
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	0	0
Other real estate owned | Level 3
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	708	323
Purchased other real estate owned
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	6,723	9,011
Purchased other real estate owned | Level 1
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	0	0
Purchased other real estate owned | Level 2
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	0	0
Purchased other real estate owned | Level 3
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Nonrecurring assets at fair value	$ 6,723	$ 9,011