FAIR VALUE MEASUREMENT - Fair Value Measurements, Narrative (Details)	12 Months Ended
Dec. 31, 2018 source
Available-for-sale Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Number of third party sources used to validate prices	2
Derivative [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Number of third party sources used to validate prices	3

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Period Type:	duration